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Why am I getting a conflict using 32 bit SRMA in FMC with using RGB888

RLarr.1
Associate II

I am upgrading an STM32F429IIT6 project that uses an external SRAM and an RGB888 LCD. The product currently works as it was set up with emWin and an older version of STMCubeMX but now I need to update to use TouchGFX. However STM32CubeIDE/STM32MX pin mapping gives a conflict when attempting to set the SRAM as 32 bits wide and the LTDC to RGB888.

I have stripped out most everything else with no change. I am not using an OS. What might I be missing?

Thanks,

Raymond

5 REPLIES 5
MM..1
Chief II

When you mean red colored options , i mean this is only reported LCD FMC fuctions not available. FMC can connect to LCD interfaces, but you use it for SRAM.

Look at the pin selections for the working model. Probably giving up 1 Red pin to accommodated 32-bit SDRAM pins/expectations.

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RLarr.1
Associate II

Thank you Tesla. I missed the SDRAM chip has DQM1 and DQM2 tied together in the schematic freeing PI4 to be used for the LTDC_B4 feature of the LCD.

I am guessing now my solution would be to set the LCD and the SDRAM to 16 bits to create source inSTM32CubeMX. Then generate source code with no LCD and 32 bit SDRAM. Next combining the parameters of the 32 bit SDRAM into my first code with LCD.

If there is a better solution I would appreciate hearing it. My suggestion above seems very manual and would have to be duplicated any time STM32CubeMX was ran.

I'm not a strong advocate of code generation tools and then hitting the button over and over.​ I suppose if the post generation fix up became tedious I'd script a diff/merge operation..

N​ot sure what would be the simplest way to make CubeMX happy, perhaps find the least number of conflicting pins and remove those. Or merge in the full working SDRAM instance as you say.

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You jump from SRAM to SDRAM and in subject SRMA maybe you need choice one.