STM32F7_MEMORY_MAPPED_SDRAM

This example is based on the following configuration:

• STM32F746G-DISCO
• Ac6 SystemWorkbench
• STM32CubeMX (used to generate the project).

The project demonstrates how to use a memory-mapped SDRAM through the Flexible Memory Controller.

And supports the following features:

Feature	Functions
Base memory helpers	sdram_ex_memset/sdram_ex_memcpy/sdram_ex_memcmp/sdram_ex_get_sp
MPU helpers	sdram_ex_mpu_config_add_region/sdram_ex_mpu_config
A simplistic implementation of a memory heap	sdram_ex_malloc/sdram_ex_free/sdram_ex_is_in_heap
A section to map code data directly into the SDRAM	__attribute__((section (".sdram_data")))

Build

You can build the project with Ac6 SystemWorkbench.

Make sure that HAL_SDRAM_MODULE_ENABLED is defined (normally done with the project configuration).

Note: If you wants to re-generate the project with STM32CubeMX make sure that the FMC is disabled (it is managed by the BSP part).

Run

A tool script is available to read logs from the STM32 ST-Link port.

python serial_log.py --device (device name or path for linux) --bauds 115200

Files

The architecture of the files is not the best, but it has the merit of extracting as much as possible the code of example of the generated code.

Files	Changes
drv/stm32746g_discovery_sdram.[ch]	Copied from STM32Cube/Repository/STM32Cube_FW_F7_V1.7.0/Drivers/BSP/STM32746G-Discovery (Configured for 8 bits data and 12 bits address).
drv/stm327xx_hal_sdram.c + drv/stm327xx_ll_fmc.c	Copied from STM32Cube/Repository/STM32Cube_FW_F7_V1.7.0/Drivers/STM32F7xx_HAL_Driver/Src
drv/stm327xx_hal_sdram.h + drv/stm327xx_ll_fmc.h	Copied from STM32Cube/Repository/STM32Cube_FW_F7_V1.7.0/Drivers/STM32F7xx_HAL_Driver/Inc
app.c	Examples of using memory-mapped SDRAM.
freertos.c	Generated file I added the call of these functions app_init and app_task_loop.
gpio.c	Generated file, no changes.
main.c	Generated file, no changes.
sdram_ex.c	This file contain a set of helpers function and it define the management of the SDRAM heap implementation (malloc+free).
stm32f7xx_hal_msp.c	Generated file, no changes.
stm32f7xx_hal_timebase_TIM.c	Generated file, no changes.
stm32f7xx_it.c	Generated file, no changes.
system_stm32f7xx.c	Generated file, no changes.
usart.c	Generated file, I added the the _write function (to redirect printf on the usart).
STM32F746NGx_FLASH.ld	Generated file, I added the SDRAM memory section and a new section named sdram_data to easily store the data in the SDRAM from the C code.

License (like LGPL)

LGPLv3.txt