最近遇到的问题，液晶说什么也不显示，期望高手指点。程序如下：
list p=16f873a ; list directive to define processor
#include <p16f873a.inc> ; processor specific variable definitions
; __CONFIG _CP_OFF & _WDT_ON & _BODEN_ON & _PWRTE_ON & _XT_OSC
;-------------------------------
;RB1 --> SID
;RB0 --> SCL
;RC0 --> RS
;RC1 --> CS1
;RA3 --> RESET
;-------------------------------
;***** VARIABLE DEFINITIONS
CBLOCK 0X20
PR_COUNT
PR_OUT
PR_DATA
LCD_D_CON1
LCD_D_CON2
DAT1
DAT2
D5_COUNT1
D5_COUNT2
ENDC
;**********************************************************************
ORG 0X000 ; PROCESSOR RESET VECTOR
NOP
GOTO INITIAL ; GO TO BEGINNING OF PROGRAM
ORG 0X004 ; INTERRUPT VECTOR LOCATION
RETFIE ; RETURN FROM INTERRUPT
INITIAL ;初始化程序
;--------------------------------
;SPECIAL REG
;--------------------------------
CLRWDT
BCF STATUS,RP0
CLRF PORTA
CLRF PORTB
CLRF PORTC
MOVLW 0X80 ;10000000
MOVWF ADCON0
CLRF ADRESH ;873
MOVLW 0C0H ;11000000
MOVWF RCSTA
BSF STATUS,RP0
CLRF TRISA
CLRF TRISB ;RB0-RB7,总线
MOVLW 0X80 ;1000,0000
MOVWF TRISC
MOVLW 0X02 ;
MOVWF ADCON1
CLRF ADRESL ;873
MOVLW 0X0D ;0000 1110
MOVWF OPTION_REG
;-------------------------------
BCF STATUS,RP0
CALL LCD_INITIAL
;-------------------------------
;上电
;-------------------------------
BSF STATUS,RP0
BSF PCON,1 ;POWER-ON
BSF PCON,0 ;BOD
;---------------------------------
; MAIN PROGRAM
;---------------------------------
MAIN
CLRWDT
BCF STATUS,RP0
MOVLW 0B0H ;初始页地址
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 10H ;初始列地址高8位
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0H ;初始列地址低8位
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0A5H ;全显
MOVWF PR_DATA
CALL LCD_PR1
CALL LCD_DELAY1
CALL LCD_DELAY1
CALL LCD_DELAY1
GOTO $
GOTO MAIN
;---------------------------------
; -SUBPROGRAM- 液晶初始化
LCD_INITIAL
;---------------------------------
BCF STATUS,RP0
BCF PORTA,3 ;硬件复位
CALL LCD_DELAY1
BSF PORTA,3
MOVLW 0E2H ;软件复位
MOVWF PR_DATA
CALL LCD_PR1
CALL LCD_DELAY1
MOVLW 0A2H ;LCD BIAS=1/9
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0A0H ;列地址移动方向:ADC=0
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0C8H ;行扫描方向:SHL=1
MOVWF PR_DATA
CALL LCD_PR1
CALL LCD_DELAY1
MOVLW 02FH ;电源控制模式:vc,vr,vf=111
MOVWF PR_DATA
CALL LCD_PR1
CALL LCD_DELAY1
MOVLW 26H ;内部调整电阻比:R2,R1,R0=111
MOVWF PR_DATA
CALL LCD_PR1
CALL LCD_DELAY1
MOVLW 81H ;对比度寄存器模式
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 20H ;对比度寄存器值
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 40H ;起始行
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0E0H ;写入数据时列地址自动加1，读不变
MOVWF PR_DATA
CALL LCD_PR1
MOVLW 0AFH ;开显示
MOVWF PR_DATA
CALL LCD_PR1
RETURN
;---------------------------------
; -SUBPROGRAM- 写入控制命令
LCD_PR1
;---------------------------------
BCF STATUS,RP0
MOVLW 8H
MOVWF PR_COUNT
BCF PORTC,1 ;选芯片
BCF PORTC,0 ;选命令寄存器
MOVF PR_DATA,W ;将要发送的数据送入发送寄存器PR_OUT
MOVWF PR_OUT
LCD_I_WRITE1
BCF PORTB,0 ;SCL=0
BTFSS PR_OUT,7 ;判断发送寄存器最高位值，输出到SID
BCF PORTB,1
BTFSC PR_OUT,7
BSF PORTB,1
NOP
NOP
BSF PORTB,0 ;SCL=1
NOP
NOP
DECFSZ PR_COUNT,F ;判断循环次数
GOTO LCD_I_WRITE2 ;不为0跳转至LCD_I_WRITE2
BSF PORTC,1 ;为0，恢复芯片并返回
RETURN
LCD_I_WRITE2
RLF PR_OUT,F ;左移一位
GOTO LCD_I_WRITE1
RETURN
;---------------------------------
; -SUBPROGRAM- 写入显示数据
LCD_PR2
;---------------------------------
MOVLW 8H
MOVWF PR_COUNT
BSF PORTC,0 ;选数据寄存器
BCF PORTC,1
MOVF PR_DATA,W
MOVWF PR_OUT
LCD_D_WRITE1
BCF PORTB,0
BTFSS PR_OUT,7
BCF PORTB,1
BTFSC PR_OUT,7
BSF PORTB,1
NOP
NOP
BSF PORTB,0
NOP
NOP
DECFSZ PR_COUNT,F
GOTO LCD_D_WRITE2
BSF PORTC,1
RETURN
LCD_D_WRITE2
RLF PR_OUT,F
GOTO LCD_D_WRITE1
RETURN
;---------------------------------
; -SUBPROGRAM- 400us 4M晶振，延时400us
LCD_DELAY1
;---------------------------------
BCF STATUS,RP0
MOVLW 17H
MOVWF LCD_D_CON1
LCD_DLOOP1
CLRWDT
DECFSZ LCD_D_CON1,1
GOTO LCD_DLOOP1
NOP
NOP
RETURN
;---------------------------------
; -SUBPROGRAM- 0.64S 4M晶振，延时约0.64s
LCD_DELAY2
;---------------------------------
BCF STATUS,RP0
MOVLW 80H
MOVWF LCD_D_CON2
LDLOOP
DECFSZ LCD_D_CON2
GOTO $+2
RETURN
CALL DELAY_5MS
GOTO LDLOOP
RETURN
;---------------------------------
; -SUBPROGRAM- 5MS 4M晶振，延时5ms
DELAY_5MS
;---------------------------------
BCF STATUS,RP0
MOVLW 0FH
MOVWF D5_COUNT1
D5_LOOP2
MOVLW 6DH
MOVWF D5_COUNT2
D5_LOOP1
DECFSZ D_COUNT1,1
GOTO D5_LOOP1
DECFSZ D_COUNT2,1
GOTO D5_LOOP2
RETURN
;---------------------------------
END
小弟先谢过了。 |
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