AnsweredAssumed Answered

USB Transfer with chained transfer descriptors - slow

Question asked by Larry Harmon on Mar 23, 2018
Latest reply on Apr 2, 2018 by Kan_Li

I using the HSUSB on a K61 MCU in device mode.

I'm using firmware based on the old Freescale USB 4.1.1 stack.

 

I have setup a bulk transfer of 1MByte using several transfer descriptors chained in a list.

The transfer completes correctly.

But I notice a 40 microsecond delay between transfer descriptors. (seen on USB analyzer)

Is this normal?  I expected the USB engine to work much faster than that.

 

Anyone have any experience with this?  Is this behavior documented?

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