【GD32F303红枫派使用手册】第二十节 SPI-SPI NAND FLASH读写实验

20.1 实验内容

通过本实验主要学习以下内容：

SPI通信协议，参考19.2.1东方红开发板使用手册

GD32F303 SPI操作方式，参考19.2.2东方红开发板使用手册

NAND FLASH基本原理

SPI NAND介绍

使用GD32F303 SPI接口实现对GD5F1GQ5UEYIGY的读写操作

20.2 实验原理

20.2.1 NAND FLASH基本原理

NAND Flash和NOR Flash都是两种非易失性存储器，其读写速度、读写方式，存储区结构、成本、容量、擦写寿命都有很大区别。NAND在寿命、速度、读写方式上都不如NOR，但在成本和容量上有很大区别，故而决定了大容量数据存储是NAND的主要应用领域，而快速启动、快速数据读取等场景是NOR的主要应用领域。而SPI是目前NAND和NOR的主要通信接口形式，降低了器件体积，标准化了器件接口。

NAND Flash结构示例

如上图所示，以GD5F1GQ5UEYIGY为例，一个1Gb的存储结构下是由1024个block组成，每个block又64page组成，每个page是2K Main Area+Spare Area(ECC ON:64B;ECC OFF:128B)组成。

NAND的擦除单位是blocks，写入单位是page，所以寻址的方式上和nor是有本质区别的，需要按blocks、page、page字节偏移地址进行一个数据的寻址。

20.2.2 SPI NAND介绍

SPI NAND简化了NAND的接口设计和尺寸，SPI接口更是降低了主控对接口的要求，同时内置ECC。下图是GD5F1GQ5UEYIGY的命令表，常用的命令为擦除、编程、读取命令。

block擦除命令
编程
编程流程

先用数据缓存写入指令将数据写入缓冲区

然后发送写使能命令，并确认写使能成功

然后发送数据载入命令执行缓冲区数据到FLASH的写

最后查询读寄存器确认P_FAIL是否有错，OIP是否完成

注意(84h/C4h/34h) 和(FFh) 指令是不会清除缓存中的内容的，所以下次编程时要注意是否缓存区都是需要更新的数据，所以必须是一次更新整个缓冲区，不要部分更新。

编程page地址按照块的顺序

数据缓存写入命令

数据载入命令

读取

读取流程

读需要先通过读cache命令从FLASH中读出数据到缓存中

然后通过读cache指令从缓冲区中开始读出数据

读到2048+128后绕回从0开始继续。

20.3 硬件设计

红枫派开发板SPI——NAND FLASH的硬件设计如下：

从图中可以看出，本实验使用的是普通单线SPI，GD5F1GQ5UEYIGY的片选由GD32F303ZET6的PG13控制（因PG14不是SPI的NSS管脚，所以本实验用主机NSS软件模式,，通过普通IO控制片选），GD25Q32ESIGR的SO、SI和SCLK分别和GD32F303ZET6的PB4（SPI2_MISO）、PB5（SPI2_MOSI）以及PB3（SPI2_CLK）相连。

20.4 代码解析

20.4.1 SPI初始化和读写BYTE函数实现

SPI初始化配置流程可参考19.4.1东方红开发板使用手册；

SPI读写BYTE函数实现可参考19.4.2东方红开发板使用手册；

20.4.2 SPI NAND FLASH BSP驱动层实现

操作NAND FLASH的函数都定义在bsp层文件bsp_spi_nand.c中，这个文件中定义的函数都是针对NAND FLASH命令来实现的，我们选取几个函数进行介绍。

NOR FLASH按block擦除函数bsp_nandflash_block_erase，输入block号即可擦除；该函数流程是：使能NAND FLASH的写功能->向NOR FLASH发送block擦除指令0xD8->发送左移6位的Block NO->查询OIP标志等待完成

C
/*!
    \brief      erase the nandflash blcok
    \param[in]  block_No:the serial number of erase block
    \param[out] none
    \retval     SPI_NAND_FAIL: erase the nandflash block fail
    \retval     SPI_NAND_SUCCESS: erase the nandflash block success
*/
uint8_t bsp_spi_nandflash_block_erase(uint32_t block_No)
{
    uint8_t result = SPI_NAND_SUCCESS;

    block_No<<=6;        //block_No=block_No*64
    bsp_spi_nandflash_write_enable();
    /* select the flash: chip select low */
    bsp_spi_nand_cs_low();
    /* send "ERASE BLOCK" command */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,SPI_NAND_BLOCK_ERASE);
    /* send the address of memory */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(block_No>>16)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(block_No>>8)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,block_No&0xFF);
    /* deselect the flash: chip select high */
    bsp_spi_nand_cs_high();
    while(bsp_spi_nandflash_get_status_flag(OIP)==SPI_NAND_BUSY);
    /* check program result */        

    return result;
}

NOR FLASH按page写入函数bsp_nandflash_page_program，输入待写入数据指针、block号、page号；该函数流程是：

写缓冲区，实现流程：向NOR FLASH发送写缓冲区指令0x02->发送写入的page偏移地址->发送待写入数据

载入数据到page，实现流程：使能NAND FLASH的写功能->发送载入命令0x10->发送写入的page号

查询OIP标志等待完成

C
/*!
    \brief      send the program load command,write data to cache
    \param[in]  buffer: the data of array
    \param[in]  address_in_page: the address in nandflash page
    \param[in]  byte_cnt: the number of data
    \param[out] none
    \retval     none
*/
void bsp_spi_nandflash_program_load(uint8_t *buffer,uint16_t address_in_page,uint32_t byte_cnt)
{
    uint32_t i=0;

    /* select the flash: chip select low */
    bsp_spi_nand_cs_low();
#ifdef SPI_NANDFLASH
    /* send "PAGE READ" command */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,SPI_NAND_PAGE_LOAD);
    /* send the serial number of page */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(address_in_page>>8)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,address_in_page&0xFF);
#endif 
    

    /* deselect the flash: chip select high */

        
    for(i=0;i<byte_cnt;i++){
        driver_spi_master_transmit_receive_byte(&BOARD_SPI,*buffer++);
    }
    //printf("cache program %x %x\n\r",m32record[0],m32record[1]);
        
    bsp_spi_nand_cs_high();
    qspi_disable(BOARD_SPI.spi_x);
}

/*!
    \brief      send the program excute command
    \param[in]  page_No: the serial number of nandflash page
    \param[out] none
    \retval     none
*/
void bsp_spi_nandflash_program_execute(uint32_t page_No)
{
    /* enable the write access to the flash */
    bsp_spi_nandflash_write_enable();
    /* select the flash: chip select low */
    bsp_spi_nand_cs_low();
    /* send "PAGE READ" command */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,SPI_NAND_PROGRAM_EXEC);
    /* send the serial number of page */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(page_No>>16)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(page_No>>8)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,page_No&0xFF);
    /* deselect the flash: chip select high */
    bsp_spi_nand_cs_high();
}

/*!
    \brief      write the data to nandflash
    \param[in]  *buffer:the data of array
    \param[in]  page_No: the serial number of nandflash page
    \param[in]  address_in_page: the address of nandflash page
    \param[in]  byte_cnt:the number of data
    \param[out] none
    \retval     SPI_NAND_FAIL,SPI_NAND_SUCCESS 
*/
uint8_t spi_nandflash_write_data(uint8_t *buffer,uint32_t page_No,uint16_t address_page,uint32_t byte_cnt)
{


    /*sned the program load command,write data to cache*/
    bsp_spi_nandflash_program_load(buffer, address_page, byte_cnt);
    /*sned the program excute command*/
    bsp_spi_nandflash_program_execute(page_No);
    /* Check program result */
    while(bsp_spi_nandflash_get_status_flag(OIP)==SPI_NAND_BUSY);

    
#ifdef WRITE_PAGE_VERIFY_EN
     spi_nandflash_read_data (tem_buffer,page_No, address_page, byte_cnt);
    if (memcmp(tem_buffer, buffer,  byte_cnt) != 0){
        return SUCCESS;
    }
#endif
    return 1;

}

NOR FLASH按page读取函数spi_nandflash_read_data，输入读取数据指针、page号、page内地址偏移、读取长度；该函数流程是：

读page到缓冲区，实现流程：向NOR FLASH发送写缓冲区指令0x13->送要读取的page号

等待OIP标志（NAND读取page到缓冲区完成）

从缓冲区读取数据，实现流程：发送读cache命令0x03->发送要读取的page地址偏移->读取所需长度的数据

查询是否有ecc错误

C
/*!
    \brief      send the read page command
    \param[in]  page_No: the serial number of nandflash page
    \param[out] none
    \retval     none
*/
void bsp_spi_nandflash_page_read(uint32_t page_No)
{
    /* select the flash: chip select low */
    bsp_spi_nand_cs_low();
    /* send "PAGE READ" command */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,SPI_NAND_PAGE_READ);
    /* send the serial number of page */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(page_No>>16)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(page_No>>8)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,page_No&0xFF);
    /* deselect the flash: chip select high */
    bsp_spi_nand_cs_high();
}

/*!
    \brief      send the read cache command
    \param[in]  buffer: a pointer to the array
    \param[in]  address_in_page: the address in nandflash page
    \param[in]  byte_cnt: the number of data
    \param[out] none
    \retval     none
*/
void bsp_spi_nandflash_read_cache(uint8_t *buffer,uint16_t address_in_page,uint32_t byte_cnt)
{
    uint32_t i=0;

    /* select the flash: chip select low */
    bsp_spi_nand_cs_low();
#ifdef SPI_NANDFLASH
    /* send "PAGE READ" command */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,SPI_NAND_READ_CACHE);
    //driver_spi_master_transmit_receive_byte(&BOARD_SPI,DUMMY_BYTE);//Q4UC ++ Q5 --
    /* send the address of page */
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,(address_in_page>>8)&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,address_in_page&0xFF);
    driver_spi_master_transmit_receive_byte(&BOARD_SPI,DUMMY_BYTE);//Q4UC -- Q5 ++
    
#endif


    
    for(i=0;i<byte_cnt;i++){
        *buffer++=driver_spi_master_transmit_receive_byte(&BOARD_SPI,DUMMY_BYTE);
    }
    
    /* deselect the flash: chip select high */
    bsp_spi_nand_cs_high();
    qspi_disable(BOARD_SPI.spi_x);
}

/*!
    \brief      read the data from nandflash
    \param[in]  *buffer:the data of array
    \param[in]  page_No: the serial number of nandflash page
    \param[in]  address_in_page: the address in nandflash page
    \param[in]  byte_cnt:the number of data
    \param[out] none
    \retval     SPI_NAND_FAIL,SPI_NAND_SUCCESS 
*/
uint8_t spi_nandflash_read_data(uint8_t *buffer,uint32_t page_No,uint32_t address_in_page,uint32_t byte_cnt)
{
    uint8_t result = SPI_NAND_SUCCESS;
    uint8_t status = 0;
    uint8_t retrycnt = 0;

    /* the capacity of page must be equal or greater than the taotal of address_in_page and byte_cnt */
    if((address_in_page+byte_cnt)>SPI_NAND_PAGE_TOTAL_SIZE){
        return SPI_NAND_FAIL;
    }
ReadRetry:
    /* send the read page command */
    bsp_spi_nandflash_page_read(page_No);
    /* wait for NANDFLASH is ready */
    while(bsp_spi_nandflash_get_status_flag(OIP)==SPI_NAND_BUSY);
    /* read data from cache */
    bsp_spi_nandflash_read_cache(buffer, address_in_page, byte_cnt);
    
    bsp_spi_nandflash_get_feature( STATUS, &status );
    if(( (status & ECCS0) == 0 )&&( (status & ECCS1) == ECCS1 )){    //UECC
        if(retrycnt < 3)
        {
            retrycnt++;

            printf("\rReadretry:%x %x\n",retrycnt,page_No); 
      
            goto ReadRetry;
        }
        else
        {
            printf("\rRead Fail %x\n",page_No);
        }      
    }             
    return result;
}

20.4.3 main函数实现

main函数中实现了擦除一个block，并对该block中的page进行写入操作，然后读取后进行数据对比校验的功能。

C
/*!
* 说明     main函数
* 输入     无
* 输出     无
* 返回值   无
*/
int main(void)
{
   
    //延时、共用驱动部分初始化 
    driver_init();
          
    //初始化LED组和默认状态
    bsp_led_group_init();
    bsp_led_on(&LED0);
    bsp_led_off(&LED1);     

    //初始化UART打印
    bsp_uart_init(&BOARD_UART);

    //初始化SPI    
    bsp_spi_init(&BOARD_SPI);
    
    //初始化SPI NAND         
    bsp_spi_nand_init();
  
    printf("\n\rSPI NAND:GD5F1G configured...\n\r");

    //读取flash id    
        flash_id=bsp_spi_nandflash_read_id();
    printf("\n\rThe NAND_ID:0x%X\n\r",flash_id);  

    //比对flash id是否一致
    if(NAND_ID != flash_id)
        {
        printf("\n\r\n\rWrite to tx_buffer:\n\r\n\r");

        //准备数据
        for(uint16_t i = 0; i < BUFFER_SIZE; i ++){
            tx_buffer[i] = i;
            printf("0x%02X ",tx_buffer[i]);

            if(15 == i%16)
                printf("\n\r");
        }

        printf("\n\r\n\rRead from rx_buffer:\n\r");

        //擦除要写入的block        
        bsp_nandflash_block_erase(0);
        //写入数据         
        bsp_nandflash_page_program((uint8_t*)tx_buffer,0,0,0);

        //回读写入数据
        bsp_nandflash_page_read(rx_buffer,0,0);        

        /* printf rx_buffer value */
        for(uint16_t i = 0; i <= 255; i ++){
            printf("0x%02X ", rx_buffer[i]);
            if(15 == i%16)
                printf("\n\r");
        }

        //比较回读和写入数据        
        if(ERROR == memory_compare(tx_buffer,rx_buffer,BUFFER_SIZE)){
            printf("Err:Data Read and Write aren't Matching.\n\r");
            /* spi flash read id fail */
            printf("\n\rSPI nand: Read ID Fail!\n\r");
            
            //写入错误            
            /* turn off all leds */
            bsp_led_on(&LED0);
            /* turn off all leds */
            bsp_led_on(&LED1);           
            while(1);
        }else{
            printf("\n\rSPI-GD5F1G Test Passed!\n\r");
        }
    }else{ //ID读取错误
        /* spi flash read id fail */
        printf("\n\rSPI Nand:Read ID Fail!\n\r");
        /* turn off all leds */
        bsp_led_on(&LED0);
        /* turn off all leds */
        bsp_led_on(&LED1);           
        while(1);
    }

    while(1){
        /* turn off all leds */
        bsp_led_toggle(&LED0);
        /* turn off all leds */
        bsp_led_toggle(&LED1);        
        delay_ms(200);
    }
}

20.5 实验结果

nand读取到正确ID后开始擦写读流程，如果ID读取错误或者数据比对不通过点亮LED0，熄灭LED1，如果比对通过则交替闪烁LED0和LED1，通过USB转串口可以看到打印结果。