led.c

codewarrior dsp 56807 中断编程实现灯闪烁,有详细的注释

/*  metrowerks sample code  */



/*
	this source illustrates code called by ISR 
	and #pragma directives necessary for ISR-safe code
		
*/



#include "DSP56F807.h"
#include "led.h"

/* libraries called by interrupt handlers need this pragma, it will:
1. save used register
2. return with RTS instead of RTI */
#pragma interrupt called

void initLED()
{  //////111111111111111111111111
	/* disable SSI peripheral   */
	asm(bfclr	#$0001,X:GPIO_B_PER);  /// 0001
	asm(bfclr	#$0002,X:GPIO_B_PER);  /// 0010
	asm(bfclr	#$0004,X:GPIO_B_PER);  /// 0100
	
	/* output direction  输出方向定义  */
	asm(bfset	#$0001,X:GPIO_B_DDR); ////  0001 GPIO_B_DDR 为寄存器 B