Gregory's Server
@azonenberg @gsuberland the cursed thing about USB4v2 is that it uses PAM3 on the physical layer.
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4 comments
 @azonenberg @karotte @funkylab @gsuberland just out of curiosity, what stops you from configuring the transceivers to PAM-4 and then just not using either the top or the bottom level? Do you get into trouble with level symmetry?  @jaseg @karotte @funkylab @gsuberland For TX, I think it would work. For RX, I think you'd run into problems with asymmetry and the baseline wander correction putting your thresholds in the wrong place. @jaseg @karotte @funkylab @gsuberland (also even PAM4 transceivers are really rare, only like the biggest virtexes have them right now) |
@karotte @funkylab @gsuberland Yes, PAM3 is annoying.
Especially because ~nothing COTS can do PAM3 so there's no hope of speaking it with an FPGA transceiver etc.