pwm.c

采用nios2的嵌入式数字钟的设计与实现

#include <stdio.h>
#include "altera_avalon_pwm.h"
#include "system.h"

int main()
{ 
	int rx_char;
	char line[100];
	
  printf("Hello from Nios II!\n");
  printf("Nios II Training Lab\n");
  printf("March 18, 2003\n");
  
  printf("\nPlease enter an LED intensity between 1 to 4 (0 to exit)\n");
  
  IOWR_ALTERA_AVALON_PWM_DIVIDER(MY_PWM_BASE,0xFF);
  IOWR_ALTERA_AVALON_PWM_DUTY(MY_PWM_BASE,0xFF);
  
  while (1)
	{
  
	  fgets(line, sizeof(line),stdin);
	  sscanf(line,"%d",&rx_char);
	
		switch (rx_char)
		{
			case 4:
				IOWR_ALTERA_AVALON_PWM_DUTY(MY_PWM_BASE,0xFF);
				printf("Level 4 intensity\n");
				break;
	
			case 3:
				IOWR_ALTERA_AVALON_PWM_DUTY(MY_PWM_BASE,0x80);
				printf("Level 3 intensity\n");
				break;
	
			case 2:
				IOWR_ALTERA_AVALON_PWM_DUTY(MY_PWM_BASE,0x30);
				printf("Level 2 intensity\n");
				break;
	
			case 1:
				IOWR_ALTERA_AVALON_PWM_DUTY(MY_PWM_BASE,0x10);
				printf("Level 1 intensity\n");
				break;
	
			case 0:
			  return 0;
				break;
	
			default:
			  printf("Please enter an integer value from 0 to 4\n");
				break;
		}
	}
  return 0;
}