LPC2103 >> Assembly
EINT1(Non-vectored IRQ)
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 VICDefVectAddr, 0xfffff034 .equ VICVectAddr0, 0xfffff100 .equ VICVectCntl0, 0xfffff200 .text .align 2 .global _start _start: b reset _undef: b . _swi: b . _pabort: b . _dabort: b . _reserved: b . _irq: ldr pc, [pc, #-0xff0] _fiq: b . reset: mrs r0, cpsr bic r0, #0x80 msr cpsr_c, r0 ldr r0, =PINSEL0 ldr r1, =(1 << 28) str r1, [r0] ldr r0, =VICIntEnable ldr r1, =(1 << 15) str r1, [r0] ldr r0, =VICDefVectAddr ldr r1, =irq_handler str r1, [r0] ldr r0, =VICVectCntl0 ldr r1, =0x0f str r1, [r0] ldr r0, =IODIR ldr r1, =(1 << 22) str r1, [r0] ldr r0, =IOCLR ldr r1, =(1 << 22) str r1, [r0] b . irq_handler: ldr r0, =IOSET ldr r1, =(1 << 22) str r1, [r0] ldr r0, =EXTINT ldr r1, =0x02 str r1, [r0] subs pc, lr, #4 .end
P.S. ldr pc, [pc, #-0xff0] = 0x18(irq address) + 8(fetch、decode) - 0xff0 = VICVectAddr(0xfffff030)
完成
