STM8S——Flash program memory and data EEPROM

1、简介

　　STM8S内部的FLASH程序存储器和数据EEPROM是由一组通用寄存器来控制的；所以我们可以通过这些通用寄存器来编程或擦除存储器的内容、设置写保护、或者配置特定的低功耗模式。我们也可以自己对器件的 option byte 进行编程。在这里我们只简单的讲解如何对STM8S内部的数据存储区域（data memory）进行写操作、读操作、擦除操作。

2、存储架构图

STM8S内部存储包括：FLASH程序存储器（FLASH program memory）和数据EEPROM（DATA EEPROM）；

（1）数据EEPROM又包括：

数据存储区域（DATA MEMORY）：指定从地址0x00 4000开始，其中包括 [1 block] 的option byte，数据存储区域用于存储应用数据；

（2）FLASH程序存储器又包括：

用户启动区域（USER BOOT CODE）：指定从地址0x00 8000开始，其中包括UBC option bytes和 [128 byte] 的中断矢量（interrupt vectors）；

程序存储区域（MAIN PROGRAM）：用于存储应用程序代码；

1 /* Includes ------------------------------------------------------------------*/
2 #include "stm8s.h"
3
4 /* Private typedef -----------------------------------------------------------*/
5 typedef enum { FAILED = 0, PASSED = !FAILED} TestStatus;
6
7 /* Private variables ---------------------------------------------------------*/
8 __IO TestStatus OperationStatus;
9
10
11 /**
12   * @brief How to Read / Write / Erase one Byte on FLASH memory.
13   * @par   Examples description
14   *        - Read one byte at address 0x40A5
15   *        - Write its complement value at address + 1
16   *        - Check programed value
17   *        - Erase 2 byte (address 40A5 & 40A6)
18   *        - Check the 2 bytes value is 0x00.
19   * @param  None
20   * @retval None
21   */
22 void main(void)
23 {
24
25     uint8_t val = 0x00, val_comp = 0x00;
26     uint32_t add = 0x00;
27
28     /* Define FLASH programming time */
29         //Standard programming time fixed at 1/2 tprog
30     FLASH_SetProgrammingTime(FLASH_PROGRAMTIME_STANDARD);
31
32     /* Unlock Data memory */
33         //compare to two hardware key value: 0x56 and 0xAE
34     FLASH_Unlock(FLASH_MEMTYPE_DATA);
35
36     /* Read a byte at a specified address */
37     add = 0x40A5;
38         //read one byte from the address
39     val = FLASH_ReadByte(add);
40
41     /* Program complement value (of previous read byte) at previous address + 1 */
42     val_comp = (uint8_t)(~val);
43         //modify one byte at the address
44     FLASH_ProgramByte((add + 1), val_comp);
45
46     /* Check program action */
47     val = FLASH_ReadByte((add + 1));
48     if (val != val_comp)
49     {
50         /* Error */
51         OperationStatus = FAILED;
52         /* OperationStatus = PASSED, if the data written/read to/from DATA EEPROM memory is correct */
53         /* OperationStatus = FAILED, if the data written/read to/from DATA EEPROM memory is corrupted */
54         while (1)
55         {
56         }
57     }
58
59     /* Erase byte at a specified address & address + 1 */
60         //erase one byte at the address
61     FLASH_EraseByte(add);
62     FLASH_EraseByte((add + 1));
63     /* Erase action */
64     val = FLASH_ReadByte(add);
65     val_comp = FLASH_ReadByte((add + 1));
66     if ((val != 0x00) & (val_comp != 0x00))
67     {
68         /* Error */
69         OperationStatus = FAILED;
70         /* OperationStatus = PASSED, if the data written/read to/from DATA EEPROM memory is correct */
71         /* OperationStatus = FAILED, if the data written/read to/from DATA EEPROM memory is corrupted */
72         while (1)
73         {
74         }
75     }
76
77     /* Pass */
78     OperationStatus = PASSED;
79     /* OperationStatus = PASSED, if the data written/read to/from DATA EEPROM memory is correct */
80     /* OperationStatus = FAILED, if the data written/read to/from DATA EEPROM memory is corrupted */
81     while (1)
82     {
83     }
84 }

FLASH