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USB CDC HOST SPEED KL26

Question asked by Matteo Davanzo on Nov 13, 2015
Latest reply on Nov 23, 2015 by Mark Butcher

Hi everybody,

 

I'm working with Freescale usb stack 4.1.1.

My setup is the following: one FDRMKL25Z that acts as CDC device and one FDRMKL26Z that acts as CDC host.

My test is very simple. I send 1 Mbyte of data in both direction and i misure the speed of the link.

 

At the moment i can achieve only 47 KByte/s and for my purposes this speed is too low.

 

Working with the CDC device connected to the PC i can achieve up to 300 KByte/s. So my opinion is that something on the usb host stack is not working properly.I see that the host stack spend a lot of time in the _usb_khci_task function and i don't understand why.

My program doesn't do anything else, it just send/receive data.

 

Any ideas?

 

Best regards,

Matteo Davanzo

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