Class Specific Notifications for CDC ECM

[sujan.nag]

Hello All,

I am developing a device, similar to any COTS Ethernet over USB devices. It has a USB port working as a device to the Host PC, and a standard Ethernet port. For development I am using AM3354 from TI, and using Starterware v2.0 for development.

On the process of developing a USB CDC ECM Device side driver, I went through the ECM120.pdf spec. I am not clear about the notifications which are supposed to be sent by the device, NETWORK_CONNECTION and CONNECTION_SPEED_CHANGE.

My query is, under what circumstances does a device need to send this notification to the Host?

Thanks and Regards
Sujan Nag

[Jan Axelson]

The device sends the notifications when the host requests them.

The ECM spec says that the device sends notifications using the management element, which means they use control transfers.

6.3 in the ECM spec lists the values the host will use to request these notifications, and the values the device should use in responding.