NUC972 >> Assembly

Button

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參考資訊：
1. pdf
2. NUC970_NonOS_BSP

Pull-Up Enable


main.s

  .equ GPIOB_DIR,     (0xb8003000 + 0x40)
  .equ GPIOB_DATAOUT, (0xb8003000 + 0x44)
  .equ GPIOB_DATAIN,  (0xb8003000 + 0x48)
  .equ GPIOB_PUEN,    (0xb8003000 + 0x60)
  .equ CLK_PCLKEN0,   (0xb0000200 + 0x18)
 
  .text
  .align 2
  .global _start
_start:    b reset
_undef:    b .
_swi:      b .
_pabort:   b .
_dabort:   b .
_reserved: b .
_irq:      b .
_fiq:      b .
 
reset:
  ldr r0, =CLK_PCLKEN0
  ldr r1, [r0]
  orr r1, #(1 << 3)
  str r1, [r0]
 
  ldr r0, =GPIOB_DIR
  ldr r1, =(1 << 0)
  str r1, [r0]
   
  ldr r0, =GPIOB_PUEN
  ldr r1, =(1 << 1)
  str r1, [r0]   
loop:
  ldr r0, =GPIOB_DATAIN
  ldr r0, [r0]
  and r0, #(1 << 1)
  cmp r0, #(1 << 1)
  bne 1f
0:
  ldr r0, =GPIOB_DATAOUT
  ldr r1, =(1 << 0)
  str r1, [r0]
  b loop
1:
  ldr r0, =GPIOB_DATAOUT
  ldr r1, =~(1 << 0)
  str r1, [r0]
  b loop
  .end

完成

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