AnsweredAssumed Answered

USB MSC device low transfer rate - STM32F7

Question asked by chris250 on May 18, 2016
Latest reply on Mar 13, 2017 by mikalajunas.vaidas
Hi All,

I am using the latest STM32 Cube distro with an STM32F7x DISCOVERY board for hardware (class 10 uSD card in the slot) and IAR Kickstart development environment.

The USB MSC Device project (high speed port through ULPI) works/builds well. However... the file transfer rate (writing from PC to the device) is very low (~350kBps).

Debugging the code showed that on line 351 of usbd_conf.c, DMA is disabled for the USB HS port. I enabled DMA at this point (changed the 0 to a 1) but there is still no improvement.

There are a couple of other posts on this subject already (here and here) but no advice available.

Am I missing something obvious? I am expecting too much performance from the hardware?

Thanks in advance.