AnsweredAssumed Answered

USB DMA request fails

Question asked by Dirk Schmitt on Jul 27, 2015
Latest reply on Aug 10, 2015 by alejandrolozano

Hi all,


currently we have problems with usb dma. If I read data with the cpu from the receive buffer of the usb dma, while the usb dma stremas data into it, the received data are corrupted.

My questions are:


What is the priority of the usb dma transfer on the ahb bus?

I started to read the doc of the NIC301 and I saw that there are QoS values which refelcts the priority of the bus masters. How can I check these

Qos values and where can I modify these?


-> Info on 07/29/2015: I found out that the data cache is enable for the RX Buffer. But in the MQX driver code the data ache lines of the

rx buffer are flushed before the dma request is started. It seems to me that the flushing of the data cache line is not sufficient in this case?



Thank you,



Nachricht geändert durch Dirk Schmitt