USB-IF Compliance Updates

Number of Updates: 16

Table of Contents
ID Updated Subject Reason Mandate Effective Date
145 March, 2022 Qualificaiton by Similarity Program: USB PD products must be tested agasint the new PD CTS Update to USB PD CTS Required March, 2022

130 September, 2019 Products Capable of Operating with External Power and UFP Power Must be Tested in both Configurations Ensuring Products Meet User Expectations with Varying Available Power Required August, 2019

126 May, 2019 Test Solution Approval Requirements Required May, 2019

124 May, 2019 Multiple Upstream Facing Ports Introduction of USB Type-C Informational May, 2019

122 March, 2019 Products containing an eSATAp port are not eligible for certification Exposing USB functionality over an undefined USB interface is prohibited Required

110 April, 2017 Thermoplastics for USB Type-C (TM) Clarification on Required Material Required April, 2017

94 July, 2014 Grace Period after the Introduction of a New Test Policy statement Required July, 2014

77 January, 2012 USB 3.0 Based Products Seeking SuperSpeed Certification Must use Certified USB 3.0 Connectors Announcement that beginning 01 Sept 2011, USB 3.0 products must use certified USB 3.0 connectors. Required September, 2011

72 October, 2010 Peripheral Power Consumption Clarification on maximum power draw by USB peripherals Required Now

14 January, 2010 Model number feature identification conventions Model numbers placed on Integrators List must clearly identify the certified product Required October, 2005

57 November, 2008 Qualification by Similarity Policy Statement Update to the USB-IF Qualification by Similarity Program Required August, 2008

29 July, 2007 USB-IF Certified USB Logo Trademark Violations How to contact the USB-IF regarding certified, non-compliant USB products Informational n/a

13 June, 2007 "No Silent Failure" policy Clarification of the "No Silent Failure" rule Required April, 2005

16 April, 2007 Vendor ID Usage Vendor IDs belong to the company to which it is assigned Required February, 2007

15 April, 2007 Use of certified On-The-Go (OTG) building blocks in non-OTG products Policy statement on OTG building blocks Optional

17 March, 2007 Waivers Policy Statement Informational

Thermoplastics for USB Type-C (TM)
Mandate: Required
Effective Date: April, 2017

Table 6-7 of the USB 2.0 Specification requires that thermoplastics have a rating of UL 94 V-0 or better. This requirement is also applciable to USB Type-C(tm) connectors.

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Products containing an eSATAp port are not eligible for certification
Mandate: Required
Effective Date:
Products containing an eSATAp port are not eligible for certification. Exposing USB functionality over an undefined USB interface is prohibited.
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Multiple Upstream Facing Ports
Mandate: Informational
Effective Date: May, 2019

Typical USB topology allows Hosts and Hubs to have multiple downstream facing data ports while limiting peripherals to only have one upstream facing data port. Prior to the introduction of the USB Type-C specification the USB-IF compliance program enforced that all peripherals have only one upstream facing data port. With the introduction of the USB Type-C specification the USB-IF compliance program will consider a waiver for specific implementations. A vendors implementation must meet all of the following conditions to be considered for a waiver. If the implementation has multiple upstream facing ports:

 

1.       At least one of the upstream facing ports must be USB Type-C

2.       The behavior of the other upstream facing port when one UFP is in use must be clearly documented for the end user. Products with displays may be expected to provide a message to the user.

3.       A physical mechanism to switch between each UFP or very clear labeling must be present on the device under test to avoid end user confusion.

 

The USB-IF compliance committee will review all waiver applications on a case by case basis. All waiver requests must include proof of the three requirements listed above.

 

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Test Solution Approval Requirements
Mandate: Required
Effective Date: May, 2019

All test solutions seeking USB-IF approval must meet the requirements listed in this update.

1.       Test solution vendors seeking approval must be USB-IF Members.

2.       Test solution companies must regularly attend and contribute to Working Group discussions.     

3.       Test solutions are only approved on a test specification level. A test solution cannot be approved if it implements only part of a test specification.

4.       If approved test solutions already exist, the test solution seeking approval must meet the following requirements:

a.       90% overall correlation against approved solution(s)

b.       90% correlation across each test case against approved solution(s)

c.       Sample size of a minimum of 50 products tested at workshops

d.       Minimum of 5 products of each product type defined in the test specification 

 i.      Note: the USB-IF will consider the availability of each product type during the correlation process. If a specific product type is not readily available or is uncommon these numbers may decrease.

5.       Test solution vendors participating in the initial and continuous development of a test specifications will be considered first in the approval process when new test specifications are published.

 

 

 

 

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"No Silent Failure" policy
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.

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Products Capable of Operating with External Power and UFP Power Must be Tested in both Configurations
Mandate: Required
Effective Date: August, 2019

Effective immediately all products that are Externally Powered and Upstream Facing Port (UFP) Powered must be tested completely in both the Externally Powered state and the UFP Powered state.

A product is UFP Powered when it draws power from its UFP port partner. This includes USB 2.0 and USB 3.2 defined bus-power, Battery Charging 1.2 power, USB Type-C power and USB PD power. This is defined in the USB Type-C? Product Test Matrix.

Before the introduction of USB Type-C and USB Power Delivery technologies there were two USB defined operational power states, bus-powered and self-powered. For products that reported themselves as self-powered and bus-powered their functionality could reasonably change depending on their power state. If a product reported itself as self-powered only, the amount of power and specific V*I it required was not tested or tracked by the USB-IF. Whether the product required 5W or 50W from its external power port did not matter for compliance as this was not done over a USB port. The only requirement was for vendors to provide the power adapter intended to be sold with the product under test (PUT). The USB-IF considered the bus-powered state the more strenuous state and prioritized compliance testing in the bus-powered state.

With the introduction of USB Type-C and USB Power Delivery technologies, USB now provides a method for products to use USB as their main source of power. What was once outside the scope of USB is now firmly within scope. The USB-IF compliance program must consider all power profiles and their affect on the PUTs behavior. While in the past functional differences between a product operating in bus-powered mode vs self-powered mode were minimal, today it has become increasingly more common for USB Type-C and USB PD products to vary their functionality widely based on available power. To avoid user confusion and silent failures a product must be tested with all combinations of power profiles to ensure user expectations are met.

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Model number feature identification conventions
Mandate: Required
Effective Date: October, 2005
The USB-IF Integrators List consists of Certified USB products. Only products that have passed required compliance tests are listed. The model number displayed on the Integrators List must clearly represent the certified product.

The USB-IF does not allow the use of a variables in the product name or model number. Some vendors want to use 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. Even though the differences are cosmetic, the USB-IF does not allow use of a variable to represent such differences.

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.

The USB-IF will allow multiple product names/model numbers to be listed under one Test ID (TID) number on the Integrators List if the differences are cosmetic. However, only one revision number may be used with a TID.
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Qualificaiton by Similarity Program: USB PD products must be tested agasint the new PD CTS
Mandate: Required
Effective Date: March, 2022

Effective immediately all products seeking certification through the QbS system will be required to test against the new USB PD CTS. The current version of the USB PD CTS at the time of this post is v1.4.

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Use of certified On-The-Go (OTG) building blocks in non-OTG products
Mandate: Optional
Effective Date:
Embedded hosts and standard peripherals may use certified On-The-Go building blocks provided OTG specific features are not exposed.

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.
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Vendor ID Usage
Mandate: Required
Effective Date: February, 2007
The Vendor ID used by a product must match the VID of the company producing the product (the integrator). Please ensure that the VID used by the product matches the company making the product. The USB-IF does not permit the product to display the silicon VID instead of the company making the product.

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.
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Waivers
Mandate: Informational
Effective Date:
Vendors are expected to design to the USB specification and only devices that comply with the USB specification are able to use the logo. The USB-IF recognizes, however, that some violations are minor and have, effectively, no negative affect on the performance of the product. The USB-IF may grant a waiver to a device that violates the USB specification or fails a certification test. Although rarely granted, the waiver forgives the violation and permits the device to use the official logo.

Waivers are only granted at USB-IF sponsored workshops or when submitted via a USB-IF authorized test facility. We need to verify and assess the nature of the problem first-hand and with independent test data. The USB-IF may discuss the possibility of a waiver with a vendor without independent test data, but opinions stated are not binding and are subject to change based on official data collected at the time of testing.

The criterion for granting a waiver varies greatly and tends to be specific to the device. Some general factors used to consider granting or denying waiver requests are:

  • 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
Waiver decisions are at the discretion of the USB-IF Compliance Chairman and members of the Certification Review Board.

Waivers may not be publicized without written permission of the USB-IF.

A waiver is applied to a TID of a particular device and cannot be propagated or transferred to other devices without permission of the USB-IF. Waivers cannot be granted to devices that do not have a Test ID (TID) assigned to them.

Waivers are not granted to devices that have multiple violations.

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USB-IF Certified USB Logo Trademark Violations
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.

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Qualification by Similarity Policy Statement
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

  1. Member companies submit a Qualification by Similarity request using the form at  http://www.usb.org/kcompliance/similarity/
  2. When applicable, the USB-IF will obtain specification sheets/drawings of both the originally certified and new products 
  3. 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.
  4. The USB-IF will issue its assessment to the vendor.  One of three outcomes is possible:
    1. Qualification by Similarity is granted and no other action is required.  A new TID will be issued to the new product
    2. Qualification by Similarity is denied.  All certification tests are required for the new product
    3. Qualification by Similarity may be granted provided the new product passes a subset of specific compliance tests
  5. 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
  6. The vendor will submit the product for testing to the authorized test lab of their choice along with a copy of the email
  7. 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.
  8. The authorized test lab performs only the tests identified in the email
  9. 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.
  10. 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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Peripheral Power Consumption
Mandate: Required
Effective Date: Now
The maximum current that any USB peripheral is permitted to draw from a standard USB 2.0 downstream port is 500mA. This includes USB 3.0 peripherals and peripherals that charge batteries from USB. For this discussion, a standard USB 2.0 downstream port complies with the definition of a host or a hub as defined solely in the "Universal Serial Bus Specification," Revision 2.0 document.

The maximum current that a USB 3.0 peripheral may draw from a standard USB 3.0 downstream port is 900mA. USB 2.0 peripherals and USB 2.0 peripherals that charge batteries from USB are still limited to 500mA when attached to a standard USB 3.0 downstream port. For this discussion, a USB 3.0 standard downstream port complies with the definition of a host or a hub as defined solely in the "Universal Serial Bus 3.0 Specification," Revision 1.0 document.

Use of a 'Y' cable (a cable with two A-plugs) is prohibited on any USB peripheral. If a USB peripheral requires more power than allowed by the USB specification to which it is designed, then it must be self-powered.

All upstream ports are required provide enumeration of USB functions.
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USB 3.0 Based Products Seeking SuperSpeed Certification Must use Certified USB 3.0 Connectors
Mandate: Required
Effective Date: September, 2011
The USB-IF has always required USB 2.0 products to use certified connectors as a prerequisite to obtaining certification. This requirement is being extended to USB 3.0 based products where certified USB 3.0 connectors must be implemented in order to qualify for SuperSpeed certification.

As of September 01, 2011, all products seeking SuperSpeed certification must use certified USB 3.0 connectors. This requirement applies to any USB 3.0 device with exposed USB connectors including reference platforms for building blocks. This requirement also applies to SuperSpeed cable assemblies and SuperSpeed products that have a captive cable assembly. Please note that cable assemblies that are shipped with a certified SuperSpeed product must also be SuperSpeed certified.
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Grace Period after the Introduction of a New Test
Mandate: Required
Effective Date: July, 2014
Once a test that affects silicon is introduced into the USB certification program, a grace period of 12 months will be granted for silicon vendors to comply with the test. End products will be granted 18 months from the introduction of the test to comply with the requirement.
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