KEYL?EQU?P1.1
LED?EQU?P0
ORG?0000H
LJMP?MAIN
ORG?000BH
LJMP?T0ISR
ORG?0030H
MAIN:
MOV?TMOD,#01H
MOV?TH0,#HIGH(65536-50000)
MOV?TL0,#LOW(65536-50000)
SETB?ET0
SETB?EA
MOV?A,#0FEH
MOV?LED,A
MOV?R2,#0
CLR?00H
LOOP:
CLR?TR0
LOOPL:
JB?KEYL,LOOPR
SETB?TR0
RL?A
MOV?LED,A
JNB?00H,$
CLR?00H
SJMP?LOOPL
LOOPR:
JB?KEYR,LOOP
SETB?TR0
RR?A
MOV?LED,A
JNB?00H,$
CLR?00H
SJMP?LOOPR
T0ISR:
CLR?TR0
MOV?TH0,#HIGH(65536-50000)
MOV?TL0,#LOW(65536-50000)
SETB?TR0
INC?R2
CJNE?R2,#20,T0E
MOV?R2,#0
SETB?00H
T0E:
RETI
END