clock - ask

$MOD52
ORG 00H
    JMP START
    
ORG 0BH
CALL PRZERW
reti

ORG 1BH
CALL PRZERW2
reti


START:
    MOV R0, #00H
    MOV R1, #10H
    MOV R2, #20H
    MOV R3, #30H
    
    MOV R5, #00H
    MOV R6, #00H
    
    MOV TMOD, #11H
    
    SETB EA
    SETB ET0
    SETB ET1
    SETB TR0
    SETB TR1

    
SHOW:    
    MOV P2, R0
    CALL DELAY
    MOV P2, R1
    CALL DELAY
    MOV P2, R2
    CALL DELAY
    MOV P2, R3
    CALL DELAY
    JMP SHOW

    
PRZERW:
    INC R6
    CJNE R6, #30, Z
    MOV R6, #0

    INC R0

    CJNE R0, #10, Z
    MOV R0, #00H
    INC R1

    CJNE R1, #16H,Z
    MOV R1, #10H
    
Z:
RET


PRZERW2:
    INC R5
    CJNE R5, #15, Z
    MOV R5, #0

    INC R2

    CJNE R2, #2AH, Z
    MOV R2, #20H
    INC R3

    CJNE R3, #36H,Z
    MOV R3, #30H
    RET


DELAY:
    MOV R7, #255
    DJNZ R7, $
    RET
    
    
END