{"id":2182,"date":"2023-12-13T04:26:12","date_gmt":"2023-12-13T04:26:12","guid":{"rendered":"https:\/\/blog.embeddedexpert.io\/?p=2182"},"modified":"2023-12-13T04:26:51","modified_gmt":"2023-12-13T04:26:51","slug":"w25qxx-in-spi-with-external-loader-part-2-flash-source-code","status":"publish","type":"post","link":"https:\/\/blog.embeddedexpert.io\/?p=2182","title":{"rendered":"W25QXX in SPI with External Loader Part 2: Flash Source Code"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

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In part 1, we setup the environment and created the header file for the required functions and symbolic to be hold.<\/p>\n\n\n\n

In the second part of the external loader, we shall develop the source file for W25QXX.<\/p>\n\n\n\n

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9. W25QXX Source file:<\/h2>\n\n\n\n

We start off by creating new source file with name of W25QXX.c.<\/p>\n\n\n\n

Within the source file, include the following:<\/p>\n\n\n\n

#include "W25QXX.h"\n\n#include "SPI1.h"\n\n#include "delay.h"<\/pre><\/div>\n\n\n\n
Then declare the number of blocks (In W25Q32 is 64 blocks):<\/p>\n\n\n\n
#define NumberOfBlocks 64  \/\/ number of total blocks for 32Mb flash<\/pre><\/div>\n\n\n\n
Now, we declare a function that will read the status register and check if the write\/eras is still in progress:<\/p>\n\n\n\n
static void W25Q_Waitforwrite()\n{\n\tuint8_t tData = W25Q_READ_SR1;\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(&tData, 1);\n\tdo\n\t{\n\t\tSPI1_Receive(&tData, 1);  \/\/keep reading status register\n\t} while (tData & 0x01);  \/\/ until the bit to reset\n\tW25QXX_CS_HIGH();\n}\n<\/pre><\/div>\n\n\n\n
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For write enable\/disable functions:<\/p>\n\n\n\n
static void write_enable (void)\n{\n\tuint8_t tData = W25Q_WRITE_ENABLE;  \/\/ enable write\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(&tData, 1);\n\tW25QXX_CS_HIGH();\n\tdelay(5);  \/\/ 5ms delay\n}\n\nstatic void write_disable(void)\n{\n\tuint8_t tData = W25Q_WRITE_ENABLE;  \/\/ disable write\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(&tData, 1);\n\tW25QXX_CS_HIGH();\n\tdelay(5);  \/\/ 5ms delay\n}\n<\/pre><\/div>\n\n\n\n
For more details about this, please refer to this guide.<\/a><\/p>\n\n\n\n
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Bytes to write and modify functions:<\/p>\n\n\n\n
static uint32_t bytestowrite (uint32_t size, uint16_t offset)\n{\n\tif ((size+offset)<256) return size;\n\telse return 256-offset;\n}\n\nstatic uint32_t bytestomodify (uint32_t size, uint16_t offset)\n{\n\tif ((size+offset)<4096) return size;\n\telse return 4096-offset;\n}\n<\/pre><\/div>\n\n\n\n
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Flash reset and get the ID:<\/p>\n\n\n\n
void W25Q_Reset (void)\n{\n\tuint8_t tData[2];\n\ttData[0] = W25Q_ENABLE_RST;  \/\/ enable Reset\n\ttData[1] = W25Q_RESET;  \/\/ Reset\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(tData, 2);\n\tW25QXX_CS_HIGH();\n\tdelay(100);\n}\n\nuint32_t W25Q_ReadID (void)\n{\n\tuint8_t tData = 0x9F;  \/\/ Read JEDEC ID\n\tuint8_t rData[3];\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(&tData, 1);\n\tSPI1_Receive(rData, 3);\n\tW25QXX_CS_HIGH();\n\treturn ((rData[0]<<16)|(rData[1]<<8)|rData[2]);\n}\n<\/pre><\/div>\n\n\n\n
For more details about these two functions, please refer to this guide<\/a>.<\/p>\n\n\n\n
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Chip erase functions:<\/p>\n\n\n\n
void W25Q_Chip_Erase (void)\n{\n\tuint8_t tData = W25Q_CHIP_ERASE;\n\n\twrite_enable();\n\n\tW25QXX_CS_LOW();\n\tSPI1_Transmit(&tData, 1);\n\tW25QXX_CS_HIGH();\n\n\tW25Q_Waitforwrite();\n\n\twrite_disable();\n}<\/pre><\/div>\n\n\n\n
The following steps are required:<\/p>\n\n\n\n