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));

Diff: f042k6_flash.h

Revision:
0:a71e3b72379a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/f042k6_flash.h	Tue Aug 29 02:36:52 2017 +0000
@@ -0,0 +1,76 @@
+// 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_