Other Parts Discussed in Thread: TUSB564
Hi USB-C team,
My customer is using TUSB564. They are planning on supporting DP alt mode (as UFP). They are also planning on supporting DRD too though.
They are new to USB-C and need some guidance on how does all of this work (DP alt mode).
Based on the following:
https://www.quantumdata.com/assets/displayport_linklayer_compliance_webinar.pdf
The assumption is this:
- PD controllers talk – tell each other they support DP alt mode (as source or sink).
- Presumably source side says – let’s do video, go switch.
- Sink configures its crosspoint for “Config C” (4-lanes DP).
- Sink ACK’s (“video switched we’re good now”).
- Source configures its crosspoint for “Config C” (4-lanes DP).
- Training begins on a lane-by-lane basis.
- Crosspoint on both sides will automatically (due to snooping) change to “Config D” (2-lane DP) if applicable.
- Assuming crosspoints have re-configured as 2-lane DP, USB 3 will enumerate (SS TX/RX connect).
Both of these crosspoints are configured for I2C mode.
Is this what happens in general? Ist here any documentation that describes this process or some helpful info? Anything they need to watch out for?
I had to redact some info to preserve their product IP, please reach out to me via email internally if you need more clarification.
Thanks,
Lauren
