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Update the README for DDR ECC, change the name to README.mpc83xx.ddrecc. Signed-off-by: Dave Liu <daveliu@freescale.com> Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
154 lines
4.5 KiB
Text
154 lines
4.5 KiB
Text
Overview
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========
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The overall usage pattern for ECC diagnostic commands is the following:
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* (injecting errors is initially disabled)
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* define inject mask (which tells the DDR controller what type of errors
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we'll be injecting: single/multiple bit etc.)
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* enable injecting errors - from now on the controller injects errors as
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indicated in the inject mask
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IMPORTANT NOTICE: enabling injecting multiple-bit errors is potentially
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dangerous as such errors are NOT corrected by the controller. Therefore caution
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should be taken when enabling the injection of multiple-bit errors: it is only
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safe when used on a carefully selected memory area and used under control of
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the 'ecc testdw' 'ecc testword' command (see example 'Injecting Multiple-Bit
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Errors' below). In particular, when you simply set the multiple-bit errors in
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inject mask and enable injection, U-Boot is very likely to hang quickly as the
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errors will be injected when it accesses its code, data etc.
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Use cases for DDR 'ecc' command:
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================================
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Before executing particular tests reset target board or clear status registers:
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=> ecc captureclear
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=> ecc errdetectclr all
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=> ecc sbecnt 0
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Injecting Single-Bit Errors
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---------------------------
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1. Set 1 bit in Data Path Error Inject Mask
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=> ecc injectdatahi 1
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2. Run test over some memory region
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=> ecc testdw 200000 10
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3. Check ECC status
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=> ecc status
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...
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Memory Data Path Error Injection Mask High/Low: 00000001 00000000
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...
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Memory Single-Bit Error Management (0..255):
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Single-Bit Error Threshold: 255
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Single Bit Error Counter: 16
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...
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Memory Error Detect:
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Multiple Memory Errors: 0
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Multiple-Bit Error: 0
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Single-Bit Error: 0
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...
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16 errors were generated, Single-Bit Error flag was not set as Single Bit Error
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Counter did not reach Single-Bit Error Threshold.
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4. Make sure used memory region got re-initialized with 0x0123456789abcdef
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=> md 200000
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00200000: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200010: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200020: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200030: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200040: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200050: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200060: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200070: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200080: deadbeef deadbeef deadbeef deadbeef ................
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00200090: deadbeef deadbeef deadbeef deadbeef ................
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Injecting Multiple-Bit Errors
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-----------------------------
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1. Set more than 1 bit in Data Path Error Inject Mask
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=> ecc injectdatahi 1
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=> ecc injectdatalo 1
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2. Run test over some memory region
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=> ecc testword 200000 1
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3. Check ECC status
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=> ecc status
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...
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Memory Data Path Error Injection Mask High/Low: 00000001 00000001
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...
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Memory Error Detect:
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Multiple Memory Errors: 0
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Multiple-Bit Error: 1
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Single-Bit Error: 0
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...
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The Multiple Memory Errors flags not set and Multiple-Bit Error flags are set.
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4. Make sure used memory region got re-initialized with 0x0123456789abcdef
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=> md 200000
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00200000: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200010: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200020: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200030: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200040: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200050: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200060: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200070: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
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00200080: deadbeef deadbeef deadbeef deadbeef ................
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00200090: deadbeef deadbeef deadbeef deadbeef ................
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Test Single-Bit Error Counter and Threshold
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-------------------------------------------
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1. Set 1 bit in Data Path Error Inject Mask
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=> ecc injectdatahi 1
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2. Enable error injection
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=> ecc inject en
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3. Let u-boot run for a with Single-Bit error injection enabled
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4. Disable error injection
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=> ecc inject dis
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4. Check status
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=> ecc status
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...
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Memory Single-Bit Error Management (0..255):
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Single-Bit Error Threshold: 255
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Single Bit Error Counter: 199
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Memory Error Detect:
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Multiple Memory Errors: 1
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Multiple-Bit Error: 0
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Single-Bit Error: 1
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...
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Observe that Single-Bit Error is 'on' which means that Single-Bit Error Counter
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reached Single-Bit Error Threshold. Multiple Memory Errors bit is also 'on', that
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is Counter reached Threshold more than one time (it wraps back after reaching
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Threshold).
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