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On LWMON we must use the watchdog to reset the board as the CPU

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genereated HRESET pulse is too short to reset the external circuitry.
This commit is contained in:
wdenk 2005-05-09 10:17:32 +00:00
parent 931da93e0f
commit ed16fefcba
3 changed files with 37 additions and 1 deletions
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4
CHANGELOG
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@ -2,6 +2,10 @@
Changes for U-Boot 1.1.3:
======================================================================
* On LWMON we must use the watchdog to reset the board as the CPU
genereated HRESET pulse is too short to reset the external
circuitry.
* Add test tool to exercise SDRAM accesses in burst mode
(as standalone program, MPC8xx/PowerPC only)

3
Makefile
View file

@ -1651,7 +1651,8 @@ clean:
| xargs rm -f
rm -f examples/hello_world examples/timer \
examples/eepro100_eeprom examples/sched \
examples/mem_to_mem_idma2intr examples/82559_eeprom
examples/mem_to_mem_idma2intr examples/82559_eeprom \
examples/test_burst
rm -f tools/img2srec tools/mkimage tools/envcrc tools/gen_eth_addr
rm -f tools/mpc86x_clk tools/ncb
rm -f tools/easylogo/easylogo tools/bmp_logo

31
cpu/mpc8xx/cpu.c
View file

@ -463,6 +463,8 @@ void upmconfig (uint upm, uint * table, uint size)
/* ------------------------------------------------------------------------- */
#ifndef CONFIG_LWMON
int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
ulong msr, addr;
@ -497,6 +499,32 @@ int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return 1;
}
#else /* CONFIG_LWMON */
/*
* On the LWMON board, the MCLR reset input of the PIC's on the board
* uses a 47K/1n RC combination which has a 47us time constant. The
* low signal on the HRESET pin of the CPU is only 512 clocks = 8 us
* and thus too short to reset the external hardware. So we use the
* watchdog to reset the board.
*/
int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
/* prevent triggering the watchdog */
disable_interrupts ();
/* make sure the watchdog is running */
reset_8xx_watchdog ((immap_t *) CFG_IMMR);
/* wait for watchdog reset */
while (1) {};
/* NOTREACHED */
return 1;
}
#endif /* CONFIG_LWMON */
/* ------------------------------------------------------------------------- */
/*
@ -558,6 +586,9 @@ void watchdog_reset (void)
if (re_enable)
enable_interrupts ();
}
#endif /* CONFIG_WATCHDOG */
#if defined(CONFIG_WATCHDOG) || defined(CONFIG_LWMON)
void reset_8xx_watchdog (volatile immap_t * immr)
{