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Associate
August 26, 2025
Question

m95m01-A125 not working with 10MHz clock

  • August 26, 2025
  • 3 replies
  • 962 views

The M95M01-DWMN3TP/K (NVM) is connected to a custom MPC5775B board. It works with a 5 MHz clock. According to the datasheet, it should support frequencies above 8 MHz, but it does not work with an 8–10 MHz clock or higher.

3 replies

Peter BENSCH
Technical Moderator
August 26, 2025

Welcome @azezurrehman, to the community!

You didn't ask a question, but I'm guessing you want to know what you need to do to get it to work up to the 16MHz mentioned in the data sheet?

Well, SPI is based on single-ended transfers, so the usable clock frequency depends on the environment, e.g. the layout. If you want a statement on this, you should therefore provide information on the layout.

Regards
/Peter

Associate
August 26, 2025

dear @Peter BENSCH 

Thank you for your response.

Could you please clarify what exact layout guidelines or connection considerations we should follow to ensure reliable communication between 8 MHz and 16 MHz, as mentioned in the datasheet?

If there are specific recommendations regarding trace length, termination, grounding, or decoupling for SPI lines at these speeds, that would be very helpful.

Appreciate your support.

Best regards,
Azezur Rehman

Peter BENSCH
Technical Moderator
August 27, 2025

Well, the general recommendations for SPI apply, which can be found in abundance on the Internet using your preferred search engine, e.g. here or there.

In addition, the parameters of the SPI pins of the MCUs used also play an important role, so you should contact its manufacturer about this.

Good luck!
/Peter

Andrew Neil
Super User
September 1, 2025

@azezurrehman wrote:

 a custom MPC5775B board. .


For a custom board, you need to provide details: schematics and, as @Peter BENSCH said, layout.

Good, clear photos may also help

See: How to write your question to maximize your chances to find a solution

 

Have you used an oscilloscope to check that the signals are good & clean - especially at the higher frequencies?

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
Peter BENSCH
Technical Moderator
September 26, 2025

@azezurrehman  @azezur_rehman 

The schematics were a first step, but do you have any further information that would help us to assist you?

Did you examine the signals with a suitable oscilloscope, as suggested by @Andrew Neil?

Regards
/Peter