说明：
根据物理结构上的区别 , NandFlash主要分为如下两类:1）•SLC (Single Level Cell): 单层式存储2）•MLC (Multi Level Cell): 多层式存储@：SLC在存储格上只存一位数据， 而MLC则存放两位数据。
1.nand.c
#define NFCONF (*(volatile unsigned long*)0x4E000000)#define NFCONT (*(volatile unsigned long*)0x4E000004)#define NFCMD (*(volatile unsigned char*)0x4E000008)#define NFADDR (*(volatile unsigned char*)0x4E00000C)#define NFDATA (*(volatile unsigned char*)0x4E000010)#define NFSTAT (*(volatile unsigned char*)0x4E000020)#define TACLS 1#define TWRPH0 2#define TWRPH1 1void select_chip(){ NFCONT &= ~(1<<1); }void deselect_chip(){ NFCONT |= (1<<1); }void clear_RnB(){ NFSTAT |= (1<<2); }void send_cmd(unsigned cmd){ NFCMD = cmd;}void send_addr(unsigned addr){ NFADDR = addr;}void wait_RnB(){ while (!(NFSTAT&(1<<2))) { ; }}void nand_reset(){ //选中flash select_chip(); //清除RnB clear_RnB(); //发送0xff命令 send_cmd(0xff); //等待RnB wait_RnB(); //取消选中flash deselect_chip();}void nandflash_init(){ //初始化NFCONF NFCONF = (TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4); //初始化NFCONT NFCONT = (1<<0) | (1<<1); //复位 nand_reset(); }void NF_PageRead(unsigned long addr,unsigned char* buff){ int i; //选中nandflash芯片 select_chip(); //清除RnB clear_RnB(); //发送命令0x00 send_cmd(0x00); //发送列地址 send_addr(0x00); send_addr(0x00); //发送行地址 send_addr(addr&0xff); send_addr((addr>>8)&0xff); send_addr((addr>>16)&0xff); //发送命令0x30 send_cmd(0x30); //等待RnB wait_RnB(); //读取数据 for(i=0;i<2048;i++) { buff[i] = NFDATA; } //取消选中nandflash芯片 deselect_chip();}void nand_to_ram(unsigned long start_addr, unsigned char* sdram_addr, int size){ int i; for( i=(start_addr >>11); size>0;) { NF_PageRead(i,sdram_addr); size -= 2048; sdram_addr += 2048; i++; }}int NF_Erase(unsigned long addr){ int ret; //选中flash芯片 select_chip(); //清除RnB clear_RnB(); //发送命令0x60 send_cmd(0x60); //发送行地址 send_addr(addr&0xff); send_addr((addr>>8)&0xff); send_addr((addr>>16)&0xff); //发送命令D0 send_cmd(0xD0); //等待RnB wait_RnB(); //发送命令0x70 send_cmd(0x70); //读取擦除结果 ret = NFDATA; //取消选中flash芯片 deselect_chip(); return ret; }int NF_WritePage(unsigned long addr,unsigned char *buff){ unsigned int i,ret = 0; //选中nandflash select_chip(); //清除RnB clear_RnB(); //发送0x80命令 send_cmd(0x80); //发送2个列地址 send_addr(0x00); send_addr(0x00); //发送3个行地址 send_addr(addr&0xff); send_addr((addr>>8)&0xff); send_addr((addr>>16)&0xff); //发送数据 for(i=0;i<2048;i++) { NFDATA = buff[i]; } //发送0x10命令 send_cmd(0x10); //等待RnB wait_RnB(); //发送0x70命令 send_cmd(0x70); //读取写入结果 ret = NFDATA; //关闭nandflash deselect_chip(); return ret; }
2.uart.c
#define GPHCON (*(volatile unsigned long*)0x56000070)#define ULCON0 (*(volatile unsigned long*)0x50000000)#define UCON0 (*(volatile unsigned long*)0x50000004)#define UBRDIV0 (*(volatile unsigned long*)0x50000028)#define UTRSTAT0 (*(volatile unsigned long*)0x50000010)#define UTXH0 (*(volatile unsigned long*)0x50000020)#define URXH0 (*(volatile unsigned long*)0x50000024)#define PCLK 50000000#define BAUD 115200void uart_init(){ //1.配置引脚功能 GPHCON &= ~(0xf<<4); GPHCON |= (0xa<<4); //2.1 设置数据格式 ULCON0 = 0b11; //2.2 设置工作模式 UCON0 = 0b0101; //3. 设置波特率 UBRDIV0 =(int)(PCLK/(BAUD*16)-1);}void putc(unsigned char ch){ while (!(UTRSTAT0 & (1<<1))); UTXH0 = ch; }unsigned char getc(void){ unsigned char ret; while (!(UTRSTAT0 & (1<<0))); // 取数据 ret = URXH0; if ( (ret == 0x0d) || (ret == 0x0a) ) { putc(0x0d); putc(0x0a); } else putc(ret); return ret;}