LPC2103 >> Assembly

Timer1


參考資料:
1. 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 T1PR,         0xe000800c
  .equ T1MR0,        0xe0008018
  .equ T1MCR,        0xe0008014
  .equ T1TCR,        0xe0008004
  .equ T1CTCR,       0xe0008070
  .equ T1IR,         0xe0008000

  .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, =T1PR
  ldr r1, =0x63
  str r1, [r0]
 
  ldr r0, =T1MR0
  ldr r1, =5000
  str r1, [r0]
 
  ldr r0, =T1MCR
  ldr r1, [r0]
  orr r1, #0x03
  str r1, [r0]
 
  ldr r0, =T1TCR
  ldr r1, =0x02
  str r1, [r0]
 
  ldr r0, =T1TCR
  ldr r1, =0x01
  str r1, [r0]
 
  ldr r0, =VICIntEnable
  ldr r1, =(1 << 5)
  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, =T1IR
  ldr r1, =0x01
  str r1, [r0]
  subs pc, lr, #4
  .end

完成


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