USB2.0 HUB with full speed host and low speed device problem

[francisyeung]

Posted on March 10, 2014 at 04:37

Hi, 

I am using stm32f205 to do usb host which is able to use with hub.I am able to do enumeration of hub and device over hub, however, during enumeration of device over hub, it shows lot of error. I use beagle usb 480 to monitor, and it shows invalid PID sequence. Do anyone know what is the reason of it and how to solve it? Below is the log of the errorhttps://drive.google.com/file/d/0B2cNyUj0yazdZE5BVVVzUHdzS00/edit?usp=sharing #usb #stm32

[tsuneo]

Posted on March 10, 2014 at 05:29

> it shows lot of error.

''PRE/ERR packet'' is a PREamble packet, which precedes low-speed downstream packets on full-/low- mixed speed bus. It isn’t any error. The actual errors occur just on the beagle 480 log, on these lines, 0:18.850.763 <Reset>/<Chirp J>/<Tiny J> 0.18.851.339 <Reset>/<Chirp J>/<Tiny J> .. Beagle fails to interpret speed transition of the bus from low- to full-. You may ignore these ''errors'' just on the beagle 480 log, because the host and device continue the transactions without any trouble. Do you see any error, when the beagle is inserted between the hub port and the low-speed device? Tsuneo

[francisyeung]

Posted on March 10, 2014 at 06:45

Hi Chinzei,

Thanks for your reply. There is no error when the beagle is inserted between the hub port and the low-speed device. I am able to use HID keyboard over hub with my usb host. However, it will be quite annoying since these ''errors'' keep being generated when usb host do HID polling, the log run so fast that i am difficult to read the real data. below is the log of the ''errors'':https://drive.google.com/file/d/0B2cNyUj0yazdQV85VFpHVzFXSkk/edit?usp=sharingAnyway, thank you very much.