Question

实施使电路板上的LED闪烁两次所需的汇编语言代码：250 mS 在/ 250 mS关闭。你选择哪个LED会闪烁

所以我们需要编写这段代码，但经过四个小时的工作，班上没有人可以到任何地方。因为我们实际上并没有学习集会而且教授是meh。这是我到目前为止的地方，真的需要帮助理解如何完成它或者我是否朝着正确的方向前进。

#include <PIC16f77a.inc>

TEMP_W      EQU 0X20        ;Temporary location for W during interrupt
TEMP_STATUS EQU 0X21        ;Temporary location for Status during interrupt
TIMERCOUNT  EQU 0X22

__CONFIG    0X0373A     ;This is the control bits for CONFIG register with the
                        ; watchdog timer enabled

ORG     0X0000          ;RESET or WDT reset vector
GOTO    START

ORG     0X0004          ;Regular INT vector`START
CLRF    PORTB           
CLRF    PORTC           
BSF     STATUS,RP0      
MOVLW   0X05            
MOVWF   PIE1                
MOVLW   0X05            
MOVWF   PIR1
MOVLW   0X02
MOVWF   TRISB   
MOVLW   0X04
MOVWF   TRISC
BCF     STATUS, PRO
MOVLW   0X80
MOVWF   INTCON
MOVLW   0X04
MOVWF   CCP1CON
MOVLW   0X0B
MOVWF   CCP1CON,0X04
MOVLW   0X33
MOVWF   T1CON`

Answer 1

使用定时器每250 ms产生一次中断，然后在某个端口异或一位。

Answer 2

#include <p16f877a.inc>

TEMP_W      EQU 0X20        ;Temporary location for W during interrupt
TEMP_STATUS EQU 0X21        ;Temporary location for Status during interrupt
TIMERCOUNT  EQU 0X22        

__CONFIG    0X373A      ;This is the control bits for CONFIG register with 
the
                        ; watchdog timer enabled

ORG     0X0000          ;RESET or WDT reset vector
GOTO    START

ORG     0X0004          ;Regular INT vector
PUSH
; This stores the current W and STATUS registers in temporary locations during ISRS
MOVWF   TEMP_W
SWAPF   STATUS,W
MOVWF   TEMP_STATUS
BTFSC   PIR1, CCP1IF
GOTO    TIMERINTR
POP
; This restores the original W and STATUS registers before returning to the 
main program
SWAPF   TEMP_STATUS,W
MOVWF   STATUS
SWAPF   TEMP_W,F
SWAPF   TEMP_W,W
RETFIE

TIMERINTR
INCF    TIMERCOUNT,F
BCF     PIR1, CCP1IF
GOTO    POP

START
CLRF    TIMERCOUNT
BCF     INTCON, GIE
CLRF    PORTC
BSF     STATUS,RP0  
MOVLW   0X00
MOVWF   TRISC
BSF     PIE1, CCP1IE
BCF     STATUS, RP0 
BSF     INTCON, PEIE
CLRF    TMR1H
CLRF    TMR1L
MOVLW   0X01
MOVWF   T1CON
MOVLW   0X0B
MOVWF   CCP1CON
MOVLW   0X13
MOVWF   CCPR1H
MOVLW   0X88
MOVWF   CCPR1L
BSF     INTCON, GIE


LOOPTIME
MOVLW   0XFA
XORWF   TIMERCOUNT, W
BTFSC   STATUS, Z
GOTO    OUTPUT

GOTO    LOOPTIME

OUTPUT
MOVLW   0X80
XORWF   PORTC, RC7
CLRF    TIMERCOUNT
GOTO    LOOPTIME

RETURN

END

我需要使用组件使用中断来使LED每秒亮两次

2 个答案: