## MMPM/2 Device Driver Reference

[prev][next][parent][TOC]

### VSD Architecture

The VSD layer is a device-independent physical device driver-like layer that resides in Ring 3. It passes information between the media control interface subsystem and multimedia devices. [Artwork not shown] A VSD has the following characteristics:

Does not deal with media control interface notifications.
Usually uses a single standard time format (milliseconds).
Usually does not have to deal with file management.