微處理器 - TI DM3730 (BeagleBoard-XM) - Assembly - Button



USR按鍵是連接到GPIO-4


GPIO-4是屬於GPIO1


GPIO1 Clock


Input


Data


main.s

    .global _start

    .equ CM_ICLKEN_WKUP, 0x48004c10
    .equ CM_ICLKEN_PER,  0x48005010
    .equ GPIO5_OE,       0x49056034
    .equ GPIO5_DATAOUT,  0x4905603c
    .equ GPIO1_OE,       0x48310034
    .equ GPIO1_DATAIN,   0x48310038
    .equ GPIO1_DATAOUT,  0x4831003c
   
    .arm
    .text
_start:
    b reset
    b .
    b .
    b .
    b .
    b .
    b .
    b .
       
reset:
    ldr r0, =CM_ICLKEN_WKUP
    ldr r1, =(1 << 3)
    str r1, [r0]
  
    ldr r0, =CM_ICLKEN_PER
    ldr r1, =(1 << 16)
    str r1, [r0]
  
    ldr r0, =GPIO1_OE
    ldr r1, =(1 << 4)
    str r1, [r0]
  
    ldr r0, =GPIO5_OE
    ldr r1, =0
    str r1, [r0]
  
    ldr r0, =GPIO5_DATAOUT
    ldr r1, =(1 << 21)
    str r1, [r0]

    ldr r4, =GPIO1_DATAIN
0:
    ldr r2, [r4]
    lsl r2, #17
    str r2, [r0]
    b 0b
    .end

完成