PORTS Forum

Ports and Interfaces => USB => Topic started by: Selva on April 10, 2014, 12:49:46 am

Title: Vinculum attach and de-attach problem for cdc device
Post by: Selva on April 10, 2014, 12:49:46 am
I am using Vinculum 32 pin IC for my application  . I am using 5 cdc device which differs only in PID .
I have connected this 5 cdc device & vinculum through hub .
I have taken  CDC Modem sample code and working on it ,
we are facing few problem In attaching & de-attaching the CDC device . while switching from one device
to another ,  Its working properly with that  Vinculum reset function ( vos_reset_vnc2 ) . but we are
trying to do  without reset function .

I want to do proper attach and detach between usb host  & cdc device while switching .
kindly help me to solve this issue .
Title: Re: Vinculum attach and de-attach problem for cdc device
Post by: Jan Axelson on April 10, 2014, 09:26:29 am
I don't have any specific recommendations, but a protocol analyzer will show what is happening on the bus and might offer a clue. Otherwise use whatever debugging tools you have to find out how the host is responding when you detach a device and attach another.
Title: Re: Vinculum attach and de-attach problem for cdc device
Post by: Selva on May 09, 2014, 01:24:31 am
thanks for your reply..
I have some doubts ..
Is it necessary to do re-enumeration to switch from one cdc device to other .
or is it enough if we detach a driver & attach with other cdc device .
Title: Re: Vinculum attach and de-attach problem for cdc device
Post by: Jan Axelson on May 09, 2014, 08:41:40 am
Detaching one device and attaching another requires enumerating the new device.