大家帮我看看这个51汇编程序

ORG 0000H LJMP MAIN ORG 0003H LJMP X0_INT ORG 000BH LJMP T0_INTMAIN: SETB EX0 SETB IT0 SETB TR0 SETB ET0 SETB EA MOV TMOD,#01H MOV TH0, #3CH MOV TL0, #0B0H MOV R7, #20 MOV A, #1;--------------------------------LOOP: JB 28H, _RR_RL: RL A SJMP OUT_RR: RR A;--------------------OUT: MOV P1, A CJNE R7, #0, $ MOV R7, #20 SJMP LOOP;--------------------------------T0_INT: MOV TH0, #3CH MOV TL0, #0B0H DEC R7 RETI;--------------------------------X0_INT: CPL 28H RETI;-------------------------------- END 上述程序，经过PROTEUS仿真，正确无误。 收起