第3题:
MCS-51单片机采用12MHz的晶振,定时器T1为软启动,用作定时方式,采用工作方式1,则方式寄存器TMOD的值为()
A.0x01
B.0x10
C.0x20
D.0x50
(1) (4分) TH0=(65536-30000)/256; TL0=(65536-30000)%256; (2) (6分) TMOD=0x01; TCON=0x10; IE=0X82 (3) (10分,按程序实现情况给分) #include sbit P1_0=P1^0; void timer0 (void) interrupt 1 { P1_0 = !P1_0; //P1.0取反 TH0 =(65536-30000)/256; //计数初值重装载 TL0 = (65536-30000)%256; } void main (void) { TMOD = 0x01; //T0定时方式1 P1_0=0; TH0=(65536-30000)/256; //预置计数初值 TL0=(65536-30000)%256; EA=1; ET0=1; TR0=1; while (1); }