我正在爲ATmega16編寫這個程序集,我只是想讓按鈕按下時閃爍10次LED。不幸的是,當達到RET指令時,它將我帶到第一個代碼(start),而不是在調用LONG_DELAY時返回它的左邊。RET指令沒有返回到它所謂的子程序 - AVR程序集
有人可以幫我嗎?謝謝。
start:
/* set the PINB0 data direction to 0 for input */
/* This one simulates the key */
ldi R16, (0 << PB0) ; Load 0b00000001 in R16
out DDRB,R16 ; Configure the PINB0 as input
/* set the PORTB7 data direction to 1 for output */
/* this one causes the LED to be ON/OFF */
ldi R17, (1 << PB7) ; Load 0b10000000 in R17
out DDRB,R17 ; Configure the PORTB7 as output
OFF_MODE:
/* Put the PORTB7 to 0 */
ldi R18,(0 << PB7)
out PORTB,R18
/* Check the content of PINB0 */
/* Wait for the PINB to get pressed by the user */
sbis PINB,0
brne OFF_MODE ; Branch to the OFF_MODE if the key isn't pressed yet
BLINK_MODE:
/* Define a counter */
ldi R20,0
/* Turn on the LED */
/* Put the PORTB7 to 1 */
ldi R18,(1 << PB7)
out PORTB,R18
/* Create a delay */
call LONG_DELAY
/* Turn off the LED */
ldi R18,(0 << PB7)
out PORTB,R18
/* Increment the counter */
inc R20
/* Check the content of the counter */
cpi R20,0x0A
brne BLINK_MODE
/* Clear the input to avoid duplicate press virtualization */
cbi PINB,0
jmp OFF_MODE
rjmp start
/* Delay function */
LONG_DELAY:
ldi r25,10
LOOP:
nop
dec R25
cpi R25,0
brne LOOP
ret
不能當場什麼錯乍一看,你怎麼知道它可以追溯到'start'? – Jester
@Jester我正在用AtmelStudio 7調試它。 – aligholamee
你應該初始化堆棧指針。 – Jester