Programming the Microsoft Windows Driver Model

USB Endpoints

If you selected USB Function Driver on the first page, the wizard will present a page that allows you to describe the endpoints of your device, as Figure B-6 shows. This page lists the names of variables in your device extension that will hold pipe handles. The order of names corresponds to the order of endpoint descriptors on your device.

NOTE

This page isn t sufficiently complex to let you describe a device with multiple interfaces or with alternate settings for interfaces.

Figure B-6. Page for defining USB endpoints.

Refer to Figure B-7 for an illustration of the dialog box you can use to describe a single endpoint. The Description Of Endpoint group relates to the description of the endpoint in your device firmware and should be self-explanatory. Within the Resources In The Driver group, complete the fields as follows:

• Name Of Pipe Handle In Device Extension

  Supply the name of a DEVICE_EXTENSION member to hold the pipe handle you ll use for operations on this endpoint.

• Maximum Transfer Per URB

  Specify here the maximum number of bytes you ll transfer in a single URB. In general, this value is much larger than the endpoint maximum.

  Figure B-7. Dialog box for adding and editing a USB endpoint.