End-to-End USB Validation and Test Programs Enable Faster Development of Reliable USB-Compliant Peripheral Products

ABSTRACT
The Universal Serial Bus (USB) offers unprecedented peripheral expandability and ease of use for PC users. For peripheral manufacturers, USB opens the door to a variety of new value-added features, as well as new methods of marketing which can lead to new customers and sales. Fueled by the demand for easier-to-use PCs, USB technology has quickly evolved from a technical concept into a host of real-world USB-compliant PC systems and peripheral products. As with most new PC-related technologies, consumer acceptance of USB will be a crucial determinant of success. For PC manufacturers and peripheral suppliers alike, the reliability and compatibility of USB products are the pivotal factors which will influence the popularity of this new technology with consumers. Well-defined product validation procedures are now in place which allow OEMs to thoroughly test and verify the ability of USB devices to interface with Intel's PCIset-based host controllers. These validation steps make it possible for developers to launch products and commit to new marketing strategies with a high degree of confidence.

THE PROBLEM: MAKING SURE USB WORKS
USB technology will redefine the way PC users relate to peripheral products. Such capabilities as plug-and-play, hot attach/detach and auto-configuration make adding a new peripheral literally as easy as reaching for the plug. In addition, USB's single connector type and hub-based tiered-star topology will make it easy for users to manage peripherals on the desktop. An entire new generation of USB-compliant PC systems and peripherals will soon be available to consumers, with a virtually infinite number of bundling strategies available to OEMs and resellers. To deliver on the promise, USB peripherals must work as advertised, every time they are plugged in.

THE SOLUTION: END-TO-END USB VALIDATION
Intel has adopted a rigorous end-to-end validation methodology to assure that USB reliability and compatibility goals are achieved. Intel PCI chip sets, including the 82371SB PCI/IO IDE Xcelerator (PIIX3) with integrated USB host controller, have been widely adopted by the world's leading PC manufacturers. The special tools developed by Intel for system validation of the USB host controller also support the validation of USB peripheral controllers. These tools enable complete control of the USB host, for thorough validation and testing. What's more, product developers can use the same test and validation software now employed by Intel for comprehensive USB specification compliance. This includes verification of USB compatibility for PC systems with Intel PCIsets and peripherals with the Intel 8x930 family of peripheral controllers.

PRE- AND POST-SILICON VALIDATION OF USB DEVICES
The overall design of Intel USB semiconductor products is conducted in three major phases: product definition, product implementation (including pre-silicon validation) and finally post-silicon product verification. The product implementation phase includes a series of well-defined validation steps to help assure ultimate USB product reliability. These steps include validation of the hardware design for conformity with the specification, full-chip simulation at the unit level within design boundaries, system-level simulation of the design involving real-world firmware working with a bus functional model, and quick-turn emulation of the design within the system environment.

Post-silicon system validation involves testing USB components with specialized hardware and software within a system environment. An important element of the process is USB compatibility validation testing. This step includes testing with operating systems, device class drivers and applications software on USB host controller-equipped PC platforms. The objective of post-silicon validation is to uncover potential issues prior to production, so that no silicon problems exist for customers.

THE INTEL 8x930 EVALUATION BOARD
Intel has developed a USB Function Validation Standard incorporating the 8x930 Evaluation Board. The Evaluation Board is used by developers of USB peripheral products worldwide, and it is also used within Intel for:

Development of 8x930 firmware and validation tests,
Validation of new USB host controllers with Intel PCIsets;
Production testing of USB motherboards;
Testing of OEM system compatibility and interoperability

The the 8x930 Evaluation Board is also used for development and validation of USB drivers and device class drivers at Microsoft.

END-TO-END VALIDATION TESTING
To validate compatibility between USB hosts and peripheral devices, Intel has developed tests for the USB 1.0 device framework, protocol layer and hub specifications. These comprehensive tests are designed to verify that Intel USB products do what they are intended to do.

A PREFERRED SOLUTION: THE 8x930Ax USB PERIPHERAL CONTROLLER
The Intel 8x930Ax USB peripheral controller is the world's first USB specification 1.0-compliant single-chip controller. It is also the first in a growing family of USB peripheral controller solutions designed from the outset to interface with Intel PCIset-based USB host controllers. The 8x930 family also includes the Intel 8x930Hx USB Hub microcontroller. Intel 8x930 USB peripheral controllers are the preferred hardware solution for more than 200 USB peripheral devices now in development.

USB FIRMWARE CODE
As part of its applications support program for peripheral product developers, Intel provides USB firmware source code for the 8x930Ax and 8x930Hx USB peripheral controllers. This standard code module handles the most basic USB transactions with the USB host controller. Using Intel firmware means developers can concentrate on adding device functionality, without worrying about developing their own firmware from scratch.

DEVICE CLASS DRIVERS TEMPLATES
The Intel 8x930 Evaluation Board is now being used at Microsoft for USB driver and device class driver development. To assist peripheral developers, Intel provides a ready-made device driver template that conforms to the Microsoft Windows* driver model.
HOSTWARE AND DEVELOPMENT TOOLS
USB peripheral developers can employ the same tools used within Intel to assure ultimate product reliability. In addition to the 8x930 Evaluation Board, developers can use a suite of software tools including USB hostware, the Intel ApBUILDER design tool, as well as an assembler, C compiler and debugger. The evaluation board and software are available in kit form, together with a Users Guide, USB cables and documentation. USB Reference Designs are also available.

CONCLUSION
Compatibility and reliability are critical issues for developers of USB peripheral products. End-to-end peripheral validation and testing with Intel PCIsets, USB peripheral controllers and development tools is a system solution that can help developers build consumer acceptance and market USB peripherals with a high degree of confidence.

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