at91_blinky.s

#include <targets/AT91SAM7.h>
.global main
main:
  
# Output enable
  ldr r0, =(PIOA_BASE + PIOA_OER_OFFSET) 
  ldr r1, =PIOA_OER_P18_MASK 
  str r1, [r0]

loopreset:

# Output set to 1
  ldr r0, =(PIOA_BASE + PIOA_SODR_OFFSET)
  ldr r1, =PIOA_SODR_P18_MASK
  str r1, [r0]

# Counter reset
  mov r2, #0x0

loopone:
  add r2,r2,#0x1
  cmp r2,#0x00100000
  bne loopone

# Output set to 0
  ldr r0, =(PIOA_BASE + PIOA_CODR_OFFSET)
  ldr r1, =PIOA_CODR_P18_MASK
  str r1, [r0]

# Counter reset
  mov r2, #0x0

looptwo:
  add r2,r2,#0x1
  cmp r2,#0x00100000
  bne looptwo

  b loopreset