Code:
;****************************************************************************************
PROCESSOR P16F877A
INCLUDE <P16F877A.inc>
__CONFIG _CP_OFF & _PWRTE_ON & _WDT_OFF & _HS_OSC & _LVP_OFF &_BODEN_OFF
;****************************************************************************************
ORG 0X20
COUNT1 EQU 0X20
COUNT2 EQU 0X21
COUNT3 EQU 0X22
;****************************************************************************************
ORG 0X0000
GOTO MAIN
; ORG 0X0004
; GOTO INTERRUPT
;*****************************************************************************************
ORG 0X0005
MAIN
BCF STATUS,RP1
BSF STATUS,RP0 ;BANK1
CLRF TRISC ;PORTC IS OUTPUT
BCF STATUS,RP0 ;BANK0
CLRF PORTC
GOTO C0
C0
BSF PORTC,0
CALL DELAY_LONG
BCF PORTC,0
CALL DELAY_LONG
C1
BSF PORTC,1
CALL DELAY_LONG
C2
BSF PORTC,2
CALL DELAY_LONG
BCF PORTC,2
CALL DELAY_LONG
GOTO C0
;*****************************************************************************************
DELAY_LONG
MOVLW D'5'
MOVWF COUNT3
DELAY_LONG_START
DECFSZ COUNT3,F
GOTO $+2
RETURN
CALL DELAY
GOTO DELAY_LONG_START
;******************************************************************************
DELAY
MOVLW D'255'
MOVWF COUNT1
LOOP1
MOVLW D'255'
MOVWF COUNT2
DECFSZ COUNT1,F
GOTO LOOP2
RETURN
LOOP2
DECFSZ COUNT2,F
GOTO LOOP2
GOTO LOOP1
END
ĐOẠN CODE TRÊN EM VIẾT THỬ CHO PORTC, EM THẮC MẮC LÀ TẠI SAO BIT1 NÓ SÁNG RỒI TẮT.NHỜ MỌI NGƯỜI CHỈ HỘ.CẢM ƠN NHIỀU.