微處理器 - Nuvoton NUC972 - Assembly - Button

參考資訊：
https://github.com/OpenNuvoton/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