dram.c

来自「三星s3c2460开发板完整功能测试代码」· C语言 代码 · 共 40 行

#include "type.h"
#include "Option.h"
#include "2460addr.h"
#include "DRAM.h"

void PreChangeSDRAMParameter(void)
{
	SetP1REFRESH(0x20);
	SetP2REFRESH(0x20);

	SetP1PARAMETER( 0xf, 0xf, 0x3, 0x3);
	SetP2PARAMETER( 0xf, 0xf, 0x3, 0x3);
}

void ChangeSDRAMParameter(unsigned int hclk)
{
	uint32 ras,rc,rcd,rp;
	
	ras = (hclk/1000*P1_tRAS-1)/1000000;
	rc = (hclk/1000*P1_tRC-1)/1000000;
	rcd = (hclk/1000*P1_tRCD-1)/1000000;
	rp = (hclk/1000*P1_tRP-1)/1000000;
	
	if(ras > 0xb)
		ras = 0xb;
	if(rc > 0xf)
		rc = 0xf;
	if(rcd > 0x3)
		rcd = 0x3;
	if(rp > 0x3)
		rp = 0x3;
	
	SetP1REFRESH(hclk/1000*P1_tREFRESH/100000);
	SetP2REFRESH(hclk/1000*P2_tREFRESH/100000);

	SetP1PARAMETER(ras, rc, rcd, rp);
	SetP2PARAMETER(ras, rc, rcd, rp);
}