nand_flsha程序

#define BUSY 1
#define NAND_SECTOR_SIZE_LP 2048
#define NAND_BLOCK_MASK_LP (NAND_SECTOR_SIZE_LP - 1)
#define uint unsigned int
typedef struct {
uint NFCONF;
uint NFCONT;
uint NFCMD;
uint NFADDR;
uint NFDATA;
uint NFMECCD0;
uint NFMECCD1;
uint NFSECCD;
uint NFSTAT;
uint NFESTAT0;
uint NFESTAT1;
uint NFMECC0;
uint NFMECC1;
uint NFSECC;
uint NFSBLK;
uint NFEBLK;
} S3C2440_NAND;
static S3C2440_NAND * s3c2440nand = (S3C2440_NAND *)0x4e000000;
static void s3c2440_nand_reset(void);
static void s3c2440_wait_idle(void);
static void s3c2440_nand_select_chip(void);
static void s3c2440_nand_deselect_chip(void);
static void s3c2440_write_cmd(int cmd);
static void s3c2440_write_addr_lp(unsigned int addr);
static unsigned char s3c2440_read_data(void);
static void s3c2440_nand_reset(void){
s3c2440_nand_select_chip();
s3c2440_write_cmd(0xff); // 复位命令
s3c2440_wait_idle();
s3c2440_nand_deselect_chip();
}
static void s3c2440_wait_idle(void){
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFSTAT;
while(!(*p & BUSY))
for(i=0; i<10; i++);
}
static void s3c2440_nand_select_chip(void){
int i;
s3c2440nand->NFCONT &= ~(1<<1);
for(i=0; i<10; i++);
}
static void s3c2440_nand_deselect_chip(void){
s3c2440nand->NFCONT |= (1<<1);
}
static void s3c2440_write_cmd(int cmd){
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFCMD; //取地址
*p = cmd;
}
static void s3c2440_write_addr_lp(unsigned int addr) //大页的NAND FLASH . {
int i;
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand->NFADDR; int col, page;
col = addr & NAND_BLOCK_MASK_LP;
page = addr / NAND_SECTOR_SIZE_LP;
*p = col & 0xff; /* Column Address A0~A7 */
for(i=0; i<10; i++);
*p = (col >> 8) & 0x0f; /* Column Address A8~A11 */
for(i=0; i<10; i++);
*p = page & 0xff; /* Row Address A12~A19 */
for(i=0; i<10; i++);
*p = (page >> 8) & 0xff; /* Row Address A20~A27 */
for(i=0; i<10; i++);
*p = (page >> 16) & 0x03; /* Row Address A28~A29 */
for(i=0; i<10; i++);
}
static unsigned char s3c2440_read_data(void)
{
volatile unsigned char *p = (volatile unsigned char *)&s3c2440nand-
>NFDATA;
return *p;
}
void nand_init(void)
{
#define TACLS 0 //0x00 13:12
#define TWRPH0 3 //0x011 10:8
#define TWRPH1 0 //0x00 6:5:4
s3c2440nand->NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);
s3c2440nand->NFCONT = (1<<4)|(1<<1)|(1<<0); // (使能ECC)(禁止片选)（寄存器不使能）
s3c2440_nand_reset();
}
void nand_read(unsigned char *buf, unsigned long start_addr, int size)
{
int i,j;
if ((start_addr & NAND_BLOCK_MASK_LP) || (size &
NAND_BLOCK_MASK_LP))
{
return ; /* 地址或长度不对齐 */
}
s3c2440_nand_select_chip();
for(i=start_addr; i < (start_addr + size);)
{
s3c2440_write_cmd(0);
s3c2440_write_addr_lp(i);
s3c2440_write_cmd(0x30);
s3c2440_wait_idle();
for(j=0; j < NAND_SECTOR_SIZE_LP; j++, i++)
{
*buf=s3c2440_read_data();
buf++;
}
}
s3c2440_nand_deselect_chip();
return ;
}。