Mandate: Required
Effective Date: April, 2005
The success of USB has been achieved by ensuring a consistent, reliable and enjoyable consumer experience. Translated, this means USB devices "just work." Consumers have come to expect a USB device to become quickly available and usable when attached to the bus. Now, with USB expanding into an ever widening array of applications and industries, it is important to continue to meet the consumer's expectations regarding USB in these new applications.
The USB-IF enforces a "no silent failure" rule. This means that an implementation of USB must not appear broken to the consumer. In configurations where the consumer's expectations are not met, either the peripheral or host must provide appropriate and useful feedback to the consumer regarding the problem.
Example 1:
Embedded hosts are, by definition, limited in capabilities. Should a consumer attach, to an embedded USB host, a USB peripheral that is not supported, nothing will happen. Without appropriate messaging, frustration and negative experience can occur as the consumer attempts to troubleshoot why the peripheral does not work. In this example, the embedded host would be the device to display an appropriate message informing the user that the device is not supported. Thus, embedded hosts are required to communicate a message to the consumer when an attached peripheral is not supported. The message should be specific and helpful for the consumer.
Example 2:
High-speed devices are required to enumerate and operate when attached to a full-speed port. However, there are some devices that require bandwidth far greater than 12Mbps making them useless at full-speed. Examples include high-speed video cameras that stream uncompressed, high resolution content. Without appropriate messaging, the consumer would either see garbled video or no video at all with such a camera attached at full-speed. In this example, the camera would be the device responsible for displaying an appropriate message to the consumer.
Different messages for hubs and non-hubs are required. If the attached peripheral is a hub, the embedded host must be able to display a message indicating that the attached hub is not supported. Care should be taken to distinguish between standalone hubs and compound peripherals. If an unsupported hub is attached, the embedded host should read bit D2 the wHubCharacteristics field of the hub descriptor and display the appropriate message in case the attached hub is part of a compound peripheral.
Top Mandate: Required
Effective Date: Now
Some vendors insert variable place holders (typically with an 'X') in the model number to denote different features of a product. For example, a product that comes in two colors, black and white, may have model numbers 123B and 123W. Since the feature is cosmetic, the USB-IF allows the use of a variable in the color field, such as 123X, on the Integrators List.
The USB-IF does not permit variables to represent features that can affect USB compliance. For example, if a vendor has a full-speed and a high-speed version of a product, the model number placed on the Integrators List cannot use a variable in the model number to represent the speed of the product.
The naming convention for devices, silicon, cables, connectors, etc. must be clear and identify only certified product.
USB connectors and USB cable assemblies are prohibited from using wildcards in their model names.
Top Mandate: Optional
Effective Date:
If a standard USB peripheral does not support SRP, then the OTG Descriptor must not be included with the GetDescriptor(configuration) data set.
HNP is reserved for USB On-The-Go devices and is not permitted in embedded USB hosts and standard USB peripherals. HNP is the identifying function of OTG.
An embedded host should not attempt to enable an OTG peripheral for HNP. This could cause unexpected behavior of the OTG peripheral. Execution of the OPT test TD.4.5 "A-UUT is Reset//Enumerated as Peripheral After HNP" is required to determine if the non-OTG embedded host attempts to use any OTG functions.
The Micro-USB AB-receptacle is reserved for USB On-The-Go devices only and is not permitted in devices that do not support HNP. The Micro-USB AB-receptacle is the identifying feature of OTG.
Top Mandate: Required
Effective Date: February, 2007
If the VID of a product does not match the VID of the integrator, the USB-IF will not permit the device to be added to the Integrators List.
If the integrator has permission to use the VID of the other company, then written permission from the other company must be included with the checklist submission to the USB-IF. With written permission, the device may be listed on the Integrators List.
Top Mandate: Informational
Effective Date:
- Violation's effect on end-user experience
- Violation's affect on other USB product
- Market share of affected product
- Cost of corrective action to the vendor
Top Mandate: Informational
Effective Date:
Top Mandate: Informational
Effective Date: n/a
The USB-IF has an active program to address improper use of its trademarks and will audit devices that display the Certified USB Logo. If a commercially available product is suspected of violating USB-IF compliance requirements, contact the USB-IF. Please provide specific examples of the alleged non-complying merchandise including:
- Manufacturer Name
- Product Name
- Model Number or Part Number
- Revision
- Retail location where the product can be obtained
- Detailed description of how you believe the product is not compliant
- Photographs of the product displaying the Certified USB Logo.
We will evaluate whether appropriate action should be taken.
Send all appropriate information to Admin@usb.org. Please note that the USB-IF will keep your information confidential.
Top Mandate: Required
Effective Date: August, 2008
Qualification by Similarity
The USB-IF offers a Qualification by Similarity program to member companies. The QbS program allows a USB product that is substantially similar to a fully tested and certified USB product to be granted certification based on its similarity to the originally certified product. The purpose of the QbS program is to speed time-to-market and to minimize certification costs. It is not intended to eliminate the requirement that a product actually passes USB-IF compliance tests.
Policy
The only authority to grant Qualification by Similarity to a product is the USB-IF compliance committee and the certification review board. No test facility or any other entity is authorized to grant or pursue Qualification by Similarity requests on behalf of the USB-IF.
The new product must be similar to a USB certified product that has undergone full and complete compliance testing. The new product cannot be compared to another product that itself has been granted Qualification by Similarity.
If the original certified product on which the Qualification by Similarity is based is older than 3 years, then a complete and full retest is required of the new product.
Procedure
- Member companies submit a Qualification by Similarity request using the form at http://www.usb.org/kcompliance/similarity/
- When applicable, the USB-IF will obtain specification sheets/drawings of both the originally certified and new products
- A review of the QbS request and specification sheets/drawings will be performed by the USB-IF compliance committee. One or more of the authorized test labs and/or other experts in a given field may be consulted.
- The USB-IF will issue its assessment to the vendor. One of three outcomes is possible:
- Qualification by Similarity is granted and no other action is required. A new TID will be issued to the new product
- Qualification by Similarity is denied. All certification tests are required for the new product
- Qualification by Similarity may be granted provided the new product passes a subset of specific compliance tests
- If the assessment requires passing a subset of compliance tests, the vendor will be informed of the required tests in an email from the USB-IF that includes a ReplyID number
- The vendor will submit the product for testing to the authorized test lab of their choice along with a copy of the email
- The test lab should request a copy of the specification drawings from the USB-IF to verify that the product submitted for testing matches the drawings. Please use the ReplyID number when requesting the drawings.
- The authorized test lab performs only the tests identified in the email
- Upon successful completion of the tests, the authorized test lab will send an email to TechAdmin@usb.org along with the test results and the ReplyID number.
- If the product passes all required tests, then the USB-IF will grant Qualification by Similarity to the product, issue a TID number and add the product to the Integrators List.
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