Is it possible to use Shared Link for a USB3 + USB2 device that are both contained in a single pluggable module connected with USB Type-C?

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
JoIs_3887151
Level 1
Level 1
Welcome!

I have a system with a custom USB-C hub/interface board that supports many test modules. Each test module contains a USB3 device and USB2 device. Shared Link would be attractive if I could connect each of these test modules to a single port in a Cypress hub on the hub/interface board.

I see that the HX3 datasheet requires separate VBUS controls for the embedded devices. Could the system meet this requirement by sending VBUS control info over the SBU pins after negotiating a proprietary alternate mode over USB Type-C PD?

I see that Shared Link requires that the USB3 device be present from power-up onward. Is there a firmware-accessible reset that our hub/interface board processor could trigger when one of our devices is plugged in? If not, would the system work if we only power-up the HX3 when all devices are stable and somehow disable ports that do not have USB3 devices when we power up?

Thank you,

Jon

0 Likes
1 Solution
RajathB_01
Moderator
Moderator
Moderator
250 replies posted 100 replies posted 50 replies posted

Hi Jon,

Are you using a Type-C controller for handling the flip? Does it include PD for power delivery (and not alternate mode)?

1) If you are not using the SBU channel for anything else, you can directly just route the VBUS_EN and PWREN signals over SBU1 and SBU2. No need of Alternate Mode negotiation over PD. Then on your module you can recieve the VBUS control signals from SBU1/2 and provide it to the onboard switches.

2) You can verify with the method of first connecting your module over Type-C and then powering your Hub interface board. That should work.

Then we can implement a reset on connect. I'll get back to you with more information on firmware accessible reset and other options.

Regards,

Rajath

View solution in original post

0 Likes
5 Replies
RajathB_01
Moderator
Moderator
Moderator
250 replies posted 100 replies posted 50 replies posted

Hi Jon,

Are you using a Type-C controller for handling the flip? Does it include PD for power delivery (and not alternate mode)?

1) If you are not using the SBU channel for anything else, you can directly just route the VBUS_EN and PWREN signals over SBU1 and SBU2. No need of Alternate Mode negotiation over PD. Then on your module you can recieve the VBUS control signals from SBU1/2 and provide it to the onboard switches.

2) You can verify with the method of first connecting your module over Type-C and then powering your Hub interface board. That should work.

Then we can implement a reset on connect. I'll get back to you with more information on firmware accessible reset and other options.

Regards,

Rajath

0 Likes

Hi Rajath,

Thank you for the response, it is very helpful! I've ordered the CY4613 dev kit and will plan to use SBU for VBUS_EN and PWREN.

Am looking forward to further information about firmware accessible reset and other options.

Best Regards,

Jon

0 Likes

Hi Jon,

I can suggest you to do the HX3 hub external reset whenever a connect event occurs on the Type-C port(s).

Unfortunately a firmware accessible reset from an interrupt generated by other cpu's is not possible.

If you are using a Type-C port controller, it can generate a reset signal for the hub when a device is attached.

Please provide details if any on the Type-C port controller if you are using.

Regards,

Rajath

0 Likes

Hi Rajath,

I am thinking of the CCG6 as the type-C & PD controller. I need 20V support and may need 100W. It looks like the CCG3 would also be an option.

Thank you,

Jon

0 Likes

Hi Jon,

I would suggest to drive a GPIO from the CCG that can reset the hub on its RESETN pin.

CCG can generate this signal from its firmware whenever a Type-C connect event occurs (or any other event for which you might need a reset).

Regards,

Rajath

0 Likes