微處理器 - NXP LPC812 - Assembly - Button

參考資訊：
https://github.com/BakaOsaka/LPC810-ASM
https://studio.segger.com/packages/LPC800/CMSIS/Documents/UM10601.pdf

Register


main.S

    .cpu cortex-m0
    .thumb

    .equ GPIO_DIR0, 0xa0002000
    .equ GPIO_PIN0, 0xa0002100
    .equ GPIO_SET0, 0xa0002200
    .equ GPIO_CLR0, 0xa0002280

    .equ BIT1,  1
    .equ BIT7,  7
    .equ BIT16, 16
    .equ BIT17, 17

    .thumb_func
    .global _start
_start:
    .word 0x10000400 @ stacktop
    .word reset @ reset
    .word hang @ nmi
    .word hang @ hardfault
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ svcall
    .word hang @ reserved
    .word hang @ reserved
    .word hang @ pendsv
    .word hang @ systick

    .thumb_func
reset:
    ldr r1, =((1 << BIT7) | (1 << BIT16) | (1 << BIT17))
    ldr r0, =GPIO_DIR0
    str r1, [r0]
    ldr r0, =GPIO_SET0
    str r1, [r0]

loop:
    ldr r0, =GPIO_PIN0
    ldr r0, [r0]
    ldr r1, =(1 << BIT1)
    and r0, r1
    cmp r0, #0
    beq 1f

    ldr r0, =GPIO_SET0
    ldr r1, =(1 << BIT7)
    str r1, [r0]
    b loop

1:
    ldr r0, =GPIO_CLR0
    ldr r1, =(1 << BIT7)
    str r1, [r0]
    b loop

hang:
    b .
    .end

完成