Massively open eye pattern

Notices where this attachment appears

1. Embed this notice
   Andrew Zonenberg (azonenberg@ioc.exchange)'s status on Tuesday, 24-Dec-2024 21:21:22 JST Andrew Zonenberg

   in reply to

   Time domain simulation says yes: it's completely fine. The eye is big enough you could drive a truck through it.

   Using +/- 300 mV swing at the TX it passes the QSGMII RX eye mask with a massive amount of margin and zero mask hits.

   Obviously the real eye won't be this pretty as there will be losses in the cable, but those will probably dominate whatever my board layout did to the signal.

   I could repeat the model doing channel emulation with actual waveforms coming off a Kintex-7 GTX at 5 Gbps through a half meter or so of coax, but with results this good it's not going to change anything.

   Might do it anyway just for fun.