LCD DMA day59

最新推荐文章于 2026-01-06 10:52:03 发布

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#arm开发

十四：LCD 显示屏

一：基础概念

访问：

1.传输bank地址和行地址

2传输列地址及读写信号

3．写：写数据到DATA（先写到数据总线中，再数据操作）

读： (先数据操作，再从数据总线拿出数据)从DATA获取数据

二：代码

#include "lcd.h"
#include <s3c2440.h>

void lcd0_init(void)
{
	//引脚
	GPCCON |= 0xffff;
	GPCCON = 0xaaaaaaaa;
	GPDUP  |= 0xffff;
	GPDCON = 0xaaaaaaaa;		
	//LCDCON1
	LCDCON1 |= (7 << 8) | (0x3 << 5) | (0xc << 1);

	//LCDCON2
	LCDCON2 |= (13 << 24) | (319 << 14);

	//LCDCON3
	LCDCON3 |= (80 << 19) | (239 << 8);

	//LCDCON5
	LCDCON5 |= (1 << 11) |(1 << 10) | (1 << 3);

	//LCDSADDR
	LCDSADDR1 | FRAMEBUFFER >> 1;
	LCDSADDR2 = (LCDSADDR1 & 0x1fffff) + 240*320;

	//最终使能
	LCDCON1 |= (0x1<< 0);
}

void display_point(int x, int y, unsigned short col)
{
	*((unsigned short *)FRAMEBUFFER+y*240+x) = col;
}

void clear(unsigned short col)
{
	int i = 0;
	int j = 0;
	for(i = 0; i < 320; i++)
	for(j = 0; j < 240; j++)
	display_point(j, i, col);
}


-----------------------------------------------------
     clear(0xf800);
	display_point(120, 160, 0);
	display_point(125, 160, 0);
	display_point(120, 165, 0);
	display_point(125, 165, 0);

十五：DMA

从内存空间操作的，所以是AHB

#include "dma.h"
#include <s3c2440.h>

void dma_init(void)
{
	DISRCC1 &= ~(0x3 << 0);	  	//AHB  增加
	DIDST1  &= ~(0x3 << 0);		//AHB  增加 
	
	DCON1 |= (1 << 31) | (1 << 30) | (1 << 27)
	       | (1 << 22) | (0x2 << 20);
	
	DSTAT1 = 0;		
}
void memcpy(unsigned long * dest,unsigned long * src,int len)
{
	unsigned char i = 0;
	DISRC1 &= ~(0x3fffffff << 0);
	DISRC1 = (unsigned long)src;
	DIDST1 &= ~(0x3fffffff << 0);
	DIDST1 = (unsigned long)dest;

	DCON1 &= ~(0xfffff << 0);
	DCON1 |= (len << 0);

	DMASKTRIG1 |= (1 << 1) | (1 << 0);

	while((DSTAT1 & (1 << 20)));
}