mcf52255_sysinit.c

冷火MCF52255开发板精华资料

/*
 * File:		mcf52255_sysinit.c
 * Purpose:		Reset configuration of the MCF52255
 *
 * Notes:
 */
#include "support_common.h"
#include "exceptions.h"


/********************************************************************/
void
pll_init(void)
{
//MCF_CLOCK_CCHR =0x05; // The PLL pre divider - 48MHz / 6 = 8MHz 
    /* The PLL pre-divider affects this!!! 
             * Multiply 48Mhz reference crystal /CCHR by 10 to achieve system clock of 80Mhz
             */
    MCF_CLOCK_SYNCR = MCF_CLOCK_SYNCR_MFD(3) | MCF_CLOCK_SYNCR_CLKSRC| MCF_CLOCK_SYNCR_PLLMODE | MCF_CLOCK_SYNCR_PLLEN ;
    while (!(MCF_CLOCK_SYNSR & MCF_CLOCK_SYNSR_LOCK))
    {
    }
}
/********************************************************************/
void
scm_init(void)
{
	/*
	 * Enable on-chip modules to access internal SRAM
	 */
	MCF_SCM_RAMBAR = (0
		| MCF_SCM_RAMBAR_BA(RAMBAR_ADDRESS)
		| MCF_SCM_RAMBAR_BDE);
}
/********************************************************************/
void __initialize_hardware(void)
{
	/*******************************************************
	*	Out of reset, the low-level assembly code calls this 
	*	routine to initialize the MCF52255 modules.
	********************************************************/

	asm 
	{
	    /* Initialize IPSBAR */
	    move.l  #__IPSBAR,d0
	       andi.l  #0xC0000000,d0 // need to mask
	    add.l   #0x1,d0
	    move.l  d0,0x40000000

	    

	    /* Initialize FLASHBAR */
	    move.l  #__FLASHBAR,d0
	       andi.l  #0xFFF80000,d0 // need to mask
	    add.l   #0x61,d0
	    movec   d0,FLASHBAR

	}
   	
	
	pll_init();
	scm_init();	

	initialize_exceptions();
}