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Gabriel T
Senior
Dec 16, 2020 10:44 AM UTC
Solved

Custom HID issue : offset in hid data

Hi,

I am working on Nucleo STM32H743ZI

I am using a 64byte size custom usb hid when I send my data frames i get an offset of 6 zeros as shown here :

0693W000006FwU8QAK.pngAny ideas where it comes from ?

Regards,

Gabriel

This topic has been closed for replies.
Ons KOOLI
Ons KOOLIBest answer
Visitor II
Dec 16, 2020 4:07 PM UTC

Hi GTéta.1,

When working with DMA in H7 products you should pay attention on where you put your code.

By default in the linker file, you can see that the RAM starts from 0x20000000 address and ends in 0x2001FFFF which is the DTCM region.

Unfortunately, the DTCM is not accessible by DMA. Therefore, When working with DMA, you should put your code in an accessible region by DMA (for example AXI SRAM).

Please refer to the RM0433 for more details.

Best Regards,

Ons.

4 replies

Gabriel T
Gabriel TAuthor
Senior
Dec 16, 2020 3:13 PM UTC

Update :

The problem disappear if i disable usb dma :

0693W000006FzgbQAC.png

Gabriel T
Gabriel TAuthor
Senior
Dec 16, 2020 3:58 PM UTC

I would like to use DMA, anyparameter I am missing for the USB DMA ?

Ons KOOLI
Ons KOOLIBest answer
Visitor II
Dec 16, 2020 4:07 PM UTC

Hi GTéta.1,

When working with DMA in H7 products you should pay attention on where you put your code.

By default in the linker file, you can see that the RAM starts from 0x20000000 address and ends in 0x2001FFFF which is the DTCM region.

Unfortunately, the DTCM is not accessible by DMA. Therefore, When working with DMA, you should put your code in an accessible region by DMA (for example AXI SRAM).

Please refer to the RM0433 for more details.

Best Regards,

Ons.

Ons KOOLI
Visitor II
Dec 17, 2020 10:23 AM UTC

Hi GTéta.1,

In case your problem is solved, please mark this question as answered by selecting the best answer.

Best Regards,

Ons.