STM32使用FSMC控制NAND flash 例程
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近几天开发项目需要用到STM32驱动NAND FLASH,但由于开发板例程以及固件库是用于小页(512B),我要用到的FLASH为1G bit的大页(2K),多走了两天弯路。以下笔记将说明如何将默认固件库修改为大页模式以驱动大容量NAND,并作驱动。
本文硬件:控制器:STM32F103ZET6,存储器:HY27UF081G2A
首先说一下NOR与NAND存储器的区别,此类区别网上有很多,在此仅大致说明:
1、Nor读取速度比NAND稍快
2、Nand写入速度比Nor快很多
3、NAND擦除速度(4ms)远快于Nor(5s)
4、Nor 带有SRAM接口,有足够的地址引脚来寻址,可以很轻松的挂接到CPU地址和数据总线上,对CPU要求低
5、NAND用八个(或十六个)引脚串行读取数据,数据总线地址总线复用,通常需要CPU支持驱动,且较为复杂
6、Nor主要占据1-16M容量市场,并且可以片内执行,适合代码存储
7、NAND占据8-128M及以上市场,通常用来作数据存储
8、NAND便宜一些
9、NAND寿命比Nor长
10、NAND会产生坏块,需要做坏块处理和ECC
更详细区别请继续百度,以上内容部分摘自神舟三号开发板手册
下面是NAND的存储结构:
正如硬盘的盘片被分为磁道,每个磁道又分为若干扇区,一块nand flash也分为若干block,每个block分为如干page。一般而言,block、page之间的关系随着芯片的不同而不同。
需要注意的是,对于flash的读写都是以一个page开始的,但是在读写之前必须进行flash的擦写,而擦写则是以一个block为单位的。
我们这次使用的HY27UF081G2A其PDF介绍:
Memory Cell Array
= (2K+64) Bytes x 64 Pages x 1,024 Blocks
由此可见,该NAND每页2K,共64页,1024块。其中:每页中的2K为主容量Data Field,64bit为额外容量Spare Field。Spare Field用于存贮检验码和其他信息用的,并不能存放实际的数据。由此可算出系统总容量为2K*64*1024=134217728个byte,即1Gbit。
NAND闪存颗粒硬件接口:
软件驱动:(此部分写的是伪码,仅用于解释含义,可用代码参见附件)
主程序:
#define BUFFER_SIZE 0x2000 //此部分定义缓冲区大小,即一次写入的数据
#define NAND_HY_MakerID 0xAD //NAND厂商号
#define NAND_HY_DeviceID 0xF1 //NAND器件号
/*配置与SRAM连接的FSMC BANK2 NAND*/
NAND_Init();
/*读取Nand Flash ID并打印*/
NAND_ReadID(&NAND_ID);
Tips:NAND器件的ID包含四部分:
1st Manufacturer Code
2nd Device Identifier
3rd Internal chip number, cell Type, Number of Simultaneously Programmed
pages.
4th Page size, spare size, Block size, Organization
if((NAND_ID.Maker_ID == NAND_HY_MakerID) && (NAND_ID.Device_ID == NAND_HY_DeviceID)) //判断器件符合
{
/*设置NAND FLASH的写地址*/
WriteReadAddr.Zone = 0x00;
WriteReadAddr.Block = 0x00;
WriteReadAddr.Page = 0x05;
/*擦除待写入数据的块*/
status = NAND_EraseBlock(WriteReadAddr);//写入前必须擦出
/*将写Nand Flash的数据BUFFER填充为从0x25开始的连续递增的一串数据 */
Fill_Buffer(TxBuffer, BUFFER_SIZE , 0x25);//填充数据以测试
/*将数据写入到Nand Flash中。WriteReadAddr:读写的起始地址*/
status = NAND_WriteSmallPage(TxBuffer, WriteReadAddr, PageNumber); //主要写入函数,此部分默认为小页需要修改
/*从Nand Flash中读回刚写入的数据。?riteReadAddr:读写的起始地址*/
status = NAND_ReadSmallPage (RxBuffer, WriteReadAddr, PageNumber); //读取主要函数,也需要修改
/*判断读回的数据与写入的数据是否一致*/
for(j = 0; j < BUFFER_SIZE; j++)
{
if(TxBuffer[j] != RxBuffer[j])
{
WriteReadStatus++;
}
}
if (WriteReadStatus == 0)
{
printf("nr Nand Flash读写访问成功");
GPIO_ResetBits(GPIO_LED, DS2_PIN);
}
else
{
printf("nr Nand Flash读写访问失败");
printf("0x%x",WriteReadStatus);
GPIO_ResetBits(GPIO_LED, DS3_PIN);
}
}
else
{
printf("nr 没有检测到Nand Flash的ID");
GPIO_ResetBits(GPIO_LED, DS4_PIN);
}
fsmc_nand.c文件:
void NAND_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
FSMC_NAND_PCCARDTimingInitTypeDefp;
FSMC_NANDInitTypeDef FSMC_NANDInitStructure;
/*FSMC总线使用的GPIO组时钟使能*/
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE |
RCC_APB2Periph_GPIOF | RCC_APB2Periph_GPIOG, ENABLE);
/*FSMC CLE, ALE, D0->D3, NOE, NWE and NCE2初始化,推挽复用输出*/
GPIO_InitStructure.GPIO_Pin =GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_14 | GPIO_Pin_15 |
GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_4 | GPIO_Pin_5 |
GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/*FSMC数据线FSMC_D[4:7]初始化,推挽复用输出*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;
GPIO_Init(GPIOE, &GPIO_InitStructure);
/*FSMC NWAIT初始化,输入上拉*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOD, &GPIO_InitStructure);
/*FSMC INT2初始化,输入上拉*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOG, &GPIO_InitStructure);
/*--------------FSMC 总线 存储器参数配置------------------------------*/
p.FSMC_SetupTime = 0x1; //建立时间
p.FSMC_WaitSetupTime = 0x3; //等待时间
p.FSMC_HoldSetupTime = 0x2; //保持时间
p.FSMC_HiZSetupTime = 0x1; //高阻建立时间
FSMC_NANDInitStructure.FSMC_Bank = FSMC_Bank2_NAND; //使用FSMC BANK2
FSMC_NANDInitStructure.FSMC_Waitfeature = FSMC_Waitfeature_Enable; //使能FSMC的等待功能
FSMC_NANDInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_8b; //NAND Flash的数据宽度为8位
FSMC_NANDInitStructure.FSMC_ECC = FSMC_ECC_Enable; //使能ECC特性
FSMC_NANDInitStructure.FSMC_ECCPageSize = FSMC_ECCPageSize_2048Bytes; //ECC页大小2048
FSMC_NANDInitStructure.FSMC_TCLRSetupTime = 0x00;
FSMC_NANDInitStructure.FSMC_TARSetupTime = 0x00;
FSMC_NANDInitStructure.FSMC_CommonSpaceTimingStruct = &p;
FSMC_NANDInitStructure.FSMC_AttributeSpaceTimingStruct = &p;
FSMC_NANDInit(&FSMC_NANDInitStructure);
/*!使能FSMC BANK2 */
FSMC_NANDCmd(FSMC_Bank2_NAND, ENABLE);
}
void NAND_ReadID(NAND_IDTypeDef* NAND_ID)
{
uint32_t data = 0;
/*!< Send Command to the command area */
*(__IO uint8_t *)(Bank_NAND_ADDR | CMD_AREA) = 0x90;
*(__IO uint8_t *)(Bank_NAND_ADDR | ADDR_AREA) = 0x00;
/*!< Sequence to read ID from NAND flash */
data = *(__IO uint32_t *)(Bank_NAND_ADDR | DATA_AREA);
NAND_ID->Maker_ID = ADDR_1st_CYCLE (data);//四个周期读取四个ID
NAND_ID->Device_ID= ADDR_2nd_CYCLE (data);
NAND_ID->Third_ID = ADDR_3rd_CYCLE (data);
NAND_ID->Fourth_ID= ADDR_4th_CYCLE (data);
}
uint32_t NAND_WriteSmallPage(uint8_t *pBuffer, NAND_ADDRESS Address, uint32_t NumPageToWrite)
{//传入参数:写入数据,写入初始地址,要写几页
uint32_t index = 0x00, numpagewritten = 0x00, addressstatus = NAND_VALID_ADDRESS;
uint32_t status = NAND_READY, size = 0x00;
while((NumPageToWrite != 0x00) && (addressstatus == NAND_VALID_ADDRESS) && (status == NAND_READY))
{
/*!< Page write command and address */
*(__IO uint8_t *)(Bank_NAND_ADDR | CMD_AREA) = NAND_CMD_AREA_A;
*(__IO uint8_t *)(Bank_NAND_ADDR | CMD_AREA) = NAND_CMD_WRITE0;
*(__IO uint8_t *)(Bank_NAND_ADDR | ADDR_AREA) = 0x00;
*(__IO uint8_t *)(Bank_NAND_ADDR | ADDR_AREA) = 0x00;//添加此句
*(__IO uint8_t *)(Bank_NAND_ADDR | ADDR_AREA) = ADDR_1st_CYCLE(ROW_ADDRESS);
*(__IO uint8_t *)(Bank_NAND_ADDR | ADD