USB 3.2 DOUBLES the data transfer capabilities of previous USB specifications, and could mean the end of having USB ports on just one side of your computer. Find out more in today’s electrical engineering podcast with Jit Lim, Daniel Bogdanoff, and Mike Hoffman.
Jit is the USB and Thunderbolt lead for Keysight.
USB 3.2 specifications were released Fall 2017 and released two main capabilities.
USB 3.2 doubles the performance of USB 3.1. You can now run 10Gb/s x2. It uses both sides of the CC connector.
In the x2 mode, both sides of the connectors are used instead of just one.
The other new part of USB 3.2 is that it adds the ability to have the USB silicon farther away from the port. It achieves this using retimers, which makes up for the lossy transmission channel.
Why laptops only have USB ports on one side! The USB silicon has to be close to the connector.
If the silicon is 5 or 6 inches away from the connector, it will fail the compliance tests. That’s why we need retimers.
USB is very good at maintaining backwards compatibility
The USB 3.0 spec and the USB 3.1 spec no longer exist. It’s only USB 3.2.
The USB 3.2 specification includes the 3.0 and the 3.1 specs as part of them, and acts as a special mode.
From a protocol layer and a PHY layer, nothing much has changed. It simply adds communication abilities.
Who is driving the USB spec? There’s a lot of demand! USB Type C is very popular for VR and AR.
There’s no benefit to using legacy devices with modern USB 3.2 ports.
There’s a newly released variant of USB Type C that does not have USB 2.0 support. It repurposes the USB 2 pins. It won’t be called USB, but it’ll essentially be the same thing. It’s used for a new headset.
USB Type C is hugely popular for VR and AR applications. You can send data, video feeds, and power.
Richie’s Vive has an audio cable, a power cable, and an HDMI cable. The new version, though, has a USB Type-C that handles some of this.
USB 3.2 will be able to put a retimer on a cable as well. You can put one at each end.
What is a retimer? A retimer is used when a signal traverses a lossy board or transmission line. A retimer acquires the signal, recovers it, and retransmits it.
It’s a type of repeater. Repeaters can be either redrivers or repeaters. A redriver just re-amplifies a signal, including any noise. A retimer does a full data recovery and re-transmission.
What is your favorite alt mode, and why?
If you could rename Type-C to anything, what would you call it?