USB-C to HDMI and DP Source and Sink Compatibility

[Nick]

Hello, I am trying to build a circuit that will accommodate USB-C with HDMI as either a source or a sink depending on the device connected. I would also like to be able to use the same circuit to do the same thing with USB-C and Display Port. Not sure if the CYPD3125-40LQXI can be used to do this? 

I believe these circuits only work as a sink or source and cannot change between them?

https://www.cypress.com/documentation/reference-designs/ez-pd-ccg3-usb-type-c-hdmi-adapter-solution

https://www.cypress.com/documentation/reference-designs/ez-pd-ccg3-usb-type-c-displayport-cable-solu...

If the CYPD3125 replaced the CYPD3120 in these above circuits would this now work as a sink and source?

If there is a link to a schematic or a way this can be done I would greatly appreciate it, thanks!

[Sananya_14 · Accepted solution]

Hello,

CCG3 currently either has a DP source or DP/HDMI sink implementation in the firmware and corresponding schematic with unidirectional MUX (in case of receptacle design), HPD, AUX connections. The Host SDK firmware for CYPD3125 includes DP source only implementation and you could refer to this blog to have a DP sink only implementation, but there is no example firmware or schematic to have both DP/HDMI source and sink implementation on CCG3.

To have both implemented together, you would have to ensure a few things based on the DP source or sink mode for e.g. the DP lanes are routed correctly to the pins on the Type-C connector, configuration includes supported pin assignment, AUX lines have appropriate terminations and HPD is configured as output or input in the firmware.

Best Regards,
Sananya

[OlEr_1999891]

Hi!

Turning CCG3 into a DP Sink is just a matter of changing the mux to a Sink-version instead (e.g. PS8742 instead of PS8743) and change the macros as outlined in the blog. To have CCG3 as both a DP Sink & Source you need to find a mux that can work bi-directional. I have only found one (TI HD3SS460), but there would be some firmware work. Note that the reason that almost all Type-C mux'es are uni-directional is because they have built-in redrivers. The TI above is a passive mux. 

Support HDMI alt-mode at the same time as DP alt-mode I'm not sure it is even possible. You would need to find a mux that can do that and I haven't seen one.

Note that no one is using HDMI alt-mode on the market. No laptop or mobile put out that what I know of.