CRC error in all USB SOF packets

[petereckstrand9]

Posted on July 08, 2015 at 16:04

Hi,

I'm running a stm32f427 on a custom board as Host, HS core, FS mode. 

When a device is attached I get an interrupt when the device is detected and the host starts sending SOF's. But the last bits in the SOF packet is at a strange voltage level. They are at 1.5 V, a half one!

Look at this scope image:

https://drive.google.com/open?id=0B3wMeRPstoowY3VFN0hWYk8zVllzNk1UMzA3V1hpcFdNZjk4

Anyone have seen this before or can explain it? 

The device does not reply on requests as it detects a CRC error.

#sof #stm32 #usb