Yung-Chieh Lo / F042K6_Flash

To access the internal flash of STM32F042K6.

This library provides a Partition class used to segment the STM32F042K6 internal flash so that the caller can read/write/erase the partition.

Examples

    FlashPartition config(0x7c00, 0x400);

    uint8_t buf[16];
    config.Read(address, buf, sizeof(buf));

    config.EraseAll();
    config.Write(address, buf, sizeof(buf));

f042k6_flash.h

Committer:
yjlou
Date:
2017-09-11
Revision:
1:7a490a05943a
Parent:
0:a71e3b72379a

File content as of revision 1:7a490a05943a:

// STM32F042K6 Flash driver
//
// In theory, this should be working on STM32F0x1/STM32F0x2/STM32F0x8, but only
// tested on STM32F042K6.
//
// Please refer to STM RM0091 document for details.
// http://www.st.com/content/ccc/resource/technical/document/reference_manual/c2/f8/8a/f2/18/e6/43/96/DM00031936.pdf/files/DM00031936.pdf/jcr:content/translations/en.DM00031936.pdf

#ifndef F042K6_FLASH_H_
#define F042K6_FLASH_H_

#include "mbed.h"
#include <stddef.h>
#include <stdint.h>

// Memory address to read flash content
// FLASH_BASE and FLASH_BANK1_END are defined in mbed/TARGET_NUCLEO_F042K6/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F042K6/device/stm32f042x6.h
#define USER_FLASH_AREA_START (FLASH_BASE)
#define USER_FLASH_AREA_SIZE  (FLASH_BANK1_END - FLASH_BASE)  // 32KB for F042K6
static const size_t kFlashPageInBytes = 1024;

#define REG32(x) ((volatile uint32_t*)(x))

// FLASH_R_BASE (0x40022000) is defined in mbed/TARGET_NUCLEO_F042K6/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F042K6/device/stm32f042x6.h
// FIXME: looks like the definition in stm32f042x6.h is wrong.
#undef FLASH_R_BASE
#define FLASH_R_BASE (0x40022000)
#define FLASH_ACR (FLASH_R_BASE + 0x00)  // Flash access control register

#define FLASH_KEYR (FLASH_R_BASE + 0x04)  // Flash key register

#define FLASH_OPTKEYR (FLASH_R_BASE + 0x08)  // Flash option key register

#define FLASH_SR (FLASH_R_BASE + 0x0c)  // Flash status register
#define SR_BSY  (1 << 0)  // Busy

#define FLASH_CR (FLASH_R_BASE + 0x10)  // Flash control register
#define CR_LOCK (1 << 7)  // Lock bit
#define CR_STRT (1 << 6)  // Start for erase
#define CR_PER  (1 << 1)  // Page Erase
#define CR_PG   (1 << 0)  // Program

#define FLASH_AR (FLASH_R_BASE + 0x14)  // Flash address register

#define FLASH_OBR (FLASH_R_BASE + 0x1C)  // Flash Option Byte register

#define FLASH_WRPR (FLASH_R_BASE + 0x20)  // Write prtotection register

class FlashPartition {
  public:
    // Constructor:
    // Args:
    //  start_addr: the starting address of the partition. Starting from 0.
    FlashPartition(uint32_t start_addr, size_t size) :
        start_addr_(start_addr),
        size_(size) {}  // TODO: add assertion to check address and size.
    
    // Read flash content in this partition.
    void Read(uint32_t offset, char* buf, size_t len);

    // Write flash content into this partition.
    // Returns true for success.
    bool Write(uint32_t offset, const char* buf, size_t len);
    
    // Erase whole partition
    // Returns true for success.
    bool EraseAll();
    
  private:
    void UnlockControlRegister();
    
    const uint32_t start_addr_;
    const size_t size_;
};

#endif  // F042K6_FLASH_H_