pwm.c

来自「嵌入式系统mcf5272华恒光盘开发板附源代码pwm」· C语言 代码 · 共 38 行

/*
 *File:			Pwm.c
 *Purpose:		Initialize the PWM(Pulse Width Modulation) Module
 *
 *Notes:		Assume that thers is a LED linked to the output pins		
 */


#define MCF5272_PWM_PWMCR1 (0x0C0)
#define MCF5272_PWM_PWWD1 (0x0d0)
#define MCF5272_MBAR      0x10000000
#include <stdio.h>

main()
{
	
	if( getchar() == '1')
	{
	 	
		//disable the pwm,and output is low 
		*(volatile unsigned char *)(MCF5272_MBAR + MCF5272_PWM_PWMCR1) = 0x04;
		usleep(2000000); 
		//disable the pwm,and output is high	
		*(volatile unsigned char *)(MCF5272_MBAR + MCF5272_PWM_PWMCR1) = 0x24;	 

	}else 
	{
	  	//enable the pwm,and output is half high
		*(volatile unsigned char *)(MCF5272_MBAR + MCF5272_PWM_PWWD1) = 0x80;
		*(volatile unsigned char *)(MCF5272_MBAR + MCF5272_PWM_PWMCR1) = 0xA0;
		  	  
	}
	printf("OK\n");
	
}