求救Atmega16的快速PWM模式

只看该作者 · 2012-4-14 14:16

芯片资料上的模式14，top值是ICR1，想用OC1B输出，需要设置什么top清零吗？我想用固定top值来控制舵机，50Hz频率，8分频，比较匹配时置位，TCCR1A:0x32
TCCR1B:0x1A
ICR1H=0x4e
ICR1l=0x1F
OCR1B 控制占空比

这么配置怎么总是不行？我用ICCAVR自动向导也控制不了，是不是这个模式不能产生50Hz的频率啊？
先谢谢各位大神了哈

只看该作者 · 2012-4-14 14:44

都已经进来的大神们，赐教一下吧

只看该作者 · 2012-4-15 18:25

//ICC-AVR application builder : 2012-4-15 18:25:09
// Target : M16
// Crystal: 8.0000Mhz

#include <iom16v.h>
#include <macros.h>

void port_init(void)
{
PORTA = 0x00;
DDRA  = 0x00;
PORTB = 0x00;
DDRB  = 0x00;
PORTC = 0x00; //m103 output only
DDRC  = 0x00;
PORTD = 0x00;
DDRD  = 0x00;
}

//TIMER1 initialize - prescale:8
// WGM: 14) PWM fast, TOP=ICRn
// desired value: 50Hz
// actual value: 50.000Hz (0.0%)
void timer1_init(void)
{
TCCR1B = 0x00; //stop
TCNT1H = 0xB1; //setup
TCNT1L = 0xE1;
OCR1AH = 0x4E;
OCR1AL = 0x1F;
OCR1BH = 0x4E;
OCR1BL = 0x1F;
ICR1H  = 0x4E;
ICR1L  = 0x1F;
TCCR1A = 0x32;
TCCR1B = 0x1A; //start Timer
}

//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
timer1_init();

MCUCR = 0x00;
GICR  = 0x00;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialized
}