微處理器 - Nuvoton NUC977 - Assembly - Timer4

參考資訊：
https://github.com/OpenNuvoton/NUC970_NonOS_BSP

Timer Interrupt


CE、IE、Mode


Compare


Flag


main.s

    .equ GPIOD_DIR,     (0xb8003000 + 0xc0)
    .equ GPIOD_DATAOUT, (0xb8003000 + 0xc4)
    .equ CLK_PCLKEN0,   (0xb0000200 + 0x18)
    .equ AIC_MECRH,     (0xb8002000 + 0x134)
    .equ AIC_EOSCR,     (0xb8002000 + 0x150)
    .equ TMR4_CSR,      (0xb8001000 + 0x40)
    .equ TMR4_CMPR,     (0xb8001000 + 0x44)
    .equ TMR4_DR,       (0xb8001000 + 0x48)
    .equ TMR_ISR,       (0xb8001000 + 0x60)

    .data
blink: .dcb 1

    .text
    .align 2
    .global _start
_start:    b reset
_undef:    b .
_swi:      b .
_pabort:   b .
_dabort:   b .
_reserved: b .
_irq:      b irq_handler
_fiq:      b .
 
reset:
    mrs r0, cpsr
    bic r0, #0x80
    msr cpsr_c, r0

    ldr r0, =AIC_MECRH
    ldr r1, =(1 << 0)
    str r1, [r0]

    ldr r0, =CLK_PCLKEN0
    ldr r1, [r0]
    ldr r2, =((1 << 3) | (1 << 12))
    orr r1, r2
    str r1, [r0]

    ldr r0, =TMR4_CMPR
    ldr r1, =(12000000 >> 1)
    str r1, [r0]

    ldr r0, =TMR4_CSR
    ldr r1, =0x60000000
    str r1, [r0]

    ldr r0, =GPIOD_DIR
    ldr r1, =(1 << 6)
    str r1, [r0]

    ldr r0, =GPIOD_DATAOUT
    ldr r1, =(1 << 6)
    str r1, [r0]

    ldr r0, =blink
    ldr r1, =0x00
    str r1, [r0]
    b .
 
irq_handler:
    ldr r0, =blink
    ldr r1, [r0]
    cmp r1, #0x00
    beq 1f
    ldr r0, =GPIOD_DATAOUT
    ldr r1, =(1 << 6)
    str r1, [r0]
    b 2f
1:
    ldr r0, =GPIOD_DATAOUT
    ldr r1, =~(1 << 6)
    str r1, [r0]
2:
    ldr r0, =blink
    ldr r1, [r0]
    eor r1, #0xff
    str r1, [r0]

    ldr r0, =AIC_EOSCR
    ldr r1, =1
    str r1, [r0]

    ldr r0, =TMR_ISR
    ldr r1, [r0]
    orr r1, #0x10
    str r1, [r0]

    ldr r0, =TMR4_CSR
    ldr r1, [r0]
    orr r1, #(1 << 30)
    str r1, [r0]

    subs pc, lr, #4
    .end

完成