Industry Expert Blogs
USB4 Sideband Channel Is Not a Side Business-November 28, 2024 |
The USB4 specification has been around for several years now. Two years ago, USB4 version 2.0 was also released by the USB Promoter Group. This specification enables up to 80Gbps link speed per direction in symmetric mode and 120Gbps link speed in asymmetric mode.
Be it Gen 2, Gen 3, or Gen 4 link speeds of 20Gbps, 40Gbps, 80Gbps, or 120Gbps, the sideband channel is indispensable for the stable operation of the high-speed link. It plays a multi-faceted role.
The sideband channel is a simple two-wire low-speed link operating at 1Mbps using 10-bit start/stop encoding that does not require any synchronization of its own. It supports different transaction types, namely, Link Type (LT), Administrative Type (AT), and Re-timer Type (RT), each having their specific roles mentioned in the table below.