用51单片机输出pwm,周期不变,改变占空比答:;这是呼吸灯的程序,PWM从P0.0输出 ORG 00H SJMP MAIN ORG 000BH LJMP TIME0 ORG 001BH JMP TI个ME1 ORG 0030H MAIN:MOV SP,#70H MOV TMOD,#21H MOV 30H,#50 MOV R7,30H MOV R6,#100 MOV TL0 ,#LOW(65536-15000)MOV TH0,#HIGH(65536-15000)MOV TL1,#(256-200)MOV TH1,#(...