暫存器
Prescaler
步驟:
1. IWDG_KR(0xcc) > Enable
2. IWDG_KR(0x55) > Unlock IWDG_PR and IWDG_RLR
3. IWDG_KR(0xaa) > Reload IWDG_PR and IWDG_RLR
main.s
.equ PB_ODR, 0x5005 .equ PB_IDR, 0x5006 .equ PB_DDR, 0x5007 .equ PB_CR1, 0x5008 .equ PB_CR2, 0x5009 .equ IWDG_KR, 0x50e0 .equ IWDG_PR, 0x50e1 .equ IWDG_RLR, 0x50e2 .area data .area sseg .area home int main .area cseg main: mov PB_DDR, #0x20 mov PB_CR1, #0x20 mov IWDG_KR, #0xcc mov IWDG_KR, #0x55 mov IWDG_RLR, #0xff mov IWDG_PR, #0x06 mov IWDG_KR, #0xaa loop: ld a, PB_ODR xor a, #0x20 ld PB_ODR, a ldw x, #5000 d0: decw x tnzw x jrne d0 jp loop
觀察LED的變化,即可發現每秒會有一次閃動變化