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Martin42
Associate III
March 18, 2024
Solved

Write to Flash only 64Bit

  • March 18, 2024
  • 5 replies
  • 2069 views

Hello,

Can I only write to the flash with 64 bit variables, or also 32/16/8 bit?
I just used this function for this: HAL_FLASH_Program(FLASH_TYPEPROGRAM_DOUBLEWORD, activepageaddress + u32_Offset, u64_Data)
I have an STM32L432 uC.

I already found this example: https://github.com/STMicroelectronics/STM32CubeL4/blob/master/Projects/NUCLEO-L4P5ZG/Examples/FLASH/FLASH_FastProgram/Src/main.c

Many thanks in advance.

This topic has been closed for replies.
Best answer by STTwo-32

Hello @Martin42 

Flash programming is only by 64-bits at a time. On other series it can be 32-bits.

STTwo32_0-1710763327109.png

For more details refer to this post.

Best Reagrds.

STTwo-32

5 replies

STTwo-32
STTwo-32Best answer
ST Technical Moderator
March 18, 2024

Hello @Martin42 

Flash programming is only by 64-bits at a time. On other series it can be 32-bits.

STTwo32_0-1710763327109.png

For more details refer to this post.

Best Reagrds.

STTwo-32

To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
    Tesla DeLorean
    Tesla DeLorean
    Guru
    March 18, 2024

    You'd use a structure (packed?) or array to consolidate the smaller variables into a larger / usable block that fits the minimum write width of the FLASH memory. You'd then write as a block.

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      Martin42Author
      Associate III
      March 18, 2024

       

      I would like to write a second firmware via Modbus and delete areas in the flash.
      I send the raw HEX file using a PC tool and then write 64 bits at a time, since the flash only allows access with 64 bits.

      To build the HEX file I use the addition "--gap-fill 0x00 --pad-to 0x08019000" to always get addresses with 32 bytes. This should also ensure that 64 bits are always written.
      e.g. arm-atollic-eabi-objcopy.exe -O ihex --gap-fill 0x00 --pad-to 0x08019000 "${BuildArtifactFileBaseName}.elf" "${BuildArtifactFileBaseName}.hex"

      -> Adds ":04018C00000000006F" the missing values for to fill 64 bit

       

      :1001600059C0000859C0000859C00008000000002C
:1001700059C0000859C0000800000000000000003D
:0C01800059C0000859C0000859C0000810
:04018C00000000006F
:1001900010B5054C237833B9044B13B10448AFF3C1
:1001A00000800123237010BD1C010020000000000E

       

       

      Tesla DeLorean
      Tesla DeLorean
      Guru
      March 18, 2024

      Not sure if there was a question there.

      Either normalize the data on the host. Or as you process it on the target

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      Martin42Author
      Associate III
      March 18, 2024

      No question :)

      I will do it on the target.

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