USB4: Higher Performance and Combined Data

VIP Expert

Mar 19, 2019 / 3 min read

The most awaited news of the year is officially here! USB Promoter Group has officially announced USB4 specification, which is an extensive upgrade over USB 3.2 specification. The new specification guarantees double the speed of USB 3.2 Gen 2×2, and has built in Thunderbolt™ 3 compatibility. The official specification release is expected by mid-2019.

Aligning with the USB-IF’s announcement,  Synopsys also announced Industry’s First USB4 Subsystem Verification Solution, VIP, and Test Suite for High-performance USB Architecture. The Synopsys press release mentioned, “USB4 represents a significant specification update that will require a robust certification program to ensure delivery of compliant and interoperable USB devices in the consumer market,” said USB-IF president and chief operating officer Jeff Ravencraft. “Synopsys VIP for USB4 strengthens the USB ecosystem and facilitates early adoption and rapid development of the high-performance next-generation USB architecture.”

The new specification will use the existing USB Type-C connector/cable assembly, accentuating USB IF’s push towards a rapidly evolving USB Type-C ecosystem. USB4 will use USB Type-C’s dual Differential Pin assembly to generate dual lane data at the new data rates, however it will be possible with the compliant cables only.

“The primary goal of USB is to deliver the best user experience combining data, display and power delivery over a user-friendly and robust cable and connector solution,” said Brad Saunders, USB Promoter Group Chairman, in a press statement.

The above statement and adoption of Thunderbolt clearly hints that USB4 comes with the capability of running numerous Display devices along with conventional USB traffic, where USB Controller can manage and share the available bandwidth using optimization algorithms.

Pivotal details from the USB4 announcement:

1. Speed: The USB4 maximum data rate has now doubled to that of USB3.2 speed. Dual-lane technology over a Type-C cable can achieve maximum rates of up to 40 Gbps. USB4 technology is backward compatible and would be applicable to all existing cables, devices, hubs and bridges. Below is a speed comparison of all the USB versions:

USB speed comparison for USB4 data, display, and power

2. Thunderbolt™ : Intel’s Thunderbolt™ specification recently became open-source, making the integration of Thunderbolt and USB4 easier. The main motive behind this integration is to enable USB4 to leverage the popular Thunderbolt eco-system. New devices with Thunderbolt over USB4 are expected to become cheaper, and the USB interface would be adaptable to more display devices and GPU boxes, courtesy to the royalty-free Thunderbolt.

 

3. Bandwidth Optimization: The press release also announced the introduction of a mechanism to share bandwidth and traffic prioritization. More details are anticipated, but the expectation is that USB4 would have a daisy-chain mechanism where a certain bandwidth would be distributed and managed among multi-protocol peripherals. This would certainly be applicable to display related peripherals, but which other devices will be supported is yet to be seen.

 

There would be considerable upgrades in USB Type-C and USB Power Delivery specifications also, considering the expected changes in Power Ratings, Capabilities, and other Vendor specific parameters. Final branding, marketing logos and other technical details are expected in the coming months.

Synopsys’ Complete Verification Solution for USB

Synopsys is the market leader for IP and VIP for USB. We are the only provider of a complete verification solution for USB including the industry’s first subsystem verification solution, VIP, and source code Test Suite for USB4.  Synopsys was the first in industry to deliver VIP and source code Test Suite for USB 3.2 and USB Power Delivery 3.0. In addition, Synopsys worked with early adopters of USB Type-C – read about ASIX’s Adoption of Synopsys USB Type-C Subsystem Verification Solution​. The complete USB verification solution from Synopsys also includes VIP and source code Test Suite for USB 3.1/3.0/2.0 and Power Delivery 2.0. We are working closely with the early adopters of USB4, and contributing significantly to the evolution of the USB ecosystem. For more information, please visit http://synopsys.com/vip.

USB Type-C environment for USB4 data, display, and power

USB Type-C is a trademark of USB Implementers Forum. Thunderbolt™ is a trademark of Intel Corporation or its subsidiaries in the U.S. and/or other countries.

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