微處理器 - NXP LPC2103 - Assembly - Button

參考資料：
https://www.keil.com/dd/docs/datashts/philips/user_manual_lpc2101_2102_2103.pdf

暫存器


main.s

    .equ IOPIN, 0xe0028000
    .equ IOSET, 0xe0028004
    .equ IODIR, 0xe0028008
    .equ IOCLR, 0xe002800c

    .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, =IODIR
    ldr r1, =(1 << 22)
    str r1, [r0]
loop:
    ldr r0, =IOPIN
    ldr r0, [r0]
    and r0, #(1 << 14)
    cmp r0, #(1 << 14)
    bne 1f
0:
    ldr r0, =IOCLR
    ldr r1, =(1 << 22)
    str r1, [r0]
    b loop
1:
    ldr r0, =IOSET
    ldr r1, =(1 << 22)
    str r1, [r0]
    b loop
    .end 

完成