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如何使用mcu 内置 flash 实现fatfs

news 来源：原创 2024/9/20 1:12:31

一、环境与目的

AT32F403AVGT7，FLASH从0x80e0000到最后，共128K。扇区大小为512。

注意：Flash 的扇区大小为2KB。

fatfs 80286 /* Revision ID */

目标在于利用单片机1MBflash后面的一小部分，以方便应用程序存储系统参数。

1）diskio.c里ioctl下：

case DEV_SYS :switch(cmd){case CTRL_SYNC:result = RES_OK;break;case GET_SECTOR_SIZE:*(DWORD*)buff = 512;result = RES_OK;break;case GET_SECTOR_COUNT://*(DWORD*)buff = ABLINKFLASH_SIZE/2048;*(DWORD*)buff = 256;result = RES_OK;break;case GET_BLOCK_SIZE:*(DWORD*)buff = 1;result = RES_OK;break;default:result = RES_PARERR;break;}

2) 读写函数：

void flash_write_byte_nocheck(uint32_t write_addr, uint8_t *p_buffer, uint32_t num_write){             uint32_t i;uint32_t writeNum   = num_write*512;uint32_t headAddr, tailAddr;write_addr = write_addr*512+ABLINKFLASH_START_ADDR;while(writeNum){headAddr        = write_addr - write_addr%2048;//(write_addr>>11)<<11;tailAddr        = headAddr+2048;n_ReadSector(headAddr);for(i=write_addr; i<tailAddr; i++){flushSectorBuff[i-headAddr]     = p_buffer[i-write_addr];writeNum--;if(0==writeNum){break;}}n_WriteSector(headAddr);}} void flash_read_byte(uint32_t read_addr, uint8_t *p_buffer, uint32_t num_read){ uint32_t i;uint32_t readCount  = num_read*512;uint32_t sectora    = read_addr<<9;uint8_t* pu8T_Temp;for(i = 0; i < readCount; i++){pu8T_Temp         = (uint8_t*)(sectora+ABLINKFLASH_START_ADDR+i);p_buffer[i]       = *pu8T_Temp; }  
}

二、解析如下：

三、验证代码如下：

 res = f_mkfs("0:", 0, buffer, 1024);if(FR_OK==res){aBlink.uart_usb->send("f_mkfs ok...\r\n", 14);}else{aBlink.uart_usb->send("f_mkfs error...\r\n", 17);}res = f_mount(&fatfs, "0:", 1);if(FR_OK==res){aBlink.uart_usb->send("fatfs mount success.\r\n", 22);res = f_open(&fil, "0:123456.txt", FA_OPEN_ALWAYS);if(FR_OK==res){aBlink.uart_usb->send("fatfs open success...\r\n", 23);res = f_close(&fil);if(FR_OK==res){aBlink.uart_usb->send("fatfs close success...\r\n", 24);}else{aBlink.uart_usb->send("fatfs close error...\r\n", 24);}}else{aBlink.uart_usb->send("fatfs open error...\r\n", 23);}}else{aBlink.uart_usb->send("fatfs mount error.\r\n", 22);}