Class specific requests in USB to Serial converter

Hi all,

Presently I'm working on USB to Serial device converter. For that I need to feed different class specific discriptors' data like Abstract Control Management Functional Discriptor, Call Management Functional Descriptor, Header Functional Descriptor and Union Functional Descriptor in enumeration process.

I've set a value of 0x07 in Abstract Control Management Functional Discriptor's bmCapabillities bitmap field, which indicates that my configuration supports SEND_BREAK, SET_LINE_CODING, GET_LINE_CODING, SET_CONTROL_LINE_STATE, SET_COMM_FEATURE, GET_COMM_FEATURE, CLEAR_COMM_FEATURE and SERIAL_STATE requests.

When I connect realterm/hyperterminal to my virtual com port, I'm getting SET_LINE_CODING, GET_LINE_CODING and SET_CONTROL_LINE_STATE requests except SEND_BREAK, SET_COMM_FEATURE, GET_COMM_FEATURE, CLEAR_COMM_FEATURE and SERIAL_STATE.

So, just want to know that how I'll get these remained class specific requests while data transmission from USB to Serial or Serial to USB?

In USB to Serial converter, there is an interrupt endpoint(notification element) through which I need to pass status notifications to the host. How I can send status notifications to the Interrupt endpoint? Is there any format/sequence to send the notification? How many data I need to send through?

(Note : There isn't any exact information mentioned in USB Communication Device Class spec for data format/sequence and no. of bytes which I need to send through notification element/interrupt endpoint)

Thanks in advance.

Harshil