54xx.c

一个完整的C语言构架的串行口通信的源程序

/*****************************************************************************/
/* 54xx.c   v1.00                                                            */
/* Copyright (c) 2003	8511                    							 */
/*****************************************************************************/
#include "54xx.h"
void disable()	/*屏蔽全局中断*/
{
	asm("	SSBX INTM");
}

void enable()	/*使能全局中断*/
{
	asm("	RSBX INTM");
}

void InitPLL(unsigned int s)  		/* sets up PLL  */
{	
	CLKMD=0;             	/* set to DIV mode */
	while((CLKMD&1)==1);   /* wait until PLLstatus reflects DIV mode */
	CLKMD=s;          		/* set to multipler of s and max count cycles, turn on PLL */
	while((CLKMD&1)==0);   /* wait until PLLstatus reflects in PLL mode */
}