微處理器 - NXP LPC2103 - Assembly - Timer0

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

暫存器





main.s

    .equ IODIR,        0xe0028008
    .equ IOCLR,        0xe002800c
    .equ IOSET,        0xe0028004
    .equ PINSEL0,      0xe002c000
    .equ EXTINT,       0xe01fc140
    .equ VICIntEnable, 0xfffff010
    .equ T0PR,         0xe000400c
    .equ T0MR0,        0xe0004018
    .equ T0MCR,        0xe0004014
    .equ T0TCR,        0xe0004004
    .equ T0CTCR,       0xe0004070
    .equ T0IR,         0xe0004000

    .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, =T0PR
    ldr r1, =0x63
    str r1, [r0]
 
    ldr r0, =T0MR0
    ldr r1, =5000
    str r1, [r0]
 
    ldr r0, =T0MCR
    ldr r1, [r0]
    orr r1, #0x03
    str r1, [r0]
 
    ldr r0, =T0TCR
    ldr r1, =0x02
    str r1, [r0]
 
    ldr r0, =T0TCR
    ldr r1, =0x01
    str r1, [r0]
 
    ldr r0, =VICIntEnable
    ldr r1, =(1 << 4)
    str r1, [r0]
 
    ldr r0, =IODIR
    ldr r1, =(1 << 22)
    str r1, [r0]
   
    ldr r0, =IOCLR
    ldr r1, =(1 << 22)
    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, =IOSET
    ldr r1, =(1 << 22)
    str r1, [r0]
    b 2f
1:
    ldr r0, =IOCLR
    ldr r1, =(1 << 22)
    str r1, [r0]
2:
    ldr r0, =blink
    ldr r1, [r0]
    eor r1, #0xff
    str r1, [r0]

    ldr r0, =T0IR
    ldr r1, =0x01
    str r1, [r0]
    subs pc, lr, #4
    .end

完成