dimtass / stm32f303-ccmram-test Goto Github PK

Note: This code is from this blog post here.

This project is a template project for evaluating and testing the Core-Coupled Memory (CCM) of the STM32F303CC. This memory is 8KB in size and it's the fastest memory in the chip (faster than SRAM). You can map the functions you need in that area by using a compiler attribute like this.

__attribute__((section(".ccmram"))) void function();

Note: I've used this application note for enabling the CCM RAM feature.

In this project I'm using the LZ4 which is a fast compression library. The code for the lib is located in source/libs/lz4/. I've mapped the LZ4_compress_generic() function in the CCMRAM which is located in source/libs/lz4/src/lz4.c.

Furthermore, in order to support the CCM RAM a modification is needed in the default startup source/libs/cmsis/device/startup_stm32f30x.s file and the linker script source/config/LinkerScripts/STM32F303xC/STM32F303VC_FLASH.ld. In this project the modifications are already done, therefore you can use those files to other projects in order to enable the CCM RAM.

Finally, you also need to provide the path of the toolchain to use in the CMAKE_TOOLCHAIN if it's different from the default one. By default is pointing to /opt/toolchains/gcc-arm-none-eabi-9-2019-q4-major.

Because this repo has dependencies on other submodules, in order to fetch the repo use the following command:

git clone --recursive -j8 https://[email protected]/dimtass/stm32f103-cmake-template.git

There are many flags that you can use for building the firmware. This is the format of the buld command:

USE_OVERCLOCKING=<ON/OFF> USE_BLOCK_SIZE=<N> USE_BLOCK_COUNT=<N> USE_CCM=<ON/OFF> USE_SRAM=<ON/OFF> USE_FLASH=<ON/OFF> ./build.sh

• USE_OVERCLOCKING, ON: enable overclocking at 128MHz, OFF: 72MHz
• USE_BLOCK_SIZE, number of bytes used as the block size. Default: 8, which means 8K
• USE_BLOCK_COUNT, number of blocks used for the compression. Default: 512.
• USE_CCM, ON: move compression function to CCMRAM
• USE_SRAM, ON: move compression function to SRAM
• USE_FLASH, ON: move compression function to FLASH

Notes:

• Only one of the USE_CCM, USE_SRAM, USE_FLASH can be ON.
• The processed size will be USE_BLOCK_SIZE*USE_BLOCK_COUNT
• The default processed size is 4MB
• The USE_BLOCK_SIZE can not be larger than 20KB

These are some examples:

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=OFF USE_FLASH=ON ./build.sh

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=OFF USE_FLASH=ON ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=OFF USE_FLASH=ON ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=OFF USE_FLASH=ON ./build.sh

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=ON USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=ON USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=ON USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=OFF USE_SRAM=ON USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=ON USE_SRAM=OFF USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=OFF USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=ON USE_SRAM=OFF USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=8 USE_BLOCK_COUNT=512 \
USE_CCM=ON USE_SRAM=OFF USE_FLASH=OFF ./build.sh

USE_OVERCLOCKING=ON USE_BLOCK_SIZE=16 USE_BLOCK_COUNT=512 \
USE_CCM=ON USE_SRAM=OFF USE_FLASH=OFF

To build the firmware without using CCM then:

CLEANBUILD=true USE_CCM=OFF ./build.sh

To build the firmware using CCM then:

CLEANBUILD=true USE_CCM=ON ./build.sh

To flash the firmware in Linux you need the texane/stlink tool. Then you can use the flash script like this:

./flash.sh

Otherwise you can build the firmware and then use any programmer you like. The elf, hex and bin firmwares are located in the build folder

./build-stm32/src/stm32f303xc-ccm-test.bin
./build-stm32/src/stm32f303xc-ccm-test.hex
./build-stm32/src/stm32f303xc-ccm-test.elf

• CMSIS version: 4.2.0
• StdPeriph Library version: 1.2.3