Can help me check this source code. It is about optical encoder interfacing wiht 8051 and display result on a LED.






.ORG 0H
JMP MAIN
.ORG 50H

MAIN: MOV R1, #10H
CALL DISPLAY

MOV P0, #0FFH ;SET PORT 0 AS INPUT

GET00: MOV A, P0
ANL A, #00000011B
CJNE A, #00H, GET00

DIRECTION: MOV A, P0
ANL A, #00000011B
CJNE A, #01H, NEXT ; CHECK CHANNEL A = 1
JMP CW ; JUMP TO CLOCKWISE

NEXT: CJNE A, #02H, DIRECTION ; CHECK CHANNEL B = 1
JMP CCW ; JUMP TO ANTI-CLOCKWISE

CW: INC R1 ; INCREMENT R1
CJNE R1, #1AH, NEXT1 ; CHECK COUNT = 10
JMP MAIN ; LOOP BACK TO RESET COUNT


CCW: DEC R1 ; DECREMENT R1
CJNE R1, #10H, NEXT1 ; CHECK COUNT = 0
CJNE R1, #1FH, NEXT2
JMP MAIN ; LOOP BACK TO RESET COUNT

NEXT1: CALL DISPLAY ; CALL FOR DISPLAY SUBROUTINE
JMP GET00 ; LOOP BACK TO READ AGAIN

NEXT2: MOV R1, #19H
CALL DISPLAY
JMP GET00


DISPLAY: MOV P1, R1
CALL DELAY
RET

DELAY: MOV R5, #35H
F: MOV R4, #07H
E: MOV R3, #0FFH
D: DJNZ R3, D
DJNZ R4, E
DJNZ R5, F
RET
END