atmega8 example: T1 timer CTC mode square wave output

/*******************************************************************

* Function library description: ATMEGA8 T1 timer CTC mode square wave output

* Version: v1.00        

* Edited by: Pang Hui, Wuhu Lianda Freescale Studio                     

* Modified on: August 8, 2011    

*        

* Description: OC1A changes the logic level every time a comparison match occurs, that is, a square wave output with a frequency of 50% 2ms

* At this time, OC1A should be set to output

*                                                          

* Version update: See readme.txt for details

*

* 20110805 V1.02                                            

*                                                                                          

********************************************************************

*Note: When used as a square wave output, whether OCR1A or ICR1 is used as the TOP value, the output pin is OC1A

* 6M external crystal

********************************************************************/

#include

int main(void)

{

    //OC1A is set to output. When used as a square wave output, it must be set to output

    DDRB |= (1 << PB1);

    //6M crystal oscillator 8-frequency division 1ms level inversion once, that is, square wave frequency 2ms

    //OCR1A = 750;

    ICR1 = 750;

    //OC1A match inversion

    TCCR1A |= (1 << COM1A0);

    //CTC OCR1A mode, 8-division 6M / 8 = 750khz and start CTC mode

    //TCCR1B |= (1 << WGM12) | (1 << CS11);

    TCCR1B |= (1 << WGM13) | (1 << WGM12) | (1 << CS11);

    while(1);

    return 0;

}