F746 custom board

[MReus.2]

Hello,

I made a custom f746 board like it is done on the discovery board. I have only implemented SDRAM and QuadSPIFlash. I can program the mcu without any problems. The display flickers heavily  https://youtube.com/shorts/pYuCkyMqsgM?si=iGS41lJvxs_CgsnH

I am trying to get an inage on the display without SDRAM to check if the basic setup with mcu and display works. Any other tips on what this could be?

Thanks

Martin

[KnarfB]

What driver code are you using? HAL? BSP?

You may start with some RAM tests to verify the SDRAM independently of the display interface, like https://developer.arm.com/documentation/100026/0103/PMC-R52/Production-test-March-algorithm/March-algorithms

On the other side, the display interface allows to set some constant background color for output independently of SDRAM content.

hth

KnarfB

[MReus.2]

Thanks for your reply!

The project was generated with touchGFX and ran on the F746 Discovery board. I redrew the MCU, SDRAM and QUAD SPI Flash so it should work the same. I had no problems on the Discovery board.

There is no problem if only one or two screen with simple background, a switch and a couple of Text Areas are added. This is shown fine. But for more komplex tasks it stops working properly. 

To me it seems like there is an issue with external memory. Is there some kind of example for that March algorithm?

Any hints are highly appreciated!

[KnarfB · Accepted solution]

For STM32, I don't know, but they all are alike: https://github.com/MicrochipTech/classb_mcu32/blob/master/software/Microchip/Class%20B/SSL_MarchCRamTest.c

SDRAM can have more dynamic faults not strictly covered by the above. So you may add some own RAM stress tests.

KnarfB