unleashed-firmware/lib/ST25RFAL002/source/rfal_nfcDep.c

/******************************************************************************
  * \attention
  *
  * <h2><center>&copy; COPYRIGHT 2020 STMicroelectronics</center></h2>
  *
  * Licensed under ST MYLIBERTY SOFTWARE LICENSE AGREEMENT (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        www.st.com/myliberty
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
  * AND SPECIFICALLY DISCLAIMING THE IMPLIED WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
******************************************************************************/

/*
 *      PROJECT:   NFCC firmware
 *      LANGUAGE:  ISO C99
 */

/*! \file rfal_nfcDep.c
 *
 *  \author  Gustavo Patricio
 *
 *  \brief Implementation of NFC-DEP protocol
 *  
 *  NFC-DEP is also known as NFCIP - Near Field Communication 
 *  Interface and Protocol
 *  
 *  This implementation was based on the following specs:
 *    - NFC Forum Digital 1.1
 *    - ECMA 340 3rd Edition 2013
 *
 */

/*
 ******************************************************************************
 * INCLUDES
 ******************************************************************************
 */
#include "rfal_nfcDep.h"
#include "rfal_nfcf.h"
#include "utils.h"

/*
 ******************************************************************************
 * ENABLE SWITCH
 ******************************************************************************
 */

#if RFAL_FEATURE_NFC_DEP

/* Check for valid Block/Payload length  Digital 2.0 Table 90*/
#if((RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN != 64) && (RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN != 128) && \
    (RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN != 192) && (RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN != 254))
#error \
    " RFAL: Invalid NFC-DEP Block Max length. Please change RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN. "
#endif

/* Check for valid PDU length */
#if((RFAL_FEATURE_NFC_DEP_PDU_MAX_LEN < RFAL_FEATURE_NFC_DEP_BLOCK_MAX_LEN))
#error " RFAL: Invalid NFC-DEP PDU Max length. Please change RFAL_FEATURE_NFC_DEP_PDU_MAX_LEN. "
#endif

/*
 ******************************************************************************
 * DEFINES
 ******************************************************************************
 */
#define NFCIP_ATR_RETRY_MAX 2U /*!< Max consecutive retrys of an ATR REQ with transm error*/

#define NFCIP_PSLPAY_LEN (2U) /*!< PSL Payload length (BRS + FSL)                        */
#define NFCIP_PSLREQ_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< PSL REQ length (incl LEN)                             */
#define NFCIP_PSLRES_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< PSL RES length (incl LEN)                             */

#define NFCIP_ATRREQ_BUF_LEN \
    (RFAL_NFCDEP_ATRREQ_MAX_LEN + RFAL_NFCDEP_LEN_LEN) /*!< ATR REQ max length (incl LEN)     */
#define NFCIP_ATRRES_BUF_LEN \
    (RFAL_NFCDEP_ATRRES_MAX_LEN + RFAL_NFCDEP_LEN_LEN) /*!< ATR RES max length (incl LEN)     */

#define NFCIP_RLSREQ_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< RLS REQ length (incl LEN)                             */
#define NFCIP_RLSRES_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< RSL RES length (incl LEN)                             */
#define NFCIP_RLSRES_MIN \
    (2U + RFAL_NFCDEP_LEN_LEN) /*!< Minimum length for a RLS RES (incl LEN)               */

#define NFCIP_DSLREQ_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< DSL REQ length (incl LEN)                             */
#define NFCIP_DSLRES_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< DSL RES length (incl LEN)                             */
#define NFCIP_DSLRES_MIN \
    (2U + RFAL_NFCDEP_LEN_LEN) /*!< Minimum length for a DSL RES (incl LEN)               */

#define NFCIP_DSLRES_MAX_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< Maximum length for a DSL RES (incl LEN)               */
#define NFCIP_RLSRES_MAX_LEN \
    (3U + RFAL_NFCDEP_LEN_LEN) /*!< Minimum length for a RLS RES (incl LEN)               */
#define NFCIP_TARGET_RES_MAX \
    (MAX(NFCIP_RLSRES_MAX_LEN, NFCIP_DSLRES_MAX_LEN)) /*!< Max target control res length    */

#define NFCIP_NO_FWT RFAL_FWT_NONE /*!< No FWT value - Target Mode                            */
#define NFCIP_INIT_MIN_RTOX 1U /*!< Minimum RTOX value  Digital 1.0  14.8.4.1             */
#define NFCIP_INIT_MAX_RTOX 59U /*!< Maximum RTOX value  Digital 1.0  14.8.4.1             */

#define NFCIP_TARG_MIN_RTOX 1U /*!< Minimum target RTOX value  Digital 1.0  14.8.4.1      */
#define NFCIP_TARG_MAX_RTOX 59U /*!< Maximum target RTOX value  Digital 1.0  14.8.4.1      */

#define NFCIP_TRECOV 1280U /*!< Digital 1.0  A.10  Trecov                             */

#define NFCIP_TIMEOUT_ADJUSTMENT \
    3072U /*!< Timeout Adjustment to compensate timing from end of Tx to end of frame  */
#define NFCIP_RWT_ACTIVATION \
    (0x1000001U +            \
     NFCIP_TIMEOUT_ADJUSTMENT) /*!< Digital 2.2  B.11  RWT ACTIVATION  2^24 + RWT Delta + Adjustment*/
#define NFCIP_RWT_ACM_ACTIVATION \
    (0x200001U +                 \
     NFCIP_TIMEOUT_ADJUSTMENT) /*!< Digital 2.2  B.11  RWT ACTIVATION  2^21 + RWT Delta + Adjustment*/

#define RFAL_NFCDEP_HEADER_PAD       \
    (RFAL_NFCDEP_DEPREQ_HEADER_LEN - \
     RFAL_NFCDEP_LEN_MIN) /*!< Difference between expected rcvd header len and max foreseen */

#ifndef RFAL_NFCDEP_MAX_TX_RETRYS
#define RFAL_NFCDEP_MAX_TX_RETRYS \
    (uint8_t)3U /*!< Number of retransmit retyrs                           */
#endif /* RFAL_NFCDEP_MAX_TX_RETRYS */

#ifndef RFAL_NFCDEP_TO_RETRYS
#define RFAL_NFCDEP_TO_RETRYS \
    (uint8_t)3U /*!< Number of retrys for Timeout                          */
#endif /* RFAL_NFCDEP_TO_RETRYS */

#ifndef RFAL_NFCDEP_MAX_RTOX_RETRYS
#define RFAL_NFCDEP_MAX_RTOX_RETRYS \
    (uint8_t)10U /*!< Number of retrys for RTOX    Digital 2.0 17.12.4.3    */
#endif /* RFAL_NFCDEP_MAX_RTOX_RETRYS */

#ifndef RFAL_NFCDEP_MAX_NACK_RETRYS
#define RFAL_NFCDEP_MAX_NACK_RETRYS \
    (uint8_t)3U /*!< Number of retrys for NACK                             */
#endif /* RFAL_NFCDEP_MAX_NACK_RETRYS */

#ifndef RFAL_NFCDEP_MAX_ATN_RETRYS
#define RFAL_NFCDEP_MAX_ATN_RETRYS \
    (uint8_t)3U /*!< Number of retrys for ATN                              */
#endif /* RFAL_NFCDEP_MAX_ATN_RETRYS */

#define NFCIP_MIN_TXERROR_LEN \
    4U /*!< Minimum frame length with error to be ignored  Digital 1.0 14.12.5.4 */

#define NFCIP_REQ (uint8_t)0xD4U /*!<NFCIP REQuest code                                     */
#define NFCIP_RES (uint8_t)0xD5U /*!<NFCIP RESponce code                                    */

#define NFCIP_BS_MASK 0x0FU /*!< Bit mask for BS value on a ATR REQ/RES                */
#define NFCIP_BR_MASK NFCIP_BS_MASK /*!< Bit mask for BR value on a ATR REQ/RES                */

#define NFCIP_PP_GB_MASK 0x02U /*!< Bit mask for GB value in PP byte on a ATR REQ/RES     */
#define NFCIP_PP_NAD_MASK 0x01U /*!< Bit mask for NAD value in PP byte on a ATR REQ/RES    */

#define NFCIP_PFB_xPDU_MASK 0xE0U /*!< Bit mask for PDU type                                 */
#define NFCIP_PFB_IPDU 0x00U /*!< Bit mask indicating a Information PDU                 */
#define NFCIP_PFB_RPDU 0x40U /*!< Bit mask indicating a Response PDU                    */
#define NFCIP_PFB_SPDU 0x80U /*!< Bit mask indicating a Supervisory PDU                 */

#define NFCIP_PFB_MI_BIT 0x10U /*!< Bit mask for the chaining bit (MI) of PFB             */
#define NFCIP_PFB_DID_BIT 0x04U /*!< Bit mask for the DID presence bit of PFB              */
#define NFCIP_PFB_NAD_BIT 0x08U /*!< Bit mask for the NAD presence bit of PFB              */
#define NFCIP_PFB_PNI_MASK 0x03U /*!< Bit mask for the Packet Number Information            */

#define NFCIP_PFB_Rx_MASK 0x10U /*!< Bit mask for the R-PDU type                           */
#define NFCIP_PFB_ACK 0x00U /*!< Bit mask for R-PDU indicating ACK                     */
#define NFCIP_PFB_NACK 0x10U /*!< Bit mask for R-PDU indicating NAK                     */

#define NFCIP_PFB_Sx_MASK 0x10U /*!< Bit mask for the R-PDU type                           */
#define NFCIP_PFB_ATN 0x00U /*!< Bit mask for R-PDU indicating ACK                     */
#define NFCIP_PFB_TO 0x10U /*!< Bit mask for R-PDU indicating NAK                     */

#define NFCIP_PFB_INVALID 0xFFU /*!< Invalid PFB value                                     */

/*
 ******************************************************************************
 * MACROS
 ******************************************************************************
 */

#define nfcipIsTransmissionError(e)              \
    (((e) == ERR_CRC) || ((e) == ERR_FRAMING) || \
     ((e) == ERR_PAR)) /*!< Checks if is a Trasmission error */

#define nfcipConv1FcToMs(v) \
    (rfalConv1fcToMs((v)) + 1U) /*!< Converts value v 1fc into milliseconds (fc=13.56)     */

#define nfcipCmdIsReq(cmd) \
    (((uint8_t)(cmd) % 2U) == 0U) /*!< Checks if the nfcip cmd is a REQ                      */

#define nfcip_PFBhasDID(pfb)      \
    (((pfb)&NFCIP_PFB_DID_BIT) == \
     NFCIP_PFB_DID_BIT) /*!< Checks if pfb is signalling DID                       */
#define nfcip_PFBhasNAD(pfb)      \
    (((pfb)&NFCIP_PFB_NAD_BIT) == \
     NFCIP_PFB_NAD_BIT) /*!< Checks if pfb is signalling NAD                       */

#define nfcip_PFBisIPDU(pfb)        \
    (((pfb)&NFCIP_PFB_xPDU_MASK) == \
     NFCIP_PFB_IPDU) /*!< Checks if pfb is a Information PDU                    */
#define nfcip_PFBisRPDU(pfb)        \
    (((pfb)&NFCIP_PFB_xPDU_MASK) == \
     NFCIP_PFB_RPDU) /*!< Checks if pfb is Response PDU                         */
#define nfcip_PFBisSPDU(pfb)        \
    (((pfb)&NFCIP_PFB_xPDU_MASK) == \
     NFCIP_PFB_SPDU) /*!< Checks if pfb is a Supervisory PDU                    */

#define nfcip_PFBisIMI(pfb)       \
    (nfcip_PFBisIPDU(pfb) &&      \
     (((pfb)&NFCIP_PFB_MI_BIT) == \
      NFCIP_PFB_MI_BIT)) /*!< Checks if pfb is a Information PDU indicating MI chaining */

#define nfcip_PFBisRNACK(pfb)                              \
    (nfcip_PFBisRPDU(pfb) && (((pfb)&NFCIP_PFB_Rx_MASK) == \
                              NFCIP_PFB_NACK)) /*!< Checks if pfb is a R-PDU indicating NACK  */
#define nfcip_PFBisRACK(pfb)                               \
    (nfcip_PFBisRPDU(pfb) && (((pfb)&NFCIP_PFB_Rx_MASK) == \
                              NFCIP_PFB_ACK)) /*!< Checks if pfb is a R-PDU indicating ACK   */

#define nfcip_PFBisSATN(pfb)                               \
    (nfcip_PFBisSPDU(pfb) && (((pfb)&NFCIP_PFB_Sx_MASK) == \
                              NFCIP_PFB_ATN)) /*!< Checks if pfb is a R-PDU indicating ATN   */
#define nfcip_PFBisSTO(pfb)                                \
    (nfcip_PFBisSPDU(pfb) && (((pfb)&NFCIP_PFB_Sx_MASK) == \
                              NFCIP_PFB_TO)) /*!< Checks if pfb is a R-PDU indicating TO    */

#define nfcip_PFBIPDU(pni) \
    ((uint8_t)(0x00U | NFCIP_PFB_IPDU | ((pni)&NFCIP_PFB_PNI_MASK))) /*!< Returns a PFB I-PDU with the given packet number (pni)                   */
#define nfcip_PFBIPDU_MI(pni) \
    ((uint8_t)(isoDep_PCBIBlock(pni) | NFCIP_PFB_MI_BIT)) /*!< Returns a PFB I-PDU with the given packet number (pni) indicating chaing */

#define nfcip_PFBRPDU(pni) \
    ((uint8_t)(0x00U | NFCIP_PFB_RPDU | ((pni)&NFCIP_PFB_PNI_MASK))) /*!< Returns a PFB R-PDU with the given packet number (pni)                   */
#define nfcip_PFBRPDU_NACK(pni) \
    ((uint8_t)(nfcip_PFBRPDU(pni) | NFCIP_PFB_NACK)) /*!< Returns a PFB R-PDU with the given packet number (pni) indicating NACK   */
#define nfcip_PFBRPDU_ACK(pni) \
    ((uint8_t)(nfcip_PFBRPDU(pni) | NFCIP_PFB_ACK)) /*!< Returns a PFB R-PDU with the given packet number (pni) indicating ACK    */

#define nfcip_PFBSPDU() \
    ((uint8_t)(0x00U | NFCIP_PFB_SPDU)) /*!< Returns a PFB S-PDU                                   */
#define nfcip_PFBSPDU_ATN() \
    ((uint8_t)(nfcip_PFBSPDU() | NFCIP_PFB_ATN)) /*!< Returns a PFB S-PDU indicating ATN                    */
#define nfcip_PFBSPDU_TO() \
    ((uint8_t)(nfcip_PFBSPDU() | NFCIP_PFB_TO)) /*!< Returns a PFB S-PDU indicating TO                     */

#define nfcip_PNIInc(pni) \
    ((uint8_t)(((pni) + 1U) & NFCIP_PFB_PNI_MASK)) /*!< Returns a incremented PNI from the given (pni)        */
#define nfcip_PNIDec(pni) \
    ((uint8_t)(((pni)-1U) & NFCIP_PFB_PNI_MASK)) /*!< Returns a decremented PNI from the given (pni)        */

#define nfcip_PBF_PNI(pfb) \
    ((uint8_t)((           \
        pfb)&NFCIP_PFB_PNI_MASK)) /*!< Returns the Packet Number Information (pni)           */

#define nfcip_PPwGB(lr)    \
    (rfalNfcDepLR2PP(lr) | \
     NFCIP_PP_GB_MASK) /*!< Returns a PP byte containing the given PP value indicating GB                  */

#define nfcip_DIDMax(did) \
    (MIN(                 \
        (did),            \
        RFAL_NFCDEP_DID_MAX)) /*!< Ensures that the given did has proper value  Digital 14.6.2.3 DID [0 14]       */
#define nfcip_RTOXTargMax(wt)                             \
    (uint8_t)(MIN(                                        \
        (RFAL_NFCDEP_RWT_TRG_MAX / rfalNfcDepWT2RWT(wt)), \
        NFCIP_TARG_MAX_RTOX)) /*!< Calculates the Maximum RTOX value for the given wt as a Target */

#define nfcipIsInitiator(st)         \
    (((st) >= NFCIP_ST_INIT_IDLE) && \
     ((st) <=                        \
      NFCIP_ST_INIT_RLS)) /*!< Checks if module is set as Initiator                                           */
#define nfcipIsTarget(st) \
    (!nfcipIsInitiator(   \
        st)) /*!< Checks if module is set as Target                                              */

#define nfcipIsBRAllowed(br, mBR) \
    (((1U << (br)) & (mBR)) !=    \
     0U) /*!< Checks bit rate is allowed by given mask                                       */

#define nfcipIsEmptyDEPEnabled(op) \
    (!nfcipIsEmptyDEPDisabled(     \
        op)) /*!< Checks if empty payload is allowed by operation config  NCI 1.0 Table 81       */
#define nfcipIsEmptyDEPDisabled(op)           \
    (((op)&RFAL_NFCDEP_OPER_EMPTY_DEP_DIS) != \
     0U) /*!< Checks if empty payload is not allowed by operation config  NCI 1.0 Table 81   */

#define nfcipIsRTOXReqEnabled(op) \
    (!nfcipIsRTOXReqDisabled(     \
        op)) /*!< Checks if send a RTOX_REQ is allowed by operation config  NCI 1.0 Table 81     */
#define nfcipIsRTOXReqDisabled(op)           \
    (((op)&RFAL_NFCDEP_OPER_RTOX_REQ_DIS) != \
     0U) /*!< Checks if send a RTOX_REQ is not allowed by operation config  NCI 1.0 Table 81 */

/*! Checks if isDeactivating callback is set and calls it, otherwise returns false */
#define nfcipIsDeactivationPending() \
    ((gNfcip.isDeactivating == NULL) ? false : gNfcip.isDeactivating())

/*! Returns the RWT Activation according to the current communication mode */
#define nfcipRWTActivation()                                                       \
    ((gNfcip.cfg.commMode == RFAL_NFCDEP_COMM_ACTIVE) ? NFCIP_RWT_ACM_ACTIVATION : \
                                                        NFCIP_RWT_ACTIVATION)

#define nfcipRTOXAdjust(v) \
    ((v) - ((v) >> 3)) /*!< Adjust RTOX timer value to a percentage of the total, current 88% */

/*******************************************************************************/

// timerPollTimeoutValue is necessary after timerCalculateTimeout so that system will wake up upon timer timeout.
#define nfcipTimerStart(timer, time_ms)                     \
    do {                                                    \
        platformTimerDestroy(timer);                        \
        (timer) = platformTimerCreate((uint16_t)(time_ms)); \
    } while(0) /*!< Configures and starts the RTOX timer            */
#define nfcipTimerisExpired(timer) \
    platformTimerIsExpired(timer) /*!< Checks RTOX timer has expired                   */
#define nfcipTimerDestroy(timer) \
    platformTimerDestroy(timer) /*!< Destroys RTOX timer                             */

#define nfcipLogE(...) /*!< Macro for the error log method                  */
#define nfcipLogW(...) /*!< Macro for the warning log method                */
#define nfcipLogI(...) /*!< Macro for the info log method                   */
#define nfcipLogD(...) /*!< Macro for the debug log method                  */

/*! Digital 1.1 - 16.12.5.2  The Target SHALL NOT attempt any error recovery and remains in Rx mode upon Transmission or a Protocol Error */
#define nfcDepReEnableRx(rxB, rxBL, rxL)                                 \
    rfalTransceiveBlockingTx(                                            \
        NULL,                                                            \
        0,                                                               \
        (rxB),                                                           \
        (rxBL),                                                          \
        (rxL),                                                           \
        (RFAL_TXRX_FLAGS_DEFAULT | (uint32_t)RFAL_TXRX_FLAGS_NFCIP1_ON), \
        RFAL_FWT_NONE)

/*
 ******************************************************************************
 * LOCAL DATA TYPES
 ******************************************************************************
 */

/*! Struct that holds all DEP parameters/configs for the following communications */
typedef struct {
    uint8_t did; /*!< Device ID (DID) to be used                      */

    uint8_t* txBuf; /*!< Pointer to the Tx buffer to be sent             */
    uint16_t txBufLen; /*!< Length of the data in the txBuf                 */
    uint8_t txBufPaylPos; /*!< Position inside txBuf where data starts         */
    bool txChaining; /*!< Flag indicating chaining on transmission        */

    uint8_t* rxBuf; /*!< Pointer to the Rx buffer for incoming data      */
    uint16_t rxBufLen; /*!< Length of the data in the rxBuf                 */
    uint8_t rxBufPaylPos; /*!< Position inside rxBuf where data is to be placed*/

    uint32_t fwt; /*!< Frame Waiting Time (FWT) to be used             */
    uint32_t dFwt; /*!< Delta Frame Waiting Time (dFWT) to be used      */
    uint16_t fsc; /*!< Frame Size (FSC) to be used                     */

} rfalNfcDepDEPParams;

/*! NFCIP module states */
typedef enum {
    NFCIP_ST_IDLE,
    NFCIP_ST_INIT_IDLE,
    NFCIP_ST_INIT_ATR,
    NFCIP_ST_INIT_PSL,
    NFCIP_ST_INIT_DEP_IDLE,
    NFCIP_ST_INIT_DEP_TX,
    NFCIP_ST_INIT_DEP_RX,
    NFCIP_ST_INIT_DEP_ATN,
    NFCIP_ST_INIT_DSL,
    NFCIP_ST_INIT_RLS,

    NFCIP_ST_TARG_WAIT_ATR,
    NFCIP_ST_TARG_WAIT_ACTV,
    NFCIP_ST_TARG_DEP_IDLE,
    NFCIP_ST_TARG_DEP_RX,
    NFCIP_ST_TARG_DEP_RTOX,
    NFCIP_ST_TARG_DEP_TX,
    NFCIP_ST_TARG_DEP_SLEEP
} rfalNfcDepState;

/*! NFCIP commands (Request, Response) */
typedef enum {
    NFCIP_CMD_ATR_REQ = 0x00,
    NFCIP_CMD_ATR_RES = 0x01,
    NFCIP_CMD_WUP_REQ = 0x02,
    NFCIP_CMD_WUP_RES = 0x03,
    NFCIP_CMD_PSL_REQ = 0x04,
    NFCIP_CMD_PSL_RES = 0x05,
    NFCIP_CMD_DEP_REQ = 0x06,
    NFCIP_CMD_DEP_RES = 0x07,
    NFCIP_CMD_DSL_REQ = 0x08,
    NFCIP_CMD_DSL_RES = 0x09,
    NFCIP_CMD_RLS_REQ = 0x0A,
    NFCIP_CMD_RLS_RES = 0x0B
} rfalNfcDepCmd;

/*! Struct that holds all NFCIP data */
typedef struct {
    rfalNfcDepConfigs cfg; /*!< Holds the current configuration to be used    */

    rfalNfcDepState state; /*!< Current state of the NFCIP module             */
    uint8_t pni; /*!< Packet Number Information (PNI) counter       */

    uint8_t lastCmd; /*!< Last command sent                             */
    uint8_t lastPFB; /*!< Last PFB sent                                 */
    uint8_t lastPFBnATN; /*!< Last PFB sent (excluding  ATN)                */
    uint8_t lastRTOX; /*!< Last RTOX value sent                          */

    uint8_t cntTxRetrys; /*!< Retransmissions counter                       */
    uint8_t cntTORetrys; /*!< Timeouts counter                              */
    uint8_t cntRTOXRetrys; /*!< RTOX counter                                  */
    uint8_t cntNACKRetrys; /*!< NACK counter                                  */
    uint8_t cntATNRetrys; /*!< Attention (ATN) counter                       */

    uint16_t fsc; /*!< Current Frame Size (FSC) to be used           */
    bool isTxChaining; /*!< Flag for chaining on Transmission             */
    bool isRxChaining; /*!< Flag for chaining on Reception                */
    uint8_t* txBuf; /*!< Pointer to the Tx buffer to be sent           */
    uint8_t* rxBuf; /*!< Pointer to the Rx buffer for incoming data    */
    uint16_t txBufLen; /*!< Length of the data in the txBuf               */
    uint16_t rxBufLen; /*!< Length of rxBuf buffer                        */
    uint16_t* rxRcvdLen; /*!< Length of the data in the rxBuf               */
    uint8_t txBufPaylPos; /*!< Position in txBuf where data starts           */
    uint8_t rxBufPaylPos; /*!< Position in rxBuf where data is to be placed  */
    bool* isChaining; /*!< Flag for chaining on Reception                */

    rfalNfcDepDevice* nfcDepDev; /*!< Pointer to NFC-DEP device info                */

    uint32_t RTOXTimer; /*!< Timer used for RTOX                           */
    rfalNfcDepDeactCallback isDeactivating; /*!< Deactivating flag check callback              */

    bool isReqPending; /*!< Flag pending REQ from Target activation       */
    bool isTxPending; /*!< Flag pending DEP Block while waiting RTOX Ack */
    bool isWait4RTOX; /*!< Flag for waiting RTOX Ack                     */

    rfalNfcDepPduTxRxParam PDUParam; /*!< PDU TxRx params                               */
    uint16_t PDUTxPos; /*!< PDU Tx position                               */
    uint16_t PDURxPos; /*!< PDU Rx position                               */
    bool isPDURxChaining; /*!< PDU Transceive chaining flag                  */
} rfalNfcDep;

/*
 ******************************************************************************
 * LOCAL VARIABLES
 ******************************************************************************
 */

static rfalNfcDep gNfcip; /*!< NFCIP module instance                         */

/*
 ******************************************************************************
 * LOCAL FUNCTION PROTOTYPES
 ******************************************************************************
 */

static ReturnCode nfcipTxRx(
    rfalNfcDepCmd cmd,
    uint8_t* txBuf,
    uint32_t fwt,
    uint8_t* paylBuf,
    uint8_t paylBufLen,
    uint8_t* rxBuf,
    uint16_t rxBufLen,
    uint16_t* rxActLen);
static ReturnCode nfcipTx(
    rfalNfcDepCmd cmd,
    uint8_t* txBuf,
    uint8_t* paylBuf,
    uint16_t paylLen,
    uint8_t pfbData,
    uint32_t fwt);
static ReturnCode nfcipDEPControlMsg(uint8_t pfb, uint8_t RTOX);
static ReturnCode nfcipInitiatorHandleDEP(
    ReturnCode rxRes,
    uint16_t rxLen,
    uint16_t* outActRxLen,
    bool* outIsChaining);
static ReturnCode
    nfcipTargetHandleRX(ReturnCode rxRes, uint16_t* outActRxLen, bool* outIsChaining);
static ReturnCode nfcipTargetHandleActivation(rfalNfcDepDevice* nfcDepDev, uint8_t* outBRS);

/*!
 ******************************************************************************
 * \brief NFCIP Configure
 * 
 * Configures the nfcip layer with the given configurations 
 * 
 * \param[in] cfg   : nfcip configuration for following communication
 ******************************************************************************
 */
static void nfcipConfig(const rfalNfcDepConfigs* cfg);

/*!
 ******************************************************************************
 * \brief Set DEP parameters
 * 
 * This method sets the parameters/configs for following Data Exchange
 * Sets the nfcip module state according to the role it is configured
 * 
 * 
 * \warning To be used only after proper Initiator/Target activation: 
 *           nfcipTargetHandleActivation() or nfcipInitiatorActivate() has
 *           returned success
 *           
 *  This must be called before  nfcipRun() in case of Target to pass 
 *  rxBuffer
 *  
 *  Everytime some data needs to be transmitted call this to set it and 
 *  call nfcipRun() until done or error
 * 
 * \param[in]  DEPParams  : the parameters to be used during Data Exchange 
 ******************************************************************************
 */
static void nfcipSetDEPParams(const rfalNfcDepDEPParams* DEPParams);

/*!
 ******************************************************************************
 * \brief NFCIP run protocol
 * 
 * This method handles all the nfcip protocol during Data Exchange (DEP
 *  requests and responses).
 *  
 *  A data exchange cycle is considered a DEP REQ and a DEP RES.
 *  
 *  In case of Tx chaining(MI) must signal it with  nfcipSetDEPParams()
 *  In case of Rx chaining(MI) outIsChaining will be set to true and the 
 *  current data returned
 *  
 * \param[out] outActRxLen   : data received length
 * \param[out] outIsChaining : true if other peer is performing chaining(MI)
 *  
 * \return ERR_NONE    : Data exchange cycle completed successfully
 * \return ERR_TIMEOUT : Timeout occurred
 * \return ERR_PROTO   : Protocol error occurred
 * \return ERR_AGAIN   : Other peer is doing chaining(MI), current block 
 *                       was received successfully call again until complete
 * 
 ******************************************************************************
 */
static ReturnCode nfcipRun(uint16_t* outActRxLen, bool* outIsChaining);

/*!
 ******************************************************************************
 * \brief Transmission method
 * 
 * This method checks if the current communication is Active or Passive
 * and performs the necessary procedures for each communication type
 * 
 * Transmits the data hold in txBuf 
 * 
 * \param[in]  txBuf    : buffer to transmit
 * \param[in]  txBufLen : txBuffer capacity 
 * \param[in]  fwt      : fwt for current Tx
 * 
 * \return ERR_NONE       : No error
 ******************************************************************************
 */
static ReturnCode nfcipDataTx(uint8_t* txBuf, uint16_t txBufLen, uint32_t fwt);

/*!
 ******************************************************************************
 * \brief Reception method
 * 
 * This method checks if the current communication is Active or Passive
 * and calls the appropriate reception method
 * 
 * Copies incoming data to rxBuf
 * 
 * \param[in] blocking    : reception is to be done blocking or non-blocking
 * 
 * \return ERR_BUSY       : Busy
 * \return ERR_NONE       : No error
 ******************************************************************************
 */
static ReturnCode nfcipDataRx(bool blocking);

/*
 ******************************************************************************
 * LOCAL FUNCTIONS
 ******************************************************************************
 */

/*******************************************************************************/

/*******************************************************************************/
static bool nfcipDxIsSupported(uint8_t Dx, uint8_t BRx, uint8_t BSx) {
    uint8_t Bx;

    /* Take the min of the possible bit rates, we'll use one for both directions */
    Bx = MIN(BRx, BSx);

    /* Lower bit rates must be supported for P2P */
    if((Dx <= (uint8_t)RFAL_NFCDEP_Dx_04_424)) {
        return true;
    }

    if((Dx == (uint8_t)RFAL_NFCDEP_Dx_08_848) && (Bx >= (uint8_t)RFAL_NFCDEP_Bx_08_848)) {
        return true;
    }

    return false;
}

/*******************************************************************************/
static ReturnCode nfcipTxRx(
    rfalNfcDepCmd cmd,
    uint8_t* txBuf,
    uint32_t fwt,
    uint8_t* paylBuf,
    uint8_t paylBufLen,
    uint8_t* rxBuf,
    uint16_t rxBufLen,
    uint16_t* rxActLen) {
    ReturnCode ret;

    if((cmd == NFCIP_CMD_DEP_REQ) ||
       (cmd == NFCIP_CMD_DEP_RES)) /* this method cannot be used for DEPs */
    {
        return ERR_PARAM;
    }

    /* Assign the global params for this TxRx */
    gNfcip.rxBuf = rxBuf;
    gNfcip.rxBufLen = rxBufLen;
    gNfcip.rxRcvdLen = rxActLen;

    /*******************************************************************************/
    /* Transmission                                                                */
    /*******************************************************************************/
    if(txBuf != NULL) /* if nothing to Tx, just do Rx */
    {
        EXIT_ON_ERR(ret, nfcipTx(cmd, txBuf, paylBuf, paylBufLen, 0, fwt));
    }

    /*******************************************************************************/
    /* Reception                                                                   */
    /*******************************************************************************/
    ret = nfcipDataRx(true);
    if(ret != ERR_NONE) {
        return ret;
    }

    /*******************************************************************************/
    *rxActLen = *rxBuf; /* Use LEN byte instead due to with/without CRC modes */
    return ERR_NONE; /* Tx and Rx completed successfully                   */
}

/*******************************************************************************/
static ReturnCode nfcipDEPControlMsg(uint8_t pfb, uint8_t RTOX) {
    uint8_t ctrlMsg[20];
    rfalNfcDepCmd depCmd;
    uint32_t fwt;

    /*******************************************************************************/
    /* Calculate Cmd and fwt to be used                                            */
    /*******************************************************************************/
    depCmd =
        ((gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) ? NFCIP_CMD_DEP_RES : NFCIP_CMD_DEP_REQ);
    fwt =
        ((gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) ?
             NFCIP_NO_FWT :
             (nfcip_PFBisSTO(pfb) ? ((RTOX * gNfcip.cfg.fwt) + gNfcip.cfg.dFwt) :
                                    (gNfcip.cfg.fwt + gNfcip.cfg.dFwt)));

    if(nfcip_PFBisSTO(pfb)) {
        ctrlMsg[RFAL_NFCDEP_DEPREQ_HEADER_LEN] = RTOX;
        return nfcipTx(
            depCmd, ctrlMsg, &ctrlMsg[RFAL_NFCDEP_DEPREQ_HEADER_LEN], sizeof(uint8_t), pfb, fwt);
    } else {
        return nfcipTx(depCmd, ctrlMsg, NULL, 0, pfb, fwt);
    }
}

/*******************************************************************************/
static void nfcipClearCounters(void) {
    gNfcip.cntATNRetrys = 0;
    gNfcip.cntNACKRetrys = 0;
    gNfcip.cntTORetrys = 0;
    gNfcip.cntTxRetrys = 0;
    gNfcip.cntRTOXRetrys = 0;
}

/*******************************************************************************/
static ReturnCode nfcipInitiatorHandleDEP(
    ReturnCode rxRes,
    uint16_t rxLen,
    uint16_t* outActRxLen,
    bool* outIsChaining) {
    ReturnCode ret;
    uint8_t nfcDepLen;
    uint8_t rxMsgIt;
    uint8_t rxPFB;
    uint8_t rxRTOX;
    uint8_t optHdrLen;

    ret = ERR_INTERNAL;
    rxMsgIt = 0;
    optHdrLen = 0;

    *outActRxLen = 0;
    *outIsChaining = false;

    /*******************************************************************************/
    /* Handle reception errors                                                     */
    /*******************************************************************************/
    switch(rxRes) {
    /*******************************************************************************/
    /* Timeout ->  Digital 1.0 14.15.5.6 */
    case ERR_TIMEOUT:

        nfcipLogI(" NFCIP(I) TIMEOUT  TORetrys:%d \r\n", gNfcip.cntTORetrys);

        /* Digital 1.0 14.15.5.6 - If nTO >= Max raise protocol error */
        if(gNfcip.cntTORetrys++ >= RFAL_NFCDEP_TO_RETRYS) {
            return ERR_PROTO;
        }

        /*******************************************************************************/
        /* Upon Timeout error, if Deactivation is pending, no more error recovery 
             * will be done #54. 
             * This is used to address the issue some devices that havea big TO. 
             * Normally LLCP layer has timeout already, and NFCIP layer is still
             * running error handling, retrying ATN/NACKs                                  */
        /*******************************************************************************/
        if(nfcipIsDeactivationPending()) {
            nfcipLogI(" skipping error recovery due deactivation pending \r\n");
            return ERR_TIMEOUT;
        }

        /* Digital 1.0 14.15.5.6 1)  If last PDU was NACK */
        if(nfcip_PFBisRNACK(gNfcip.lastPFB)) {
            /* Digital 1.0 14.15.5.6 2)  if NACKs failed raise protocol error  */
            if(gNfcip.cntNACKRetrys++ >= RFAL_NFCDEP_MAX_NACK_RETRYS) {
                return ERR_PROTO;
            }

            /* Send NACK */
            nfcipLogI(" NFCIP(I) Sending NACK retry: %d \r\n", gNfcip.cntNACKRetrys);
            EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBRPDU_NACK(gNfcip.pni), 0));
            return ERR_BUSY;
        }

        nfcipLogI(" NFCIP(I) Checking if to send ATN  ATNRetrys: %d \r\n", gNfcip.cntATNRetrys);

        /* Digital 1.0 14.15.5.6 3)  Otherwise send ATN */
        if(gNfcip.cntATNRetrys++ >= RFAL_NFCDEP_MAX_NACK_RETRYS) {
            return ERR_PROTO;
        }

        /* Send ATN */
        nfcipLogI(" NFCIP(I) Sending ATN \r\n");
        EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBSPDU_ATN(), 0));
        return ERR_BUSY;

    /*******************************************************************************/
    /* Data rcvd with error ->  Digital 1.0 14.12.5.4 */
    case ERR_CRC:
    case ERR_PAR:
    case ERR_FRAMING:
    case ERR_RF_COLLISION:

        nfcipLogI(" NFCIP(I) rx Error: %d \r\n", rxRes);

        /* Digital 1.0 14.12.5.4 Tx Error with data, ignore */
        if(rxLen < NFCIP_MIN_TXERROR_LEN) {
            nfcipLogI(" NFCIP(I) Transmission error w data  \r\n");
#if 0
                if(gNfcip.cfg.commMode == RFAL_NFCDEP_COMM_PASSIVE)
                {
                    nfcipLogI( " NFCIP(I) Transmission error w data -> reEnabling Rx \r\n" );
                    nfcipReEnableRxTout( NFCIP_TRECOV );
                    return ERR_BUSY;
                }
#endif /* 0 */
        }

        /* Digital 1.1 16.12.5.4  if NACKs failed raise Transmission error  */
        if(gNfcip.cntNACKRetrys++ >= RFAL_NFCDEP_MAX_NACK_RETRYS) {
            return ERR_FRAMING;
        }

        /* Send NACK */
        nfcipLogI(" NFCIP(I) Sending NACK  \r\n");
        EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBRPDU_NACK(gNfcip.pni), 0));
        return ERR_BUSY;

    case ERR_NONE:
        break;

    case ERR_BUSY:
        return ERR_BUSY; /* Debug purposes */

    default:
        nfcipLogW(" NFCIP(I) Error: %d \r\n", rxRes);
        return rxRes;
    }

    /*******************************************************************************/
    /* Rx OK check if valid DEP PDU                                                */
    /*******************************************************************************/

    /* Due to different modes on ST25R391x (with/without CRC) use NFC-DEP LEN instead of bytes retrieved */
    nfcDepLen = gNfcip.rxBuf[rxMsgIt++];

    nfcipLogD(" NFCIP(I) rx OK: %d bytes \r\n", nfcDepLen);

    /* Digital 1.0 14.15.5.5 Protocol Error  */
    if(gNfcip.rxBuf[rxMsgIt++] != NFCIP_RES) {
        nfcipLogW(" NFCIP(I) error %02X instead of %02X \r\n", gNfcip.rxBuf[--rxMsgIt], NFCIP_RES);
        return ERR_PROTO;
    }

    /* Digital 1.0 14.15.5.5 Protocol Error  */
    if(gNfcip.rxBuf[rxMsgIt++] != (uint8_t)NFCIP_CMD_DEP_RES) {
        nfcipLogW(
            " NFCIP(I) error %02X instead of %02X \r\n",
            gNfcip.rxBuf[--rxMsgIt],
            NFCIP_CMD_DEP_RES);
        return ERR_PROTO;
    }

    rxPFB = gNfcip.rxBuf[rxMsgIt++];

    /*******************************************************************************/
    /* Check for valid PFB type                                                    */
    if(!(nfcip_PFBisSPDU(rxPFB) || nfcip_PFBisRPDU(rxPFB) || nfcip_PFBisIPDU(rxPFB))) {
        return ERR_PROTO;
    }

    /*******************************************************************************/
    /* Digital 1.0 14.8.2.1  check if DID is expected and match -> Protocol Error  */
    if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
        if((gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.did) || !nfcip_PFBhasDID(rxPFB)) {
            return ERR_PROTO;
        }
        optHdrLen++; /* Inc header optional field cnt*/
    } else if(nfcip_PFBhasDID(rxPFB)) /* DID not expected but rcv */
    {
        return ERR_PROTO;
    } else {
        /* MISRA 15.7 - Empty else */
    }

    /*******************************************************************************/
    /* Digital 1.0 14.6.2.8 & 14.6.3.11 NAD must not be used  */
    if(gNfcip.cfg.nad != RFAL_NFCDEP_NAD_NO) {
        if((gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.nad) || !nfcip_PFBhasNAD(rxPFB)) {
            return ERR_PROTO;
        }
        optHdrLen++; /* Inc header optional field cnt*/
    } else if(nfcip_PFBhasNAD(rxPFB)) /* NAD not expected but rcv */
    {
        return ERR_PROTO;
    } else {
        /* MISRA 15.7 - Empty else */
    }

    /*******************************************************************************/
    /* Process R-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisRPDU(rxPFB)) {
        /*******************************************************************************/
        /* R ACK                                                                       */
        /*******************************************************************************/
        if(nfcip_PFBisRACK(rxPFB)) {
            nfcipLogI(" NFCIP(I) Rcvd ACK  \r\n");
            if(gNfcip.pni == nfcip_PBF_PNI(rxPFB)) {
                /* 14.12.3.3 R-ACK with correct PNI -> Increment */
                gNfcip.pni = nfcip_PNIInc(gNfcip.pni);

                /* R-ACK while not performing chaining -> Protocol error*/
                if(!gNfcip.isTxChaining) {
                    return ERR_PROTO;
                }

                nfcipClearCounters();
                gNfcip.state = NFCIP_ST_INIT_DEP_IDLE;
                return ERR_NONE; /* This block has been transmitted */
            } else /* Digital 1.0 14.12.4.5 ACK with wrong PNI Initiator may retransmit */
            {
                if(gNfcip.cntTxRetrys++ >= RFAL_NFCDEP_MAX_TX_RETRYS) {
                    return ERR_PROTO;
                }

                /* Extended the MAY in Digital 1.0 14.12.4.5 to only reTransmit if the ACK
                 * is for the previous DEP, otherwise raise Protocol immediately 
                 * If the PNI difference is more than 1 it is worthless to reTransmit 3x
                 * and after raise the error                                              */

                if(nfcip_PNIDec(gNfcip.pni) == nfcip_PBF_PNI(rxPFB)) {
                    /* ReTransmit */
                    nfcipLogI(" NFCIP(I) Rcvd ACK prev PNI -> reTx \r\n");
                    gNfcip.state = NFCIP_ST_INIT_DEP_TX;
                    return ERR_BUSY;
                }

                nfcipLogI(" NFCIP(I) Rcvd ACK unexpected far PNI -> Error \r\n");
                return ERR_PROTO;
            }
        } else /* Digital 1.0 - 14.12.5.2 Target must never send NACK  */
        {
            return ERR_PROTO;
        }
    }

    /*******************************************************************************/
    /* Process S-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisSPDU(rxPFB)) {
        nfcipLogI(" NFCIP(I) Rcvd S-PDU  \r\n");
        /*******************************************************************************/
        /* S ATN                                                                       */
        /*******************************************************************************/
        if(nfcip_PFBisSATN(rxPFB)) /* If is a S-ATN        */
        {
            nfcipLogI(" NFCIP(I) Rcvd ATN  \r\n");
            if(nfcip_PFBisSATN(gNfcip.lastPFB)) /* Check if is expected */
            {
                gNfcip.cntATNRetrys = 0; /* Clear ATN counter    */

                /* Although spec is not clear NFC Forum Digital test is expecting to
                 * retransmit upon receiving ATN_RES */
                if(nfcip_PFBisSTO(gNfcip.lastPFBnATN)) {
                    nfcipLogI(" NFCIP(I) Rcvd ATN  -> reTx RTOX_RES \r\n");
                    EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBSPDU_TO(), gNfcip.lastRTOX));
                } else {
                    /* ReTransmit ? */
                    if(gNfcip.cntTxRetrys++ >= RFAL_NFCDEP_MAX_TX_RETRYS) {
                        return ERR_PROTO;
                    }

                    nfcipLogI(" NFCIP(I) Rcvd ATN  -> reTx  PNI: %d \r\n", gNfcip.pni);
                    gNfcip.state = NFCIP_ST_INIT_DEP_TX;
                }

                return ERR_BUSY;
            } else /* Digital 1.0  14.12.4.4 & 14.12.4.8 */
            {
                return ERR_PROTO;
            }
        }
        /*******************************************************************************/
        /* S TO                                                                        */
        /*******************************************************************************/
        else if(nfcip_PFBisSTO(rxPFB)) /* If is a S-TO (RTOX)  */
        {
            nfcipLogI(" NFCIP(I) Rcvd TO  \r\n");

            rxRTOX = gNfcip.rxBuf[rxMsgIt++];

            /* Digital 1.1 16.12.4.3 - Initiator MAY stop accepting subsequent RTOX Req   *
             *                       - RTOX request to an ATN -> Protocol error           */
            if((gNfcip.cntRTOXRetrys++ > RFAL_NFCDEP_MAX_RTOX_RETRYS) ||
               nfcip_PFBisSATN(gNfcip.lastPFB)) {
                return ERR_PROTO;
            }

            /* Digital 1.1 16.8.4.1 RTOX must be between [1,59] */
            if((rxRTOX < NFCIP_INIT_MIN_RTOX) || (rxRTOX > NFCIP_INIT_MAX_RTOX)) {
                return ERR_PROTO;
            }

            EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBSPDU_TO(), rxRTOX));
            gNfcip.lastRTOX = rxRTOX;

            return ERR_BUSY;
        } else {
            /* Unexpected S-PDU */
            return ERR_PROTO; /*  PRQA S  2880 # MISRA 2.1 - Guard code to prevent unexpected behavior */
        }
    }

    /*******************************************************************************/
    /* Process I-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisIPDU(rxPFB)) {
        if(gNfcip.pni != nfcip_PBF_PNI(rxPFB)) {
            nfcipLogI(
                " NFCIP(I) Rcvd IPDU wrong PNI     curPNI: %d rxPNI: %d \r\n",
                gNfcip.pni,
                nfcip_PBF_PNI(rxPFB));
            return ERR_PROTO;
        }

        nfcipLogD(" NFCIP(I) Rcvd IPDU OK    PNI: %d \r\n", gNfcip.pni);

        /* 14.12.3.3 I-PDU with correct PNI -> Increment */
        gNfcip.pni = nfcip_PNIInc(gNfcip.pni);

        /* Successful data Exchange */
        nfcipClearCounters();
        *outActRxLen = ((uint16_t)nfcDepLen - RFAL_NFCDEP_DEP_HEADER - (uint16_t)optHdrLen);

        if((&gNfcip.rxBuf[gNfcip.rxBufPaylPos] !=
            &gNfcip.rxBuf[RFAL_NFCDEP_DEP_HEADER + optHdrLen]) &&
           (*outActRxLen > 0U)) {
            ST_MEMMOVE(
                &gNfcip.rxBuf[gNfcip.rxBufPaylPos],
                &gNfcip.rxBuf[RFAL_NFCDEP_DEP_HEADER + optHdrLen],
                *outActRxLen);
        }

        /*******************************************************************************/
        /* Check if target is indicating chaining MI                                   */
        /*******************************************************************************/
        if(nfcip_PFBisIMI(rxPFB)) {
            gNfcip.isRxChaining = true;
            *outIsChaining = true;

            nfcipLogD(" NFCIP(I) Rcvd IPDU OK w MI -> ACK \r\n");
            EXIT_ON_ERR(
                ret, nfcipDEPControlMsg(nfcip_PFBRPDU_ACK(gNfcip.pni), gNfcip.rxBuf[rxMsgIt++]));

            return ERR_AGAIN; /* Send Again signalling to run again, but some chaining data has arrived*/
        } else {
            gNfcip.isRxChaining = false;
            gNfcip.state = NFCIP_ST_INIT_DEP_IDLE;

            ret = ERR_NONE; /* Data exchange done */
        }
    }
    return ret;
}

/*******************************************************************************/
static ReturnCode
    nfcipTargetHandleRX(ReturnCode rxRes, uint16_t* outActRxLen, bool* outIsChaining) {
    ReturnCode ret;
    uint8_t nfcDepLen;
    uint8_t rxMsgIt;
    uint8_t rxPFB;
    uint8_t optHdrLen;
    uint8_t resBuf[RFAL_NFCDEP_HEADER_PAD + NFCIP_TARGET_RES_MAX];

    ret = ERR_INTERNAL;
    rxMsgIt = 0;
    optHdrLen = 0;

    *outActRxLen = 0;
    *outIsChaining = false;

    /*******************************************************************************/
    /* Handle reception errors                                                     */
    /*******************************************************************************/
    switch(rxRes) {
    /*******************************************************************************/
    case ERR_NONE:
        break;

    case ERR_LINK_LOSS:
        nfcipLogW(" NFCIP(T) Error: %d \r\n", rxRes);
        return rxRes;

    case ERR_BUSY:
        return ERR_BUSY; /* Debug purposes */

    case ERR_TIMEOUT:
    case ERR_CRC:
    case ERR_PAR:
    case ERR_FRAMING:
    case ERR_PROTO:
    default:
        /* Digital 1.1  16.12.5.2 The Target MUST NOT attempt any error recovery.      *
             * The Target MUST always stay in receive mode when a                          *
             * Transmission Error or a Protocol Error occurs.                              *
             *                                                                             *
             * Do not push Transmission/Protocol Errors to upper layer in Listen Mode #766 */

        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY;
    }

    /*******************************************************************************/
    /* Rx OK check if valid DEP PDU                                                */
    /*******************************************************************************/

    /* Due to different modes on ST25R391x (with/without CRC) use NFC-DEP LEN instead of bytes retrieved */
    nfcDepLen = gNfcip.rxBuf[rxMsgIt++];

    nfcipLogD(" NFCIP(T) rx OK: %d bytes \r\n", nfcDepLen);

    if(gNfcip.rxBuf[rxMsgIt++] != NFCIP_REQ) {
        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY; /* ERR_PROTO - Ignore bad request */
    }

    /*******************************************************************************/
    /* Check whether target rcvd a normal DEP or deactivation request              */
    /*******************************************************************************/
    switch(gNfcip.rxBuf[rxMsgIt++]) {
    /*******************************************************************************/
    case(uint8_t)NFCIP_CMD_DEP_REQ:
        break; /* Continue to normal DEP processing */

    /*******************************************************************************/
    case(uint8_t)NFCIP_CMD_DSL_REQ:

        nfcipLogI(" NFCIP(T) rx DSL \r\n");

        /* Digital 1.0  14.9.1.2 If DID is used and incorrect ignore it */
        /* [Digital 1.0, 16.9.1.2]: If DID == 0, Target SHALL ignore DSL_REQ with DID */
        if((((gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.did) ||
             (nfcDepLen != RFAL_NFCDEP_DSL_RLS_LEN_DID)) &&
            (gNfcip.cfg.did != RFAL_NFCDEP_DID_NO)) ||
           ((gNfcip.cfg.did == RFAL_NFCDEP_DID_NO) &&
            (nfcDepLen != RFAL_NFCDEP_DSL_RLS_LEN_NO_DID))) {
            nfcipLogI(" NFCIP(T) DSL wrong DID, ignoring \r\n");
            return ERR_BUSY;
        }

        nfcipTx(NFCIP_CMD_DSL_RES, resBuf, NULL, 0, 0, NFCIP_NO_FWT);

        gNfcip.state = NFCIP_ST_TARG_DEP_SLEEP;
        return ERR_SLEEP_REQ;

    /*******************************************************************************/
    case(uint8_t)NFCIP_CMD_RLS_REQ:

        nfcipLogI(" NFCIP(T) rx RLS \r\n");

        /* Digital 1.0  14.10.1.2 If DID is used and incorrect ignore it */
        /* [Digital 1.0, 16.10.2.2]: If DID == 0, Target SHALL ignore DSL_REQ with DID */
        if((((gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.did) ||
             (nfcDepLen != RFAL_NFCDEP_DSL_RLS_LEN_DID)) &&
            (gNfcip.cfg.did != RFAL_NFCDEP_DID_NO)) ||
           ((gNfcip.cfg.did == RFAL_NFCDEP_DID_NO) &&
            (nfcDepLen > RFAL_NFCDEP_DSL_RLS_LEN_NO_DID))) {
            nfcipLogI(" NFCIP(T) RLS wrong DID, ignoring \r\n");
            return ERR_BUSY;
        }

        nfcipTx(NFCIP_CMD_RLS_RES, resBuf, NULL, 0, 0, NFCIP_NO_FWT);

        gNfcip.state = NFCIP_ST_TARG_DEP_IDLE;
        return ERR_RELEASE_REQ;

    /*******************************************************************************/
    /*case NFCIP_CMD_PSL_REQ:              PSL must be handled in Activation only */
    /*case NFCIP_CMD_WUP_REQ:              WUP not in NFC Forum Digital 1.0       */
    default:

        /* Don't go to NFCIP_ST_TARG_DEP_IDLE state as it needs to ignore this    *
             * invalid frame, and keep waiting for more frames                        */

        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY; /* ERR_PROTO - Ignore bad frame */
    }

    /*******************************************************************************/

    rxPFB = gNfcip.rxBuf[rxMsgIt++]; /* Store rcvd PFB  */

    /*******************************************************************************/
    /* Check for valid PFB type                                                    */
    if(!(nfcip_PFBisSPDU(rxPFB) || nfcip_PFBisRPDU(rxPFB) || nfcip_PFBisIPDU(rxPFB))) {
        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY; /* ERR_PROTO - Ignore invalid PFB  */
    }

    /*******************************************************************************/
    if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
        if(!nfcip_PFBhasDID(rxPFB)) {
            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore bad/missing DID  */
        }
        if(gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.did) /* MISRA 13.5 */
        {
            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore bad/missing DID  */
        }
        optHdrLen++; /* Inc header optional field cnt*/
    } else if(nfcip_PFBhasDID(rxPFB)) /* DID not expected but rcv     */
    {
        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY; /* ERR_PROTO - Ignore unexpected DID  */
    } else {
        /* MISRA 15.7 - Empty else */
    }

    /*******************************************************************************/
    if(gNfcip.cfg.nad != RFAL_NFCDEP_NAD_NO) {
        if((gNfcip.rxBuf[rxMsgIt++] != gNfcip.cfg.did) || !nfcip_PFBhasDID(rxPFB)) {
            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore bad/missing DID  */
        }
        optHdrLen++; /* Inc header optional field cnt*/
    } else if(nfcip_PFBhasNAD(rxPFB)) /* NAD not expected but rcv */
    {
        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        return ERR_BUSY; /* ERR_PROTO - Ignore unexpected NAD  */
    } else {
        /* MISRA 15.7 - Empty else */
    }

    /*******************************************************************************/
    /* Process R-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisRPDU(rxPFB)) {
        nfcipLogD(" NFCIP(T) Rcvd R-PDU  \r\n");
        /*******************************************************************************/
        /* R ACK                                                                       */
        /*******************************************************************************/
        if(nfcip_PFBisRACK(rxPFB)) {
            nfcipLogI(" NFCIP(T) Rcvd ACK  \r\n");
            if(gNfcip.pni == nfcip_PBF_PNI(rxPFB)) {
                /* R-ACK while not performing chaining -> Protocol error */
                if(!gNfcip.isTxChaining) {
                    nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
                    return ERR_BUSY; /* ERR_PROTO - Ignore unexpected ACK  */
                }

                /* This block has been transmitted and acknowledged, perform RTOX until next data is provided  */

                /* Digital 1.1  16.12.4.7 - If ACK rcvd continue with chaining or an RTOX */
                nfcipTimerStart(
                    gNfcip.RTOXTimer,
                    nfcipRTOXAdjust(nfcipConv1FcToMs(rfalNfcDepWT2RWT(gNfcip.cfg.to))));
                gNfcip.state = NFCIP_ST_TARG_DEP_RTOX;

                return ERR_NONE; /* This block has been transmitted */
            }

            /* Digital 1.0 14.12.3.4 - If last send was ATN and rx PNI is minus 1 */
            else if(
                nfcip_PFBisSATN(gNfcip.lastPFB) &&
                (nfcip_PNIDec(gNfcip.pni) == nfcip_PBF_PNI(rxPFB))) {
                nfcipLogI(" NFCIP(T) wrong PNI, last was ATN reTx  \r\n");
                /* Spec says to leave current PNI as is, but will be Inc after Tx, remaining the same */
                gNfcip.pni = nfcip_PNIDec(gNfcip.pni);

                gNfcip.state = NFCIP_ST_TARG_DEP_TX;
                return ERR_BUSY;
            } else {
                /* MISRA 15.7 - Empty else */
            }
        }
        /*******************************************************************************/
        /* R NACK                                                                      */
        /*******************************************************************************/
        /* ISO 18092 12.6.1.3.3 When rcv NACK if PNI = prev PNI sent ->  reTx          */
        else if(nfcip_PFBisRNACK(rxPFB) && (nfcip_PNIDec(gNfcip.pni) == nfcip_PBF_PNI(rxPFB))) {
            nfcipLogI(" NFCIP(T) Rcvd NACK  \r\n");

            gNfcip.pni = nfcip_PNIDec(gNfcip.pni); /* Dec so that has the prev PNI */

            gNfcip.state = NFCIP_ST_TARG_DEP_TX;
            return ERR_BUSY;
        } else {
            nfcipLogI(" NFCIP(T) Unexpected R-PDU \r\n");

            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore unexpected R-PDU  */
        }
    }

    /*******************************************************************************/
    /* Process S-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisSPDU(rxPFB)) {
        nfcipLogD(" NFCIP(T) Rcvd S-PDU  \r\n");

        /*******************************************************************************/
        /* S ATN                                                                       */
        /*******************************************************************************/
        /* ISO 18092 12.6.3 Attention                                                  */
        if(nfcip_PFBisSATN(rxPFB)) /*    If is a S-ATN     */
        {
            nfcipLogI(" NFCIP(T) Rcvd ATN  curPNI: %d \r\n", gNfcip.pni);
            EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBSPDU_ATN(), 0));
            return ERR_BUSY;
        }

        /*******************************************************************************/
        /* S TO                                                                        */
        /*******************************************************************************/
        else if(nfcip_PFBisSTO(rxPFB)) /* If is a S-TO (RTOX)  */
        {
            if(nfcip_PFBisSTO(gNfcip.lastPFBnATN)) {
                nfcipLogI(" NFCIP(T) Rcvd TO  \r\n");

                /* Digital 1.1  16.8.4.6  RTOX value in RES different that in REQ -> Protocol Error */
                if(gNfcip.lastRTOX != gNfcip.rxBuf[rxMsgIt++]) {
                    nfcipLogI(" NFCIP(T) Mismatched RTOX value \r\n");

                    nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
                    return ERR_BUSY; /* ERR_PROTO - Ignore unexpected RTOX value  */
                }

                /* Clear waiting for RTOX Ack Flag */
                gNfcip.isWait4RTOX = false;

                /* Check if a Tx is already pending */
                if(gNfcip.isTxPending) {
                    nfcipLogW(" NFCIP(T) Tx pending, go immediately to TX \r\n");

                    gNfcip.state = NFCIP_ST_TARG_DEP_TX;
                    return ERR_BUSY;
                }

                /* Start RTOX timer and change to check state  */
                nfcipTimerStart(
                    gNfcip.RTOXTimer,
                    nfcipRTOXAdjust(
                        nfcipConv1FcToMs(gNfcip.lastRTOX * rfalNfcDepWT2RWT(gNfcip.cfg.to))));
                gNfcip.state = NFCIP_ST_TARG_DEP_RTOX;

                return ERR_BUSY;
            }
        } else {
            /* Unexpected S-PDU */
            nfcipLogI(
                " NFCIP(T) Unexpected S-PDU \r\n"); /*  PRQA S  2880 # MISRA 2.1 - Guard code to prevent unexpected behavior */

            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore unexpected S-PDU  */
        }
    }

    /*******************************************************************************/
    /* Process I-PDU                                                               */
    /*******************************************************************************/
    if(nfcip_PFBisIPDU(rxPFB)) {
        if(gNfcip.pni != nfcip_PBF_PNI(rxPFB)) {
            nfcipLogI(
                " NFCIP(T) Rcvd IPDU wrong PNI     curPNI: %d rxPNI: %d \r\n",
                gNfcip.pni,
                nfcip_PBF_PNI(rxPFB));

            /* Digital 1.1 16.12.3.4 - If last send was ATN and rx PNI is minus 1 */
            if(nfcip_PFBisSATN(gNfcip.lastPFB) &&
               (nfcip_PNIDec(gNfcip.pni) == nfcip_PBF_PNI(rxPFB))) {
                /* Spec says to leave current PNI as is, but will be Inc after Data Tx, remaining the same */
                gNfcip.pni = nfcip_PNIDec(gNfcip.pni);

                if(nfcip_PFBisIMI(rxPFB)) {
                    nfcipLogI(
                        " NFCIP(T) PNI = prevPNI && ATN before && chaining -> send ACK  \r\n");
                    EXIT_ON_ERR(
                        ret,
                        nfcipDEPControlMsg(nfcip_PFBRPDU_ACK(gNfcip.pni), gNfcip.rxBuf[rxMsgIt++]));

                    /* Digital 1.1 16.12.3.4 (...) leave the current PNI unchanged afterwards */
                    gNfcip.pni = nfcip_PNIInc(gNfcip.pni);
                } else {
                    nfcipLogI(" NFCIP(T) PNI = prevPNI && ATN before -> reTx last I-PDU  \r\n");
                    gNfcip.state = NFCIP_ST_TARG_DEP_TX;
                }

                return ERR_BUSY;
            }

            nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
            return ERR_BUSY; /* ERR_PROTO - Ignore bad PNI value  */
        }

        nfcipLogD(" NFCIP(T) Rcvd IPDU OK PNI: %d  \r\n", gNfcip.pni);

        /*******************************************************************************/
        /* Successful data exchange                                                    */
        /*******************************************************************************/
        *outActRxLen = ((uint16_t)nfcDepLen - RFAL_NFCDEP_DEP_HEADER - (uint16_t)optHdrLen);

        nfcipClearCounters();

        if((&gNfcip.rxBuf[gNfcip.rxBufPaylPos] !=
            &gNfcip.rxBuf[RFAL_NFCDEP_DEP_HEADER + optHdrLen]) &&
           (*outActRxLen > 0U)) {
            ST_MEMMOVE(
                &gNfcip.rxBuf[gNfcip.rxBufPaylPos],
                &gNfcip.rxBuf[RFAL_NFCDEP_DEP_HEADER + optHdrLen],
                *outActRxLen);
        }

        /*******************************************************************************/
        /* Check if Initiator is indicating chaining MI                                */
        /*******************************************************************************/
        if(nfcip_PFBisIMI(rxPFB)) {
            gNfcip.isRxChaining = true;
            *outIsChaining = true;

            nfcipLogD(" NFCIP(T) Rcvd IPDU OK w MI -> ACK \r\n");
            EXIT_ON_ERR(
                ret, nfcipDEPControlMsg(nfcip_PFBRPDU_ACK(gNfcip.pni), gNfcip.rxBuf[rxMsgIt++]));

            gNfcip.pni = nfcip_PNIInc(gNfcip.pni);

            return ERR_AGAIN; /* Send Again signalling to run again, but some chaining data has arrived*/
        } else {
            if(gNfcip.isRxChaining) {
                nfcipLogI(" NFCIP(T) Rcvd last IPDU chaining finished \r\n");
            }

            /*******************************************************************************/
            /* Reception done, send to DH and start RTOX timer                             */
            /*******************************************************************************/
            nfcipTimerStart(
                gNfcip.RTOXTimer,
                nfcipRTOXAdjust(nfcipConv1FcToMs(rfalNfcDepWT2RWT(gNfcip.cfg.to))));
            gNfcip.state = NFCIP_ST_TARG_DEP_RTOX;

            gNfcip.isRxChaining = false;
            ret = ERR_NONE; /* Data exchange done */
        }
    }
    return ret;
}

/*******************************************************************************/
static ReturnCode nfcipTx(
    rfalNfcDepCmd cmd,
    uint8_t* txBuf,
    uint8_t* paylBuf,
    uint16_t paylLen,
    uint8_t pfbData,
    uint32_t fwt) {
    uint16_t txBufIt;
    uint8_t* txBlock;
    uint8_t* payloadBuf;
    uint8_t pfb;

    if(txBuf == NULL) {
        return ERR_PARAM;
    }

    payloadBuf = paylBuf; /* MISRA 17.8: Use intermediate variable */

    if((paylLen == 0U) || (payloadBuf == NULL)) {
        payloadBuf = (uint8_t*)&txBuf
            [RFAL_NFCDEP_DEPREQ_HEADER_LEN]; /* If not a DEP (no Data) ensure enough space for header */
    }

    txBufIt = 0;
    pfb = pfbData; /* MISRA 17.8: Use intermediate variable */

    txBlock = payloadBuf; /* Point to beginning of the Data, and go backwards     */

    gNfcip.lastCmd = (uint8_t)cmd; /* Store last cmd sent    */
    gNfcip.lastPFB = NFCIP_PFB_INVALID; /* Reset last pfb sent    */

    /*******************************************************************************/
    /* Compute outgoing NFCIP message                                              */
    /*******************************************************************************/
    switch(cmd) {
    /*******************************************************************************/
    case NFCIP_CMD_ATR_RES:
    case NFCIP_CMD_ATR_REQ:

        rfalNfcDepSetNFCID(payloadBuf, gNfcip.cfg.nfcid, gNfcip.cfg.nfcidLen); /* NFCID */
        txBufIt += RFAL_NFCDEP_NFCID3_LEN;

        payloadBuf[txBufIt++] = gNfcip.cfg.did; /* DID   */
        payloadBuf[txBufIt++] = gNfcip.cfg.bs; /* BS    */
        payloadBuf[txBufIt++] = gNfcip.cfg.br; /* BR    */

        if(cmd == NFCIP_CMD_ATR_RES) {
            payloadBuf[txBufIt++] = gNfcip.cfg.to; /* ATR_RES[ TO ] */
        }

        if(gNfcip.cfg.gbLen > 0U) {
            payloadBuf[txBufIt++] = nfcip_PPwGB(gNfcip.cfg.lr); /* PP signalling GB  */
            ST_MEMCPY(
                &payloadBuf[txBufIt], gNfcip.cfg.gb, gNfcip.cfg.gbLen); /* set General Bytes */
            txBufIt += gNfcip.cfg.gbLen;
        } else {
            payloadBuf[txBufIt++] = rfalNfcDepLR2PP(gNfcip.cfg.lr); /* PP without GB     */
        }

        if((txBufIt + RFAL_NFCDEP_CMDTYPE_LEN + RFAL_NFCDEP_CMD_LEN) >
           RFAL_NFCDEP_ATRREQ_MAX_LEN) /* Check max ATR length (ATR_REQ = ATR_RES)*/
        {
            return ERR_PARAM;
        }
        break;

    /*******************************************************************************/
    case NFCIP_CMD_WUP_REQ: /* ISO 18092 - 12.5.2.1 */

        rfalNfcDepSetNFCID((payloadBuf), gNfcip.cfg.nfcid, gNfcip.cfg.nfcidLen); /* NFCID */
        txBufIt += RFAL_NFCDEP_NFCID3_LEN;

        *(--txBlock) = gNfcip.cfg.did; /* DID   */
        break;

    /*******************************************************************************/
    case NFCIP_CMD_WUP_RES: /* ISO 18092 - 12.5.2.2 */
    case NFCIP_CMD_PSL_REQ:
    case NFCIP_CMD_PSL_RES:

        *(--txBlock) = gNfcip.cfg.did; /* DID   */
        break;

    /*******************************************************************************/
    case NFCIP_CMD_RLS_REQ:
    case NFCIP_CMD_RLS_RES:
    case NFCIP_CMD_DSL_REQ:
    case NFCIP_CMD_DSL_RES:

        /* Digital 1.0 - 14.8.1.1 & 14.9.1.1 & 14.10.1.1 Only add DID if not 0 */
        if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
            *(--txBlock) = gNfcip.cfg.did; /* DID   */
        }
        break;

    /*******************************************************************************/
    case NFCIP_CMD_DEP_REQ:
    case NFCIP_CMD_DEP_RES:

        /* Compute optional PFB bits */
        if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
            pfb |= NFCIP_PFB_DID_BIT;
        }
        if(gNfcip.cfg.nad != RFAL_NFCDEP_NAD_NO) {
            pfb |= NFCIP_PFB_NAD_BIT;
        }
        if((gNfcip.isTxChaining) && (nfcip_PFBisIPDU(pfb))) {
            pfb |= NFCIP_PFB_MI_BIT;
        }

        /* Store PFB for future handling */
        gNfcip.lastPFB = pfb; /* store PFB sent */

        if(!nfcip_PFBisSATN(pfb)) {
            gNfcip.lastPFBnATN = pfb; /* store last PFB different then ATN */
        }

        /* Add NAD if it is to be supported */
        if(gNfcip.cfg.nad != RFAL_NFCDEP_NAD_NO) {
            *(--txBlock) = gNfcip.cfg.nad; /* NAD   */
        }

        /* Digital 1.0 - 14.8.1.1 & 14.8.1.1 Only add DID if not 0 */
        if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
            *(--txBlock) = gNfcip.cfg.did; /* DID   */
        }

        *(--txBlock) = pfb; /* PFB */

        /* NCI 1.0 - Check if Empty frames are allowed */
        if((paylLen == 0U) && nfcipIsEmptyDEPDisabled(gNfcip.cfg.oper) && nfcip_PFBisIPDU(pfb)) {
            return ERR_PARAM;
        }
        break;

    /*******************************************************************************/
    default:
        return ERR_PARAM;
    }

    /*******************************************************************************/
    /* Prepend Header                                                              */
    /*******************************************************************************/
    *(--txBlock) = (uint8_t)cmd; /* CMD     */
    *(--txBlock) = (uint8_t)(nfcipCmdIsReq(cmd) ? NFCIP_REQ : NFCIP_RES); /* CMDType */

    txBufIt +=
        paylLen +
        (uint16_t)((uint32_t)payloadBuf - (uint32_t)txBlock); /* Calculate overall buffer size */

    if(txBufIt > gNfcip.fsc) /* Check if msg length violates the maximum payload size FSC */
    {
        return ERR_NOTSUPP;
    }

    /*******************************************************************************/
    return nfcipDataTx(txBlock, txBufIt, fwt);
}

/*
 ******************************************************************************
 * GLOBAL FUNCTIONS
 ******************************************************************************
 */

/*******************************************************************************/
static void nfcipConfig(const rfalNfcDepConfigs* cfg) {
    if(cfg == NULL) {
        return;
    }

    ST_MEMCPY(&gNfcip.cfg, cfg, sizeof(rfalNfcDepConfigs)); /* Copy given config to local       */

    gNfcip.cfg.to =
        MIN(RFAL_NFCDEP_WT_TRG_MAX, gNfcip.cfg.to); /* Ensure proper WT value           */
    gNfcip.cfg.did = nfcip_DIDMax(gNfcip.cfg.did); /* Ensure proper DID value          */
    gNfcip.fsc = rfalNfcDepLR2FS(gNfcip.cfg.lr); /* Calculate FSC based on given LR  */

    gNfcip.state =
        ((gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) ? NFCIP_ST_TARG_WAIT_ATR :
                                                        NFCIP_ST_INIT_IDLE);
}

/*******************************************************************************/
static ReturnCode nfcipRun(uint16_t* outActRxLen, bool* outIsChaining) {
    ReturnCode ret;

    ret = ERR_SYNTAX;

    nfcipLogD(" NFCIP Run() state: %d \r\n", gNfcip.state);

    switch(gNfcip.state) {
    /*******************************************************************************/
    case NFCIP_ST_IDLE:
    case NFCIP_ST_INIT_DEP_IDLE:
    case NFCIP_ST_TARG_DEP_IDLE:
    case NFCIP_ST_TARG_DEP_SLEEP:
        return ERR_NONE;

    /*******************************************************************************/
    case NFCIP_ST_INIT_DEP_TX:

        nfcipLogD(" NFCIP(I) Tx PNI: %d txLen: %d \r\n", gNfcip.pni, gNfcip.txBufLen);
        ret = nfcipTx(
            NFCIP_CMD_DEP_REQ,
            gNfcip.txBuf,
            &gNfcip.txBuf[gNfcip.txBufPaylPos],
            gNfcip.txBufLen,
            nfcip_PFBIPDU(gNfcip.pni),
            (gNfcip.cfg.fwt + gNfcip.cfg.dFwt));

        switch(ret) {
        case ERR_NONE:
            gNfcip.state = NFCIP_ST_INIT_DEP_RX;
            break;

        case ERR_PARAM:
        default:
            gNfcip.state = NFCIP_ST_INIT_DEP_IDLE;
            return ret;
        }
        /* fall through */

    /*******************************************************************************/
    case NFCIP_ST_INIT_DEP_RX: /*  PRQA S 2003 # MISRA 16.3 - Intentional fall through */

        ret = nfcipDataRx(false);

        if(ret != ERR_BUSY) {
            ret = nfcipInitiatorHandleDEP(ret, *gNfcip.rxRcvdLen, outActRxLen, outIsChaining);
        }

        break;

    /*******************************************************************************/
    case NFCIP_ST_TARG_DEP_RTOX:

        if(!nfcipTimerisExpired(gNfcip.RTOXTimer)) /* Do nothing until RTOX timer has expired */
        {
            return ERR_BUSY;
        }

        /* If we cannot send a RTOX raise a Timeout error so that we do not   
             * hold the field On forever in AP2P                                  */
        if(nfcipIsRTOXReqDisabled(gNfcip.cfg.oper)) {
            /* We should reEnable Rx, and measure time between our field Off to 
                 * either report link loss or recover               #287          */
            nfcipLogI(" NFCIP(T) RTOX not sent due to config, NOT reenabling Rx \r\n");
            return ERR_TIMEOUT;
        }

        if(gNfcip.cntRTOXRetrys++ >
           RFAL_NFCDEP_MAX_RTOX_RETRYS) /* Check maximum consecutive RTOX requests */
        {
            return ERR_PROTO;
        }

        nfcipLogI(" NFCIP(T) RTOX sent \r\n");

        gNfcip.lastRTOX =
            nfcip_RTOXTargMax(gNfcip.cfg.to); /* Calculate requested RTOX value, and send it */
        EXIT_ON_ERR(ret, nfcipDEPControlMsg(nfcip_PFBSPDU_TO(), gNfcip.lastRTOX));

        /* Set waiting for RTOX Ack Flag */
        gNfcip.isWait4RTOX = true;

        gNfcip.state = NFCIP_ST_TARG_DEP_RX; /* Go back to Rx to process RTOX ack       */
        return ERR_BUSY;

    /*******************************************************************************/
    case NFCIP_ST_TARG_DEP_TX:

        nfcipLogD(" NFCIP(T) Tx PNI: %d txLen: %d \r\n", gNfcip.pni, gNfcip.txBufLen);
        ret = nfcipTx(
            NFCIP_CMD_DEP_RES,
            gNfcip.txBuf,
            &gNfcip.txBuf[gNfcip.txBufPaylPos],
            gNfcip.txBufLen,
            nfcip_PFBIPDU(gNfcip.pni),
            NFCIP_NO_FWT);

        /* Clear flags */
        gNfcip.isTxPending = false;
        gNfcip.isWait4RTOX = false;

        /* Digital 1.0 14.12.3.4 Increment the current PNI after Tx */
        gNfcip.pni = nfcip_PNIInc(gNfcip.pni);

        switch(ret) {
        case ERR_NONE:
            gNfcip.state = NFCIP_ST_TARG_DEP_RX; /* All OK, goto Rx state          */
            break;

        case ERR_PARAM:
        default:
            gNfcip.state = NFCIP_ST_TARG_DEP_IDLE; /* Upon Tx error, goto IDLE state */
            return ret;
        }
        /* fall through */

    /*******************************************************************************/
    case NFCIP_ST_TARG_DEP_RX: /*  PRQA S 2003 # MISRA 16.3 - Intentional fall through */

        if(gNfcip.isReqPending) /* if already has Data should be from a DEP from nfcipTargetHandleActivation()  */
        {
            nfcipLogD(" NFCIP(T) Skipping Rx Using DEP from Activation \r\n");

            gNfcip.isReqPending = false;
            ret = ERR_NONE;
        } else {
            ret = nfcipDataRx(false);
        }

        if(ret != ERR_BUSY) {
            ret = nfcipTargetHandleRX(ret, outActRxLen, outIsChaining);
        }

        break;

    /*******************************************************************************/
    default:
        /* MISRA 16.4: no empty default statement (a comment being enough) */
        break;
    }
    return ret;
}

/*******************************************************************************/
void rfalNfcDepSetDeactivatingCallback(rfalNfcDepDeactCallback pFunc) {
    gNfcip.isDeactivating = pFunc;
}

/*******************************************************************************/
void rfalNfcDepInitialize(void) {
    nfcipLogD(" NFCIP Ini() \r\n");

    gNfcip.state = NFCIP_ST_IDLE;
    gNfcip.isDeactivating = NULL;

    gNfcip.isTxPending = false;
    gNfcip.isWait4RTOX = false;
    gNfcip.isReqPending = false;

    gNfcip.cfg.oper =
        (RFAL_NFCDEP_OPER_FULL_MI_DIS | RFAL_NFCDEP_OPER_EMPTY_DEP_EN | RFAL_NFCDEP_OPER_ATN_EN |
         RFAL_NFCDEP_OPER_RTOX_REQ_EN);

    gNfcip.cfg.did = RFAL_NFCDEP_DID_NO;
    gNfcip.cfg.nad = RFAL_NFCDEP_NAD_NO;

    gNfcip.cfg.br = RFAL_NFCDEP_Bx_NO_HIGH_BR;
    gNfcip.cfg.bs = RFAL_NFCDEP_Bx_NO_HIGH_BR;

    gNfcip.cfg.lr = RFAL_NFCDEP_LR_254;
    gNfcip.fsc = rfalNfcDepLR2FS(gNfcip.cfg.lr);

    gNfcip.cfg.gbLen = 0;

    gNfcip.cfg.fwt = RFAL_NFCDEP_MAX_FWT;
    gNfcip.cfg.dFwt = RFAL_NFCDEP_MAX_FWT;

    gNfcip.pni = 0;

    /* Destroy any ongoing RTOX timer*/
    nfcipTimerDestroy(gNfcip.RTOXTimer);
    gNfcip.RTOXTimer = 0U;

    gNfcip.PDUTxPos = 0;
    gNfcip.PDURxPos = 0;
    gNfcip.PDUParam.rxLen = NULL;
    gNfcip.PDUParam.rxBuf = NULL;
    gNfcip.PDUParam.txBuf = NULL;

    nfcipClearCounters();
}

/*******************************************************************************/
static void nfcipSetDEPParams(const rfalNfcDepDEPParams* DEPParams) {
    nfcipLogD(" NFCIP SetDEP() txLen: %d \r\n", DEPParams->txBufLen);

    gNfcip.isTxChaining = DEPParams->txChaining;
    gNfcip.txBuf = DEPParams->txBuf;
    gNfcip.rxBuf = DEPParams->rxBuf;
    gNfcip.txBufLen = DEPParams->txBufLen;
    gNfcip.rxBufLen = DEPParams->rxBufLen;
    gNfcip.txBufPaylPos = DEPParams->txBufPaylPos;
    gNfcip.rxBufPaylPos = DEPParams->rxBufPaylPos;

    if(DEPParams->did != RFAL_NFCDEP_DID_KEEP) {
        gNfcip.cfg.did = nfcip_DIDMax(DEPParams->did);
    }

    gNfcip.cfg.fwt = DEPParams->fwt;
    gNfcip.cfg.dFwt = DEPParams->dFwt;
    gNfcip.fsc = DEPParams->fsc;

    if(gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) {
        /* If there's any data to be sent go for Tx */
        if(DEPParams->txBufLen > 0U) {
            /* Ensure that an RTOX Ack is not being expected at moment */
            if(!gNfcip.isWait4RTOX) {
                gNfcip.state = NFCIP_ST_TARG_DEP_TX;
                return;
            } else {
                /* If RTOX Ack is expected, signal a pending Tx to be transmitted right after */
                gNfcip.isTxPending = true;
                nfcipLogW(" NFCIP(T) Waiting RTOX, queueing outgoing DEP Block \r\n");
            }
        }

        /*Digital 1.0  14.12.4.1 In target mode the first PDU MUST be sent by the Initiator */
        gNfcip.state = NFCIP_ST_TARG_DEP_RX;
        return;
    }

    /* New data TxRx request clear previous error counters for consecutive TxRx without reseting communication/protocol layer*/
    nfcipClearCounters();

    gNfcip.state = NFCIP_ST_INIT_DEP_TX;
}

/*******************************************************************************/
bool rfalNfcDepTargetRcvdATR(void) {
    return (
        (gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) && nfcipIsTarget(gNfcip.state) &&
        (gNfcip.state > NFCIP_ST_TARG_WAIT_ATR));
}

/*******************************************************************************/
bool rfalNfcDepIsAtrReq(const uint8_t* buf, uint16_t bufLen, uint8_t* nfcid3) {
    uint8_t msgIt;

    msgIt = 0;

    if((bufLen < RFAL_NFCDEP_ATRREQ_MIN_LEN) || (bufLen > RFAL_NFCDEP_ATRREQ_MAX_LEN)) {
        return false;
    }

    if(buf[msgIt++] != NFCIP_REQ) {
        return false;
    }

    if(buf[msgIt++] != (uint8_t)NFCIP_CMD_ATR_REQ) {
        return false;
    }

    /* Output NFID3 if requested */
    if(nfcid3 != NULL) {
        ST_MEMCPY(nfcid3, &buf[RFAL_NFCDEP_ATR_REQ_NFCID3_POS], RFAL_NFCDEP_NFCID3_LEN);
    }

    return true;
}

/*******************************************************************************/
static ReturnCode nfcipTargetHandleActivation(rfalNfcDepDevice* nfcDepDev, uint8_t* outBRS) {
    ReturnCode ret;
    uint8_t msgIt;
    uint8_t txBuf[RFAL_NFCDEP_HEADER_PAD + NFCIP_PSLRES_LEN];

    /*******************************************************************************/
    /*  Check if we are in correct state                                           */
    /*******************************************************************************/
    if(gNfcip.state != NFCIP_ST_TARG_WAIT_ACTV) {
        return ERR_WRONG_STATE;
    }

    /*******************************************************************************/
    /*  Check required parameters                                                  */
    /*******************************************************************************/
    if(outBRS == NULL) {
        return ERR_PARAM;
    }

    /*******************************************************************************/
    /*  Wait and process incoming cmd (PSL / DEP)                                  */
    /*******************************************************************************/
    ret = nfcipDataRx(false);

    if(ret != ERR_NONE) {
        return ret;
    }

    msgIt = 0;
    *outBRS = RFAL_NFCDEP_BRS_MAINTAIN; /* set out BRS to be maintained */

    msgIt++; /* Skip LEN byte                */

    if(gNfcip.rxBuf[msgIt++] != NFCIP_REQ) {
        return ERR_PROTO;
    }

    if(gNfcip.rxBuf[msgIt] == (uint8_t)NFCIP_CMD_PSL_REQ) {
        msgIt++;

        if(gNfcip.rxBuf[msgIt++] != gNfcip.cfg.did) /* Checking DID                 */
        {
            return ERR_PROTO;
        }

        nfcipLogI(" NFCIP(T) PSL REQ rcvd \r\n");

        *outBRS = gNfcip.rxBuf[msgIt++]; /* assign output BRS value      */

        /* Store FSL(LR) and update current config */
        gNfcip.cfg.lr = (gNfcip.rxBuf[msgIt++] & RFAL_NFCDEP_LR_VAL_MASK);
        gNfcip.fsc = rfalNfcDepLR2FS(gNfcip.cfg.lr);

        /*******************************************************************************/
        /* Update NFC-DDE Device info */
        if(nfcDepDev != NULL) {
            /* Update Bitrate info */
            /* PRQA S 4342 2 # MISRA 10.5 - Layout of enum rfalBitRate and definition of rfalNfcDepBRS2DSI guarantee no invalid enum values to be created */
            nfcDepDev->info.DSI = (rfalBitRate)rfalNfcDepBRS2DSI(
                *outBRS); /* DSI codes the bit rate from Initiator to Target */
            nfcDepDev->info.DRI = (rfalBitRate)rfalNfcDepBRS2DRI(
                *outBRS); /* DRI codes the bit rate from Target to Initiator */

            /* Update Length Reduction and Frame Size */
            nfcDepDev->info.LR = gNfcip.cfg.lr;
            nfcDepDev->info.FS = gNfcip.fsc;

            /* Update PPi byte */
            nfcDepDev->activation.Initiator.ATR_REQ.PPi &= ~RFAL_NFCDEP_PP_LR_MASK;
            nfcDepDev->activation.Initiator.ATR_REQ.PPi |= rfalNfcDepLR2PP(gNfcip.cfg.lr);
        }

        rfalSetBitRate(RFAL_BR_KEEP, gNfcip.nfcDepDev->info.DSI);

        EXIT_ON_ERR(ret, nfcipTx(NFCIP_CMD_PSL_RES, txBuf, NULL, 0, 0, NFCIP_NO_FWT));
    } else {
        if(gNfcip.rxBuf[msgIt] == (uint8_t)NFCIP_CMD_DEP_REQ) {
            msgIt++;

            /*******************************************************************************/
            /* Digital 1.0 14.12.3.1 PNI must be initialized to 0 */
            if(nfcip_PBF_PNI(gNfcip.rxBuf[msgIt]) != 0U) {
                return ERR_PROTO;
            }

            /*******************************************************************************/
            /* Digital 1.0 14.8.2.1  check if DID is expected and match -> Protocol Error  */
            if(nfcip_PFBhasDID(gNfcip.rxBuf[msgIt])) {
                if(gNfcip.rxBuf[++msgIt] != gNfcip.cfg.did) {
                    return ERR_PROTO;
                }
            } else if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) /* DID expected but not rcv */
            {
                return ERR_PROTO;
            } else {
                /* MISRA 15.7 - Empty else */
            }
        }

        /* Signal Request pending to be digested on normal Handling (DEP_REQ, DSL_REQ, RLS_REQ) */
        gNfcip.isReqPending = true;
    }

    gNfcip.state = NFCIP_ST_TARG_DEP_RX;
    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode
    rfalNfcDepATR(const rfalNfcDepAtrParam* param, rfalNfcDepAtrRes* atrRes, uint8_t* atrResLen) {
    ReturnCode ret;
    rfalNfcDepConfigs cfg;
    uint16_t rxLen;
    uint8_t msgIt;
    uint8_t txBuf[RFAL_NFCDEP_ATRREQ_MAX_LEN];
    uint8_t rxBuf[NFCIP_ATRRES_BUF_LEN];

    if((param == NULL) || (atrRes == NULL) || (atrResLen == NULL)) {
        return ERR_PARAM;
    }

    /*******************************************************************************/
    /* Configure NFC-DEP layer                                                     */
    /*******************************************************************************/

    cfg.did = param->DID;
    cfg.nad = param->NAD;
    cfg.fwt = RFAL_NFCDEP_MAX_FWT;
    cfg.dFwt = RFAL_NFCDEP_MAX_FWT;
    cfg.br = param->BR;
    cfg.bs = param->BS;
    cfg.lr = param->LR;
    cfg.to = RFAL_NFCDEP_WT_TRG_MAX; /* Not used in Initiator mode */

    cfg.gbLen = param->GBLen;
    if(cfg.gbLen > 0U) /* MISRA 21.18 */
    {
        ST_MEMCPY(cfg.gb, param->GB, cfg.gbLen);
    }

    cfg.nfcidLen = param->nfcidLen;
    if(cfg.nfcidLen > 0U) /* MISRA 21.18 */
    {
        ST_MEMCPY(cfg.nfcid, param->nfcid, cfg.nfcidLen);
    }

    cfg.role = RFAL_NFCDEP_ROLE_INITIATOR;
    cfg.oper = param->operParam;
    cfg.commMode = param->commMode;

    rfalNfcDepInitialize();
    nfcipConfig(&cfg);

    /*******************************************************************************/
    /* Send ATR_REQ                                                                */
    /*******************************************************************************/

    EXIT_ON_ERR(
        ret,
        nfcipTxRx(
            NFCIP_CMD_ATR_REQ,
            txBuf,
            nfcipRWTActivation(),
            NULL,
            0,
            rxBuf,
            NFCIP_ATRRES_BUF_LEN,
            &rxLen));

    /*******************************************************************************/
    /* ATR sent, check response                                                    */
    /*******************************************************************************/
    msgIt = 0;
    rxLen = ((uint16_t)rxBuf[msgIt++] - RFAL_NFCDEP_LEN_LEN); /* use LEN byte             */

    if((rxLen < RFAL_NFCDEP_ATRRES_MIN_LEN) ||
       (rxLen > RFAL_NFCDEP_ATRRES_MAX_LEN)) /* Checking length: ATR_RES */
    {
        return ERR_PROTO;
    }

    if(rxBuf[msgIt++] != NFCIP_RES) /* Checking if is a response*/
    {
        return ERR_PROTO;
    }

    if(rxBuf[msgIt++] != (uint8_t)NFCIP_CMD_ATR_RES) /* Checking if is a ATR RES */
    {
        return ERR_PROTO;
    }

    ST_MEMCPY((uint8_t*)atrRes, (rxBuf + RFAL_NFCDEP_LEN_LEN), rxLen);
    *atrResLen = (uint8_t)rxLen;

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepPSL(uint8_t BRS, uint8_t FSL) {
    ReturnCode ret;
    uint16_t rxLen;
    uint8_t msgIt;
    uint8_t txBuf[NFCIP_PSLREQ_LEN + NFCIP_PSLPAY_LEN];
    uint8_t rxBuf[NFCIP_PSLRES_LEN];

    msgIt = NFCIP_PSLREQ_LEN;

    txBuf[msgIt++] = BRS;
    txBuf[msgIt++] = FSL;

    /*******************************************************************************/
    /* Send PSL REQ and wait for response                                          */
    /*******************************************************************************/
    EXIT_ON_ERR(
        ret,
        nfcipTxRx(
            NFCIP_CMD_PSL_REQ,
            txBuf,
            nfcipRWTActivation(),
            &txBuf[NFCIP_PSLREQ_LEN],
            (msgIt - NFCIP_PSLREQ_LEN),
            rxBuf,
            NFCIP_PSLRES_LEN,
            &rxLen));

    /*******************************************************************************/
    /* PSL sent, check response                                                    */
    /*******************************************************************************/
    msgIt = 0;
    rxLen = (uint16_t)(rxBuf[msgIt++]); /* use LEN byte                   */

    if(rxLen < NFCIP_PSLRES_LEN) /* Checking length: LEN + RLS_RES */
    {
        return ERR_PROTO;
    }

    if(rxBuf[msgIt++] != NFCIP_RES) /* Checking if is a response      */
    {
        return ERR_PROTO;
    }

    if(rxBuf[msgIt++] != (uint8_t)NFCIP_CMD_PSL_RES) /* Checking if is a PSL RES       */
    {
        return ERR_PROTO;
    }

    if(rxBuf[msgIt++] != gNfcip.cfg.did) /* Checking DID                   */
    {
        return ERR_PROTO;
    }

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepDSL(void) {
    ReturnCode ret;
    uint8_t txBuf[RFAL_NFCDEP_HEADER_PAD + NFCIP_DSLREQ_LEN];
    uint8_t rxBuf[NFCIP_DSLRES_LEN];
    uint8_t rxMsgIt;
    uint16_t rxLen = 0;

    if(gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) {
        return ERR_NONE; /* Target has no deselect procedure */
    }

    /* Repeating a DSL REQ is optional, not doing it */
    EXIT_ON_ERR(
        ret,
        nfcipTxRx(
            NFCIP_CMD_DSL_REQ,
            txBuf,
            nfcipRWTActivation(),
            NULL,
            0,
            rxBuf,
            (uint16_t)sizeof(rxBuf),
            &rxLen));

    /*******************************************************************************/
    rxMsgIt = 0;

    if(rxBuf[rxMsgIt++] < NFCIP_DSLRES_MIN) /* Checking length: LEN + DSL_RES */
    {
        return ERR_PROTO;
    }

    if(rxBuf[rxMsgIt++] != NFCIP_RES) /* Checking if is a response      */
    {
        return ERR_PROTO;
    }

    if(rxBuf[rxMsgIt++] != (uint8_t)NFCIP_CMD_DSL_RES) /* Checking if is DSL RES          */
    {
        return ERR_PROTO;
    }

    if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
        if(rxBuf[rxMsgIt++] != gNfcip.cfg.did) {
            return ERR_PROTO;
        }
    }

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepRLS(void) {
    ReturnCode ret;
    uint8_t txBuf[RFAL_NFCDEP_HEADER_PAD + NFCIP_RLSREQ_LEN];
    uint8_t rxBuf[NFCIP_RLSRES_LEN];
    uint8_t rxMsgIt;
    uint16_t rxLen = 0;

    if(gNfcip.cfg.role == RFAL_NFCDEP_ROLE_TARGET) /* Target has no release procedure */
    {
        return ERR_NONE;
    }

    /* Repeating a RLS REQ is optional, not doing it */
    EXIT_ON_ERR(
        ret,
        nfcipTxRx(
            NFCIP_CMD_RLS_REQ,
            txBuf,
            nfcipRWTActivation(),
            NULL,
            0,
            rxBuf,
            (uint16_t)sizeof(rxBuf),
            &rxLen));

    /*******************************************************************************/
    rxMsgIt = 0;

    if(rxBuf[rxMsgIt++] < NFCIP_RLSRES_MIN) /* Checking length: LEN + RLS_RES */
    {
        return ERR_PROTO;
    }

    if(rxBuf[rxMsgIt++] != NFCIP_RES) /* Checking if is a response      */
    {
        return ERR_PROTO;
    }

    if(rxBuf[rxMsgIt++] != (uint8_t)NFCIP_CMD_RLS_RES) /* Checking if is RLS RES         */
    {
        return ERR_PROTO;
    }

    if(gNfcip.cfg.did != RFAL_NFCDEP_DID_NO) {
        if(rxBuf[rxMsgIt++] != gNfcip.cfg.did) {
            return ERR_PROTO;
        }
    }

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepInitiatorHandleActivation(
    rfalNfcDepAtrParam* param,
    rfalBitRate desiredBR,
    rfalNfcDepDevice* nfcDepDev) {
    ReturnCode ret;
    uint8_t maxRetyrs;
    uint8_t PSL_BRS;
    uint8_t PSL_FSL;
    bool sendPSL;

    if((param == NULL) || (nfcDepDev == NULL)) {
        return ERR_PARAM;
    }

    param->NAD = RFAL_NFCDEP_NAD_NO; /* Digital 1.1  16.6.2.9  Initiator SHALL NOT use NAD */
    maxRetyrs = NFCIP_ATR_RETRY_MAX;

    /*******************************************************************************/
    /* Send ATR REQ and wait for response                                          */
    /*******************************************************************************/
    do { /* Upon transmission error ATR REQ should be retried */

        ret = rfalNfcDepATR(
            param,
            &nfcDepDev->activation.Target.ATR_RES,
            &nfcDepDev->activation.Target.ATR_RESLen);

        if(nfcipIsTransmissionError(ret)) {
            continue;
        }
        break;
    } while((maxRetyrs--) != 0U);

    if(ret != ERR_NONE) {
        return ret;
    }

    /*******************************************************************************/
    /* Compute NFC-DEP device with ATR_RES                                         */
    /*******************************************************************************/
    nfcDepDev->info.GBLen = (nfcDepDev->activation.Target.ATR_RESLen - RFAL_NFCDEP_ATRRES_MIN_LEN);
    nfcDepDev->info.DID = nfcDepDev->activation.Target.ATR_RES.DID;
    nfcDepDev->info.NAD =
        RFAL_NFCDEP_NAD_NO; /* Digital 1.1  16.6.3.11 Initiator SHALL ignore b1 of PPt */
    nfcDepDev->info.LR = rfalNfcDepPP2LR(nfcDepDev->activation.Target.ATR_RES.PPt);
    nfcDepDev->info.FS = rfalNfcDepLR2FS(nfcDepDev->info.LR);
    nfcDepDev->info.WT = (nfcDepDev->activation.Target.ATR_RES.TO & RFAL_NFCDEP_WT_MASK);
    nfcDepDev->info.FWT = rfalNfcDepCalculateRWT(nfcDepDev->info.WT);
    nfcDepDev->info.dFWT = RFAL_NFCDEP_WT_DELTA;

    rfalGetBitRate(&nfcDepDev->info.DSI, &nfcDepDev->info.DRI);

    /*******************************************************************************/
    /* Check if a PSL needs to be sent                                                */
    /*******************************************************************************/
    sendPSL = false;
    PSL_BRS = rfalNfcDepDx2BRS(
        nfcDepDev->info.DSI); /* Set current bit rate divisor on both directions  */
    PSL_FSL = nfcDepDev->info.LR; /* Set current Frame Size                           */

    /* Activity 1.0  9.4.4.15 & 9.4.6.3   NFC-DEP Activation PSL
    *  Activity 2.0  9.4.4.17 & 9.4.6.6   NFC-DEP Activation PSL
    *     
    *  PSL_REQ shall only be sent if desired bit rate is different from current (Activity 1.0)
    *  PSL_REQ shall be sent to update LR or bit rate  (Activity 2.0)
    * */

#if 0 /* PSL due to LR is disabled, can be enabled if desired*/
    /*******************************************************************************/
    /* Check Frame Size                                                            */
    /*******************************************************************************/
    if( gNfcip.cfg.lr < nfcDepDev->info.LR )  /* If our Length reduction is smaller */   
    {
        sendPSL = true;
        
        nfcDepDev->info.LR   = MIN( nfcDepDev->info.LR, gNfcip.cfg.lr );
        
        gNfcip.cfg.lr = nfcDepDev->info.LR;                /* Update nfcip LR  to be used */
        gNfcip.fsc    = rfalNfcDepLR2FS( gNfcip.cfg.lr );  /* Update nfcip FSC to be used */     
        
        PSL_FSL       = gNfcip.cfg.lr;                     /* Set LR to be sent           */
        
        nfcipLogI( " NFCIP(I) Frame Size differ, PSL new fsc: %d \r\n", gNfcip.fsc );
    }
#endif

    /*******************************************************************************/
    /* Check Baud rates                                                            */
    /*******************************************************************************/
    if((nfcDepDev->info.DSI != desiredBR) &&
       (desiredBR != RFAL_BR_KEEP)) /* if desired BR is different    */
    {
        if(nfcipDxIsSupported(
               (uint8_t)desiredBR,
               nfcDepDev->activation.Target.ATR_RES.BRt,
               nfcDepDev->activation.Target.ATR_RES
                   .BSt)) /* if desired BR is supported     */ /* MISRA 13.5 */
        {
            sendPSL = true;
            PSL_BRS = rfalNfcDepDx2BRS(desiredBR);

            nfcipLogI(" NFCIP(I) BR differ, PSL BR: 0x%02X \r\n", PSL_BRS);
        }
    }

    /*******************************************************************************/
    if(sendPSL) {
        /*******************************************************************************/
        /* Send PSL REQ and wait for response                                          */
        /*******************************************************************************/
        EXIT_ON_ERR(ret, rfalNfcDepPSL(PSL_BRS, PSL_FSL));

        /* Check if bit rate has been changed */
        if(nfcDepDev->info.DSI != desiredBR) {
            /* Check if device was in Passive NFC-A and went to higher bit rates, use NFC-F */
            if((nfcDepDev->info.DSI == RFAL_BR_106) &&
               (gNfcip.cfg.commMode == RFAL_NFCDEP_COMM_PASSIVE)) {
#if RFAL_FEATURE_NFCF
                /* If Passive initialize NFC-F module */
                rfalNfcfPollerInitialize(desiredBR);
#else /* RFAL_FEATURE_NFCF */
                return ERR_NOTSUPP;
#endif /* RFAL_FEATURE_NFCF */
            }

            nfcDepDev->info.DRI = desiredBR; /* DSI Bit Rate coding from Initiator  to Target  */
            nfcDepDev->info.DSI = desiredBR; /* DRI Bit Rate coding from Target to Initiator   */

            rfalSetBitRate(nfcDepDev->info.DSI, nfcDepDev->info.DRI);
        }

        return ERR_NONE; /* PSL has been sent    */
    }

    return ERR_NONE; /* No PSL has been sent */
}

/*******************************************************************************/
uint32_t rfalNfcDepCalculateRWT(uint8_t wt) {
    /* Digital 1.0  14.6.3.8  &  Digital 1.1  16.6.3.9     */
    /* Digital 1.1  16.6.3.9 treat all RFU values as WT=14 */
    uint8_t responseWaitTime = MIN(RFAL_NFCDEP_WT_INI_MAX, wt);

    return (uint32_t)rfalNfcDepWT2RWT(responseWaitTime);
}

/*******************************************************************************/
static ReturnCode nfcipDataTx(uint8_t* txBuf, uint16_t txBufLen, uint32_t fwt) {
    return rfalTransceiveBlockingTx(
        txBuf,
        txBufLen,
        gNfcip.rxBuf,
        gNfcip.rxBufLen,
        gNfcip.rxRcvdLen,
        (RFAL_TXRX_FLAGS_DEFAULT | (uint32_t)RFAL_TXRX_FLAGS_NFCIP1_ON),
        ((fwt == NFCIP_NO_FWT) ? RFAL_FWT_NONE : fwt));
}

/*******************************************************************************/
static ReturnCode nfcipDataRx(bool blocking) {
    ReturnCode ret;

    /* Perform Rx either blocking or non-blocking */
    if(blocking) {
        ret = rfalTransceiveBlockingRx();
    } else {
        ret = rfalGetTransceiveStatus();
    }

    if(ret != ERR_BUSY) {
        if(gNfcip.rxRcvdLen != NULL) {
            (*gNfcip.rxRcvdLen) = rfalConvBitsToBytes(*gNfcip.rxRcvdLen);

            if((ret == ERR_NONE) && (gNfcip.rxBuf != NULL)) {
                /* Digital 1.1  16.4.1.3 - Length byte LEN SHALL have a value between 3 and 255 -> otherwise treat as Transmission Error *
                 *                       - Ensure that actual received and frame length do match, otherwise treat as Transmission error  */
                if((*gNfcip.rxRcvdLen != (uint16_t)*gNfcip.rxBuf) ||
                   (*gNfcip.rxRcvdLen < RFAL_NFCDEP_LEN_MIN) ||
                   (*gNfcip.rxRcvdLen > RFAL_NFCDEP_LEN_MAX)) {
                    return ERR_FRAMING;
                }
            }
        }
    }

    return ret;
}

/*******************************************************************************/
ReturnCode rfalNfcDepListenStartActivation(
    const rfalNfcDepTargetParam* param,
    const uint8_t* atrReq,
    uint16_t atrReqLength,
    rfalNfcDepListenActvParam rxParam) {
    ReturnCode ret;
    rfalNfcDepConfigs cfg;

    if((param == NULL) || (atrReq == NULL) || (rxParam.rxLen == NULL)) {
        return ERR_PARAM;
    }

    /*******************************************************************************/
    /*  Check whether is a valid ATR_REQ Compute NFC-DEP device                    */
    if(!rfalNfcDepIsAtrReq(atrReq, atrReqLength, NULL)) {
        return ERR_PARAM;
    }

    rxParam.nfcDepDev->activation.Initiator.ATR_REQLen =
        (uint8_t)atrReqLength; /* nfcipIsAtrReq() is already checking Min and Max buffer lengths */
    if(atrReqLength > 0U) /* MISRA 21.18 */
    {
        ST_MEMCPY(
            (uint8_t*)&rxParam.nfcDepDev->activation.Initiator.ATR_REQ, atrReq, atrReqLength);
    }

    rxParam.nfcDepDev->info.GBLen = (uint8_t)(atrReqLength - RFAL_NFCDEP_ATRREQ_MIN_LEN);
    rxParam.nfcDepDev->info.DID = rxParam.nfcDepDev->activation.Initiator.ATR_REQ.DID;
    rxParam.nfcDepDev->info.NAD =
        RFAL_NFCDEP_NAD_NO; /* Digital 1.1  16.6.2.9  Initiator SHALL NOT use NAD */
    rxParam.nfcDepDev->info.LR =
        rfalNfcDepPP2LR(rxParam.nfcDepDev->activation.Initiator.ATR_REQ.PPi);
    rxParam.nfcDepDev->info.FS = rfalNfcDepLR2FS(rxParam.nfcDepDev->info.LR);
    rxParam.nfcDepDev->info.WT = 0;
    rxParam.nfcDepDev->info.FWT = NFCIP_NO_FWT;
    rxParam.nfcDepDev->info.dFWT = NFCIP_NO_FWT;

    rfalGetBitRate(&rxParam.nfcDepDev->info.DSI, &rxParam.nfcDepDev->info.DRI);

    /* Store Device Info location, updated upon a PSL  */
    gNfcip.nfcDepDev = rxParam.nfcDepDev;

    /*******************************************************************************/
    cfg.did = rxParam.nfcDepDev->activation.Initiator.ATR_REQ.DID;
    cfg.nad = RFAL_NFCDEP_NAD_NO;

    cfg.fwt = RFAL_NFCDEP_MAX_FWT;
    cfg.dFwt = RFAL_NFCDEP_MAX_FWT;

    cfg.br = param->brt;
    cfg.bs = param->bst;

    cfg.lr = rfalNfcDepPP2LR(param->ppt);

    cfg.gbLen = param->GBtLen;
    if(cfg.gbLen > 0U) /* MISRA 21.18 */
    {
        ST_MEMCPY(cfg.gb, param->GBt, cfg.gbLen);
    }

    cfg.nfcidLen = RFAL_NFCDEP_NFCID3_LEN;
    ST_MEMCPY(cfg.nfcid, param->nfcid3, RFAL_NFCDEP_NFCID3_LEN);

    cfg.to = param->to;

    cfg.role = RFAL_NFCDEP_ROLE_TARGET;
    cfg.oper = param->operParam;
    cfg.commMode = param->commMode;

    rfalNfcDepInitialize();
    nfcipConfig(&cfg);

    /*******************************************************************************/
    /*  Reply with ATR RES to Initiator                                            */
    /*******************************************************************************/
    gNfcip.rxBuf = (uint8_t*)rxParam.rxBuf;
    gNfcip.rxBufLen = sizeof(rfalNfcDepBufFormat);
    gNfcip.rxRcvdLen = rxParam.rxLen;
    gNfcip.rxBufPaylPos = RFAL_NFCDEP_DEPREQ_HEADER_LEN;
    gNfcip.isChaining = rxParam.isRxChaining;
    gNfcip.txBufPaylPos = RFAL_NFCDEP_DEPREQ_HEADER_LEN;

    EXIT_ON_ERR(ret, nfcipTx(NFCIP_CMD_ATR_RES, (uint8_t*)gNfcip.rxBuf, NULL, 0, 0, NFCIP_NO_FWT));

    gNfcip.state = NFCIP_ST_TARG_WAIT_ACTV;

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepListenGetActivationStatus(void) {
    ReturnCode err;
    uint8_t BRS;

    BRS = RFAL_NFCDEP_BRS_MAINTAIN;

    err = nfcipTargetHandleActivation(gNfcip.nfcDepDev, &BRS);

    switch(err) {
    case ERR_NONE:

        if(BRS != RFAL_NFCDEP_BRS_MAINTAIN) {
            /* DSI codes the bit rate from Initiator to Target */
            /* DRI codes the bit rate from Target to Initiator */

            if(gNfcip.cfg.commMode == RFAL_NFCDEP_COMM_ACTIVE) {
                EXIT_ON_ERR(
                    err,
                    rfalSetMode(
                        RFAL_MODE_LISTEN_ACTIVE_P2P,
                        gNfcip.nfcDepDev->info.DRI,
                        gNfcip.nfcDepDev->info.DSI));
            } else {
                EXIT_ON_ERR(
                    err,
                    rfalSetMode(
                        ((RFAL_BR_106 == gNfcip.nfcDepDev->info.DRI) ? RFAL_MODE_LISTEN_NFCA :
                                                                       RFAL_MODE_LISTEN_NFCF),
                        gNfcip.nfcDepDev->info.DRI,
                        gNfcip.nfcDepDev->info.DSI));
            }
        }
        break;

    case ERR_BUSY:
        // do nothing
        break;

    case ERR_PROTO:
    default:
        // re-enable receiving of data
        nfcDepReEnableRx(gNfcip.rxBuf, gNfcip.rxBufLen, gNfcip.rxRcvdLen);
        break;
    }

    return err;
}

/*******************************************************************************/
ReturnCode rfalNfcDepStartTransceive(const rfalNfcDepTxRxParam* param) {
    rfalNfcDepDEPParams nfcDepParams;

    nfcDepParams.txBuf = (uint8_t*)param->txBuf;
    nfcDepParams.txBufLen = param->txBufLen;
    nfcDepParams.txChaining = param->isTxChaining;
    nfcDepParams.txBufPaylPos =
        RFAL_NFCDEP_DEPREQ_HEADER_LEN; /* position in txBuf where actual outgoing data is located */
    nfcDepParams.did = RFAL_NFCDEP_DID_KEEP;
    nfcDepParams.rxBufPaylPos = RFAL_NFCDEP_DEPREQ_HEADER_LEN;
    nfcDepParams.rxBuf = (uint8_t*)param->rxBuf;
    nfcDepParams.rxBufLen = sizeof(rfalNfcDepBufFormat);
    nfcDepParams.fsc = param->FSx;
    nfcDepParams.fwt = param->FWT;
    nfcDepParams.dFwt = param->dFWT;

    gNfcip.rxRcvdLen = param->rxLen;
    gNfcip.isChaining = param->isRxChaining;

    nfcipSetDEPParams(&nfcDepParams);

    return ERR_NONE;
}

/*******************************************************************************/
ReturnCode rfalNfcDepGetTransceiveStatus(void) {
    return nfcipRun(gNfcip.rxRcvdLen, gNfcip.isChaining);
}

/*******************************************************************************/
static void rfalNfcDepPdu2BLockParam(
    rfalNfcDepPduTxRxParam pduParam,
    rfalNfcDepTxRxParam* blockParam,
    uint16_t txPos,
    uint16_t rxPos) {
    uint16_t maxInfLen;

    NO_WARNING(rxPos); /* Keep this param for future use */

    blockParam->DID = pduParam.DID;
    blockParam->FSx = pduParam.FSx;
    blockParam->FWT = pduParam.FWT;
    blockParam->dFWT = pduParam.dFWT;

    /* Calculate max INF/Payload to be sent to other device */
    maxInfLen = (blockParam->FSx - (RFAL_NFCDEP_HEADER + RFAL_NFCDEP_DEP_PFB_LEN));
    maxInfLen += ((blockParam->DID != RFAL_NFCDEP_DID_NO) ? RFAL_NFCDEP_DID_LEN : 0U);

    if((pduParam.txBufLen - txPos) > maxInfLen) {
        blockParam->isTxChaining = true;
        blockParam->txBufLen = maxInfLen;
    } else {
        blockParam->isTxChaining = false;
        blockParam->txBufLen = (pduParam.txBufLen - txPos);
    }

    /* TxBuf is moved to the beginning for every Block */
    blockParam->txBuf =
        (rfalNfcDepBufFormat*)pduParam
            .txBuf; /*  PRQA S 0310 # MISRA 11.3 - Intentional safe cast to avoiding large buffer duplication */
    blockParam->rxBuf =
        pduParam
            .tmpBuf; /* Simply using the pdu buffer is not possible because of current ACK handling */
    blockParam->isRxChaining = &gNfcip.isPDURxChaining;
    blockParam->rxLen = pduParam.rxLen;
}

/*******************************************************************************/
ReturnCode rfalNfcDepStartPduTransceive(rfalNfcDepPduTxRxParam param) {
    rfalNfcDepTxRxParam txRxParam;

    /* Initialize and store APDU context */
    gNfcip.PDUParam = param;
    gNfcip.PDUTxPos = 0;
    gNfcip.PDURxPos = 0;

    /* Convert PDU TxRxParams to Block TxRxParams */
    rfalNfcDepPdu2BLockParam(gNfcip.PDUParam, &txRxParam, gNfcip.PDUTxPos, gNfcip.PDURxPos);

    return rfalNfcDepStartTransceive(&txRxParam);
}

/*******************************************************************************/
ReturnCode rfalNfcDepGetPduTransceiveStatus(void) {
    ReturnCode ret;
    rfalNfcDepTxRxParam txRxParam;

    ret = rfalNfcDepGetTransceiveStatus();
    switch(ret) {
    /*******************************************************************************/
    case ERR_NONE:

        /* Check if we are still doing chaining on Tx */
        if(gNfcip.isTxChaining) {
            /* Add already Tx bytes */
            gNfcip.PDUTxPos += gNfcip.txBufLen;

            /* Convert APDU TxRxParams to I-Block TxRxParams */
            rfalNfcDepPdu2BLockParam(
                gNfcip.PDUParam, &txRxParam, gNfcip.PDUTxPos, gNfcip.PDURxPos);

            if(txRxParam.txBufLen > 0U) /* MISRA 21.18 */
            {
                /* Move next Block to beginning of APDU Tx buffer */
                ST_MEMCPY(
                    gNfcip.PDUParam.txBuf->pdu,
                    &gNfcip.PDUParam.txBuf->pdu[gNfcip.PDUTxPos],
                    txRxParam.txBufLen);
            }

            EXIT_ON_ERR(ret, rfalNfcDepStartTransceive(&txRxParam));
            return ERR_BUSY;
        }

        /* PDU TxRx is done */
        /* fall through */

    /*******************************************************************************/
    case ERR_AGAIN: /*  PRQA S 2003 # MISRA 16.3 - Intentional fall through */

        /* Check if no PDU transceive has been started before (data from rfalNfcDepListenStartActivation) */
        if(gNfcip.PDUParam.rxLen == NULL) {
            /* In Listen mode first chained packet cannot be retrieved via APDU interface */
            if(ret == ERR_AGAIN) {
                return ERR_NOTSUPP;
            }

            /* TxRx is complete and full data is already available */
            return ERR_NONE;
        }

        if((*gNfcip.PDUParam.rxLen) > 0U) /* MISRA 21.18 */
        {
            /* Ensure that data in tmpBuf still fits into PDU buffer */
            if((uint16_t)((uint16_t)gNfcip.PDURxPos + (*gNfcip.PDUParam.rxLen)) >
               RFAL_FEATURE_NFC_DEP_PDU_MAX_LEN) {
                return ERR_NOMEM;
            }

            /* Copy chained packet from tmp buffer to PDU buffer */
            ST_MEMCPY(
                &gNfcip.PDUParam.rxBuf->pdu[gNfcip.PDURxPos],
                gNfcip.PDUParam.tmpBuf->inf,
                *gNfcip.PDUParam.rxLen);
            gNfcip.PDURxPos += *gNfcip.PDUParam.rxLen;
        }

        /* Update output param rxLen */
        *gNfcip.PDUParam.rxLen = gNfcip.PDURxPos;

        /* Wait for following Block or PDU TxRx is done */
        return ((ret == ERR_AGAIN) ? ERR_BUSY : ERR_NONE);

    /*******************************************************************************/
    default:
        /* MISRA 16.4: no empty default statement (a comment being enough) */
        break;
    }

    return ret;
}

#endif /* RFAL_FEATURE_NFC_DEP */