ORG 0000H
JMP MAIN
ORG 000BH
JMP T0INT
MAIN:MOV A,#0FEH ;若LED為高電平觸發(fā)則為01H
MOV R0,#0
MOV TMOD,#01H
MOV TH0,#(65536-50000)/256 ;12M晶振50000個時鐘周期,50ms
MOV TL0,#(65536-50000)MOD 256
SETB ET0
SETB EA
SETB TR0
SJMP $
T0INT:INC R0
CJNE R0,#20,L ;循環(huán)20次,即1s,執(zhí)行下面語句
MOV P1,A
RL A ;將計數(shù)器A中數(shù)字循環(huán)左移
MOV R0,#0 ;將R0復位
L:MOV TH0,#(65536-50000)/256
MOV TL0,#(65536-50000)MOD 256
RETI
END
|