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STM32H7 Simultaneous 16‑bit SDRAM and 16‑bit PSSI Support

Bora
Associate

Hello,

I am designing a system that must continuously capture data from a 30 MSPS, 16‑bit parallel ADC into a 16‑bit SDRAM using a circular buffer.

The DCMI peripheral is not suitable for this parallel ADC interface because no VSYNC or HSYNC signals are available—only the ADC clock is provided. Consequently, the most appropriate peripheral appears to be the PSSI (Parallel Synchronous Slave Interface).

I would prefer to use an STM32H7 series MCU running at 550 MHz. To my knowledge, the models that integrate both an SDRAM‑capable FMC and a PSSI peripheral are the STM32H723, STM32H725, STM32H730, and STM32H735.

A standard 16‑bit SDRAM with 13 address lines and 4 banks requires 39 control signals when including FMC_NBL0 and FMC_NBL1 for the byte enables. The 16‑bit ADC supplies 17 signals (16 data lines plus a clock). The total pin count is therefore 56.

I have attempted to configure all of the above‑mentioned MCUs using STM32CubeMX, but I have never been able to enable both a 16‑bit SDRAM and a 16‑bit PSSI simultaneously—they consistently conflict on pin assignments.

Could you please confirm which STM32 MCU, if any, supports simultaneous operation of a 16‑bit SDRAM and a 16‑bit PSSI? If no single device can accommodate this combination, I would be grateful for any recommended workaround.

Thank you very much.

Best regards,
Bora

1 ACCEPTED SOLUTION

Accepted Solutions
mƎALLEm
ST Employee

Hello @Bora and welcome to the ST community,

I did the exercise with STM32H5F4IJ on CubeMx and found SDRAM 16-bit and PSSI can be used in parallel.

I've attached the ioc file. Please check.

mALLEm_0-1780568147203.pngmALLEm_1-1780568159066.png

I see this warning but I don't think there is a real conflict.

mALLEm_2-1780568349066.png

Please check.

 

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.

View solution in original post

4 REPLIES 4
mƎALLEm
ST Employee

Hello @Bora and welcome to the ST community,

I did the exercise with STM32H5F4IJ on CubeMx and found SDRAM 16-bit and PSSI can be used in parallel.

I've attached the ioc file. Please check.

mALLEm_0-1780568147203.pngmALLEm_1-1780568159066.png

I see this warning but I don't think there is a real conflict.

mALLEm_2-1780568349066.png

Please check.

 

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.
Bora
Associate

Thank you very much for your prompt assistance. Your suggested MCU operates at 250 MHz. Could you please suggest a significantly faster alternative(s)?

Bora
Associate

OK I also find a solution by choosing a BGA package for STM32H723 (550MHz). There is no solution for LQFP package although both have 144 pins/balls.

Thanks again...

Bora
Associate

To avoid any misunderstanding, I should clarify that the issue was related to the CubeMX version.

My previous version were CubeMX‑6.14.1 or CubeMX‑6.15.0 (I am not entirely sure which, as I have uninstalled it and not noted). However, with CubeMX‑6.17.0, no problem occurs for either the BGA or the FQFP package.