void init_tc1_pwm(void)
{
	OCR1AL=OCR1BL=125;
	PORTB|=(1<<PB1)|(1<<PB2);
	TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<COM1A0)|(1<<COM1B0)|(1<<WGM10);//上升沿匹配清零8位相位可調(diào)PWM
	TCCR1B|=(1<<CS10);//系統(tǒng)時(shí)鐘
}