The 8051 Microcontroller and Embedded

Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

8255 HANEL

INTERFACING

LCD

Connection To The 8255

(cont

;Writing commands to the LC’)

D without checking busy flag

;PA of 8255 connected

to D0-D7 of LCD and

;PB0=RS, PB1=R/W, PB2=E for 8255 to LCD

’s control pins connection

MOV A,#80H ;all 8

255 ports as output

MOV R0,#CNTPORT ;load

control reg address

MOVX @R0,A ;issue control wordMOV A,#38H ;LCD:2 LINES, 5X7 matrixACALL NCMDWRT ;write command to LCDMOV A,#0EH ;LCD c

ommand for cursor on

ACALL NCMDWRT ;write command to LCDMOV A,#01H ;clear LCDACALL NCMDWRT ;write command to LCDMOV A,#06H ;shift cursor right commandACALL NCMDWRT ;write command to LCD.... ;etc. for all LCD commandsMOV A,#’N’ ;display data (letter N)ACALL NDATAWRT ;send data to LCD displayMOV A,#’O’ ;display data (letter O)CALL NDATAWRT ;send data to LCD display.... ;etc. for other dataProgram 15-2.