USB Cheat Sheet (2022)

#1

Post by gwerbret » Sat, Apr 25, 2026, 9:51 PM UTC

USB Cheat Sheet (2022)
fabiensanglard.net

Re: USB Cheat Sheet (2022)

#2

Post by brcmthrowaway » Sat, Apr 25, 2026, 11:09 PM UTC

Where does TB5 come into all of this?

Re: USB Cheat Sheet (2022)

#3

Post by 15155 » Sat, Apr 25, 2026, 11:12 PM UTC

Good sheet. Worth adding:

- Female vs male crossover naming and pinouts for Type-C connectors

- Actual voltage, modulation and signaling schemes (USB4v2 uses PAM3 11b/7t encoding)

- PD generations and profiles

Re: USB Cheat Sheet (2022)

#4

Post by mschuster91 » Sat, Apr 25, 2026, 11:15 PM UTC

15155 wrote: post #3

Good sheet. Worth adding: - Female vs male crossover naming and pinouts for Type-C connectors - Actual voltage, modulation and signaling schemes (USB4v2 uses PAM3 11b/7t encoding) - PD generations and profiles

... and the bunch of proprietary voltage schemes like Quickcharge.

Re: USB Cheat Sheet (2022)

#5

Post by Neywiny » Sat, Apr 25, 2026, 11:17 PM UTC

I actually like the 3.2 naming. Gen is speed, "by" is width. It puts it very roughly on par with PCIe's naming which nobody complains about. I just don't like that USB 3, USB 3.1, and USB 3.2 are the same things. And that sales people don't seem to understand that saying a chip supports 3.1 or 3.2 tells me it's anywhere from 5-20gbps which isn't ideal.

Re: USB Cheat Sheet (2022)

#6

Post by Neywiny » Sat, Apr 25, 2026, 11:18 PM UTC

brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

I don't see why it would. Thunderbolt is not a USB standard

Re: USB Cheat Sheet (2022)

#7

Post by Kirby64 » Sat, Apr 25, 2026, 11:25 PM UTC

Neywiny wrote: post #6

brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

I don't see why it would. Thunderbolt is not a USB standard

Thunderbolt 5 and USB4v2 are the same thing now. They both support 80gbps and pcie pass through.

Re: USB Cheat Sheet (2022)

#8

Post by mistyvales » Sat, Apr 25, 2026, 11:26 PM UTC

Neywiny wrote: post #5

I actually like the 3.2 naming. Gen is speed, "by" is width. It puts it very roughly on par with PCIe's naming which nobody complains about. I just don't like that USB 3, USB 3.1, and USB 3.2 are the same things. And that sales people don't seem to understand that saying a chip supports 3.1 or 3.2 tells me it's anywhere from 5-20gbps which isn't ideal.

PCI-E has had the same standard since its inception: 1.0, 2.0, 3.0, etc. USB has changed multiple times and has remained confusing for the vast majority of people. What was 3.0 is now not 3.0. Even 3.1 has changed. There is no reason to use this naming convention they currently have but for some reason they stick with it..

Re: USB Cheat Sheet (2022)

#9

Post by stevex » Sat, Apr 25, 2026, 11:27 PM UTC

Neywiny wrote: post #6

brcmthrowaway wrote: post #2

Where does TB5 come into all of this?

I don't see why it would. Thunderbolt is not a USB standard

Doesn't it run over a USB-C shaped wire? If you're trying to understand things that plug into USB-shaped ports it seems at least worth mentioning.

Re: USB Cheat Sheet (2022)

#10

Post by DHowett » Sat, Apr 25, 2026, 11:32 PM UTC

Excellent article.

If I could offer one correction, it would be that SBU (as specified by the USB 3.0 Promoter Group[1]) means "Sideband Use" rather than "Secondary Bus".

On some devices, it is used to carry UART; on others, audio.

[1]: https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%... (pdf)