Hardware Design Observations for STM32N6570-DK and STM32H747I-DISCO Boards
While working with the STM32N6570-DK and STM32H747I-DISCO boards, I noted a few aspects of their hardware design that could be improved for usability.
1. Shared I²C Bus Between Codec and Touchscreen
The shared I²C bus used by the audio codec and the touchscreen looks elegant from an architectural standpoint, but in practice it creates some challenges.
1a. Access to the codec can take a relatively long time, while the touchscreen is accessed internally by the TouchGFX library.
Although mutex protection can be implemented in the BSP to manage concurrent access, this does not fully resolve the issue — touchscreen responsiveness can still be affected.
1b. On the dual-core STM32H7 board, if one core manages the codec and the other handles the display, additional synchronization is required to ensure safe concurrent access. This can be achieved, but only with extra development effort.
Proposal:
Connect the codec and display to separate I²C buses to improve responsiveness and simplify synchronization.
2. STMod+ Connector and SAI Routing
Currently, no complete SAI interface is routed to the STMod+ connector.
If an external codec or other TDM device needs to be connected, the only option is to use SD and FS from SAI2 and SCK from SAI4 (on STM32H7). While this configuration can work, it introduces a phase shift and is not straightforward.
Proposal:
Route a full SAI interface to the STMod+ connector for easier integration of external audio components.
Conclusion
These considerations are not intended as reasons to redesign the existing boards, but rather as suggestions for future boards.
Thank you for your attention and for providing such capable development platforms.
