/**
@page EEPROM_Emulation application to show an eeprom emulation
@verbatim
******************* (C) COPYRIGHT 2016 STMicroelectronics ********************
* @file EEPROM_Emulation/readme.txt
* @author MCD Application Team
* @brief Description of the EEPROM_Emulation application.
******************************************************************************
*
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
@endverbatim
@par Application Description
This application describes the software solution for substituting standalone EEPROM
by emulating the EEPROM mechanism using the on-chip Flash of STM32F7xx devices.
Please refer to AN3969 for further details regarding this application.
The application requires two Flash memory sectors of identical size allocated to non-volatile data:
one that is initially erased, and offers byte-by-byte programmability; the other that is ready
to take over when the former sector needs to be garbage-collected. A header field that occupies
the first half word (16-bit) of each sector indicates the sector status. Each of these sectors is
considered as a page.
The sectors used are Sector 2 and Sector 3 with a size of 32KB each one.
STM327x6G-EVAL's LEDs can be used to monitor the application status:
- LED1 is toggle when the example runs successfully.
- LED3 is toggle in case of error.
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
@note The application need to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.
@par Keywords
EEPROM, Emulation, Flash, Program, Erase, Sectors, OPCODE
@Note<74>If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
<20><><A0><A0><A0>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
<0A><><A0><A0><A0><A0>The address and the size of cacheable buffers (shared between CPU and other masters) must be properly updated to be aligned to cache line size (32 bytes).
@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
<0A><><A0><A0><A0> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
<0A><><A0><A0><A0><A0>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
<0A><><A0><A0><A0><A0>Even though the user must manage the cache coherence for read accesses.
<0A><><A0><A0><A0><A0>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
<0A><><A0><A0><A0><A0>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
@par Directory contents
- EEPROM_Emulation/Inc/stm32f7xx_hal_conf.h HAL Configuration file
- EEPROM_Emulation/Inc/main.h Header for main.c module
- EEPROM_Emulation/Inc/eeprom.h Header for eeprom.c module
- EEPROM_Emulation/Inc/stm32f7xx_it.h Header for stm32f7xx_it.c
- EEPROM_Emulation/Src/main.c Main program
- EEPROM_Emulation/Src/eeprom.c EEPROM program
- EEPROM_Emulation/Src/stm32f7xx_it.c Interrupt handlers
- EEPROM_Emulation/Src/system_stm32f7xx.c STM32F7xx system clock configuration file
@par Hardware and Software environment
- This example runs on STM32F756xx/STM32F746xx devices.
- This example has been tested with STM327x6G-EVAL board revB and can be
easily tailored to any other supported device and development board.
Table 1. EEPROM application implementation on STM327x6G-EVAL RevB
/*** Platform ***|************* Implementation **************************|***** Configuration *****\
****************************************************************************************************
| Firmware | The EEPROM program is located at 0x08000000. The Flash| |
| | routines (program/erase) are executed from the Flash | |
| | memory. | |
| | The size of this program is about 6 Kbytes and | |
| | programmed on: | Sector 0 |
| | ------------------------------------------------------|-------------------------|
| | | |
| | The flash zone used for the EEPROM emulation is | 64KB |
| | located at 0x08010000 | (Sector 2- Sector3) |
| | | |
\**************************************************************************************************/
Following picture illustrates the situation in program memory:
Top Flash Memory address /-------------------------------------------\ 0x080FFFFF
| |
| |
| |
| |
| |
| Sector 4 - Sector 7 |
| |
|-------------------------------------------| 0x08020000
Sector 3 (32KB) | |
| |
| Flash used for EEPROM emulation mechanism | 0x08018000
Sector 2 (32KB) | |
| |
|-------------------------------------------| 0x08010000
Sector 1 (32KB) | |
| |
|-------------------------------------------| 0x08008000
| |
Sector 0 (32KB) | flash used for implement the EEPROM |
| emulation mechanism(6KB) |
\-------------------------------------------/ 0x08000000
@par How to use it ?
In order to make the program work, you must do the following :
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the example
*/
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