Using external RAM with STM32U5G9-HSPI

Carlos_Aperton · ‎2025-11-13

Hi Everyone,

I am working on a project with TouchGFX. I'm working with STM32U5G9ZJT6 and I have an external RAM APS12808L-OBM-BA connected via HSPI (Fclk-hspi 100 MHz) in mapped mode.

The project is working, but the image animation are not working well. To solve it I have decided to increase the HSPI frecuency.

The APS12808L-OBM-BA memory can operate at up to 200MHz. However, when I exceed 118MHz, I can't map the memory. You can see a picture below reading the memory after mapping (you see "?").

I have changed the memory read latency (MR0 and MR4) to increase the Fmax.

I need all of suggestions for this issue.

Thanks in advance all

Andrew Neil · ‎2025-11-13

Welcome to the forum.

Please see How to write your question to maximize your chances to find a solution for best results.

In particular, please give details of your hardware - could there be a hardware issue with speeds >118 MHz ?

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.