;;;;;;;;;;Проба работы в 4 битном режиме;;;;;;;;;;;;; ; LCD: D0-D7 подключены к RB0-RB7 ; E - RA3, RS - RA2, R/W - GND ;================================================================ LIST P=16F84A __CONFIG _XT_OSC & _CP_OFF & _PWRTE_OFF & _WDT_OFF include P16F84A.inc ;================================================================ Var_1 equ 20h ; Var_2 equ 21h ; ;================================================================ #define RS PORTA,2 ; вывод RS #define E PORTA,3 ; вывод E #define LCD_PORT PORTB org 0 ; ;================================================================ clrf STATUS ; Настройка выводов МК clrf PORTA ; clrf PORTB ; bsf STATUS,RP0 ; clrf TRISA ; clrf TRISB ; bcf STATUS,RP0 ; ;===================== ; Variable Definitions cblock H'20' delay_1 delay_2 delay_3 tempLCD endc ;============== ; Reset Vector ;org 0x0000 goto Start Init ;===================== ; Set up port and pins banksel TRISB ; select TRISC bus movlw B'00000000' ; all pins output movwf TRISB banksel PORTB ; select LATC and clear clrf PORTB return ;============================================ ; Delay subroutine which lasts for 100 * cty delay_long movwf delay_3 delay_long_loop2 movlw D'13' movwf delay_2 clrf delay_1 delay_long_loop1 decfsz delay_1,f goto delay_long_loop1 decfsz delay_2,f goto delay_long_loop1 decfsz delay_3,f goto delay_long_loop2 return ;============================ ; Delay subroutine 1000 * cty delay_short movwf delay_2 delay_short_loop2 movlw D'249' movwf delay_1 delay_short_loop1 nop decfsz delay_1,f goto delay_short_loop1 decfsz delay_2,f goto delay_short_loop2 return ;================== ;LCD Initialisation LCD_Init movlw D'5' call delay_long ;banksel PORTB bcf RS ; commands so RS bit set low movlw b'00010000' ; must be more than 15ms call delay_short ;banksel PORTB movlw 0x03 ; send first high nibble movwf LCD_PORT call Nibble movlw D'6' ; must be more than 4.1ms call delay_short ;banksel PORTB movlw 0x03 ; send second high nibble movwf LCD_PORT call Nibble movlw D'1' ; must be more than 100us call delay_short ;banksel PORTB movlw 0x03 ; send third high nibble movwf LCD_PORT call Nibble movlw D'5' ; must be more than 5ms call delay_short ;banksel PORTB movlw 0x02 ; set 4 bit mode movwf LCD_PORT call Nibble movlw 0x28 ; function set: 4 bit, 2 lines, 5 x 7 font call LCD_Cmd movlw 0x08 ; display switch: D = 0, C = 0, B = 0 call LCD_Cmd call LCD_Clear movlw 0x0C ; display switch: D = 1, C = 0, B = 0 call LCD_Cmd movlw 0x06 ; input set: I/D = 1, S = 0 call LCD_Cmd ;banksel PORTB ; make sure LATC port is clear clrf PORTB movlw D'50' ; initialisation delay call delay_long return ;============ ; LCD Command LCD_Cmd movwf tempLCD ; move contents of w into tempLCD swapf tempLCD,w ; swap contents of tempLCD put result in w andlw 0x0f ; select high nibble movwf LCD_PORT bcf RS ; RS set low due to instruction write call Nibble movlw D'1' call delay_short movfw tempLCD ; move contents of tempLCD into w andlw 0x0f ; select low nibble movwf LCD_PORT bcf RS ; RS set low due to instruction write call Nibble movlw D'1' call delay_short return ;========== ; LCD Write LCD_Write movwf tempLCD ; move contents of w into tempLCD swapf tempLCD,w ; поменять местами содержимое tempLCD положить результат в w andlw 0xf ; Выбрать старший полубайт movwf LCD_PORT ; Записать в порт bsf RS ; RS set high due to instruction write call Nibble movlw D'1' call delay_short movfw tempLCD ; move contents of tempLCD into w andlw 0xf ; select low nibble movwf LCD_PORT bsf RS ; RS set high due to instruction write call Nibble movlw D'5' ; vary this delay to control writing speed call delay_long return ;=========================== ; Send nibble - toggle E pin Nibble bsf E ; E set high movlw D'1' call delay_short bcf E ; E set low movlw D'2' call delay_short return ;=========== ; LCD line 1 LCD_Line1 movlw 0x80 call LCD_Cmd return ;=========== ; LCD line 2 LCD_Line2 movlw 0xC0 call LCD_Cmd return ;============== ; Clear Command LCD_Clear movlw 0x01 call LCD_Cmd return ;============ ; Write Space LCD_Space movlw 0x20 call LCD_Write return ;============= ; Program main Start call Init call LCD_Init Main call LCD_Clear call LCD_Line1 Top_Line movlw b'01001000' ; H call LCD_Write movlw 'e' call LCD_Write movlw 'l' call LCD_Write movlw 'l' call LCD_Write movlw 'o' call LCD_Write call LCD_Space movlw 'W' call LCD_Write movlw 'o' call LCD_Write movlw 'r' call LCD_Write movlw 'l' call LCD_Write movlw 'd' call LCD_Write movlw D'255' call delay_long Bottom_Line call LCD_Line2 movlw 'L' call LCD_Write movlw 'C' call LCD_Write movlw 'D' call LCD_Write movlw ' ' call LCD_Write call LCD_Space movlw 'p' call LCD_Write movlw 'i' call LCD_Write movlw 'c' call LCD_Write movlw '1' call LCD_Write movlw '6' call LCD_Write movlw 'f' call LCD_Write movlw D'255' call delay_long goto $ ; loop forever end