用定时器0，方式二在IO口线上产生500ms的方波（汇编）

ORG 0000H
STARE: LJMP MAIN
ORG 000BH
LJMP TTC0
ORG 0100H
MAIN: MOV SP, #5FH
MOV TMOD, #02H
SETB EA
SETB ET0
MOV TH0,#00H
MOV TL0,#06H
SETB TR0
MOV R0, #200
MOV R1, #10
HERE: LJMP HERE
TTC0: DJNZ R0, LOOP0
DJNZ R1, LOOP1
CPL P3.0
MOV R0, #200
MOV R1, #10
LOOP0: RETI
LOOP1: MOV R0, #200
LJMP LOOP0
END