Lucent Technologies manual USS-720 USB Device Driver, Introduction

Preliminary User Guide, Rev. 2

February 1999

USS-720

USB Device Driver

1 Introduction

This document describes the design and implemen- tation of USS720.SYS, a Windows* WDM USB driver developed by In-System Design, Inc. (Note that this driver was written specifically to work with the In- System Design USB Smart Cable. For vendor- specific implementations, refer to the “Notes for Developers” in the Introduction of this Information Manual.) The purpose of USS720.SYS is to provide bulk data transfers and a mapping layer for the IEEE† 1284 registers over the Universal Serial Bus inter- face.

The purpose of this document is to:

■Define how USS720.SYS will interact with the Win- dows operating system components and the inter- face layer to other device classes.

■Provide a guide for using USS720.SYS.

Note: The USS-720’s Automatic Mode is recom- mended for almost all applications. The drivers included in the Lucent Technologies USS-720 Evaluation Kit use only Automatic Mode. Auto- matic mode implements all negotiation hand- shakes automatically for Compatibility, Nibble, and ECP modes. In Register Mode, the user must do the negotiations manually in software. Register Mode can be useful when imple- menting a nonstandard parallel port interface.

For more information on the Windows system-level components, USB architecture, and 1284 hardware, please refer to:

■Microsoft Win32 SDK (October 96 or later), avail- able from Microsoft *.

■WDM Driver Model Specification, available from Microsoft.

■WDM USB Driver Specification, available from Microsoft.

■USB Device Class Definition for Printing Devices, from usb.org web site.

■USS-720 USB-to-IEEE1284 Bridge Preliminary Data Sheet (DS98-393CMPR), available from Lucent Technologies Microelectronics Group.

■IEEE Standard Signaling Method for a Bidirectional Parallel Peripheral Interface for Personal Comput- ers (IEEE Standard 1284-1994)

Figure 1 provides a point of reference for directions mentioned in this document.

	USB	USS-720 IN
HOST PC		PERIPHERAL
	BULK OUT
OUTPUT		INPUT
DRIVER
INPUT		OUTPUT
	BULK IN

5-6005.r2

Figure 1. Signal Directions

*Windows and Microsoft are registered trademarks of Microsoft Corporation.

†IEEE is a registered trademark of The Institute of Electrical and Electronics Engineers, Inc.

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