Datasheet

SAM9261 [DATASHEET]
Atmel-6062O-ATARM-SAM9261-Datasheet_21-Jun-16
704
extern void soft_user_reset(void);
void sysc_handler(void){
//check if interrupt comes from RSTC
if( (*AT91C_RSTC_RSR & AT91C_RSTC_URSTS ) == AT91C_RSTC_URSTS){
soft_user_reset();
//never reached
while(1);
}
}
 Assembly code is mandatory for the following sequence as we need to pipeline ARM instructions. The
assembler routine:
AREA TEST, CODE
INCLUDE AT91SAM9xxx.inc
EXPORT soft_user_reset
soft_user_reset
;disable IRQs
MRS r0, CPSR
ORR r0, r0, #0x80
MSR CPSR_c, r0
;change refresh rate to block all data accesses
LDR r0, =AT91C_SDRAMC_TR
LDR r1, =1
STR r1, [r0]
;prepare power down command
LDR r0, =AT91C_SDRAMC_LPR
LDR r1, =2
;prepare proc_reset and periph_reset
LDR r2, =AT91C_RSTC_RCR
LDR r3, =0xA5000005
;perform power down command
STR r1, [r0]
;perform proc_reset and periph_reset (in the ARM pipeline)
STR r3, [r2]
END