KEY0 BIT P1.0
KEY1 BIT P1.1
KEY2 BIT P1.2
LED0 BIT P1.4
LED1 BIT P1.5
LED2 BIT P1.6
ORG 0000H
LJMP MAIN
ORG 0030H
MAIN:
JB KEY0,MAIN1
CLR LED0
SJMP MAIN
MAIN1:
SETB LED0
JB KEY1,MAIN2
CLR LED1
SJMP MAIN
MAIN2:
SETB LED1
JB KEY2,MAIN3
CLR LED2
SJMP MAIN
MAIN3:
SETB LED2
SJMP MAIN
END