pll.c

来自「freescale最新的16位单片机」· C语言 代码 · 共 36 行

/******************************************************************************
*
* Freescale Semiconductor Inc.
* (c) Copyright 2004-2005 Freescale Semiconductor, Inc.
* ALL RIGHTS RESERVED.
*
***************************************************************************//*!
*
* @file      pll.c
*
* @author    R89994
* 
* @version   1.0.6.0
* 
* @date      Jul-28-2006
* 
* @brief     set-up bus frekvency, system clock
*
********************************************************************************/

#include "main.h"
#include "pll.h"



void SetupPLL(void)
{
  CLKSEL_PLLSEL=0;            /* System Clock = OSCCLK */
  PLLCTL = 0xE1;              /* CME, PLLON, AUTO, SCME */
  /* OSCCLK = 4MHz, PLLCLK = 48MHz, BUSCLK = 24MHz */
  REFDV = 0;                  /* REFDV = 0 */
  SYNR = 5;                   /* SYNR = 5 */
  while(!CRGFLG_LOCK);        /* Wait for PLL VCO is in desired range */
  CLKSEL_PLLSEL = 1;          /* System Clock = PLLCLK  */
}