Does STUSB4500 support DR_Swap Message?

[WGao.1]

Hello,

When I connect USB-C source power to our device, PD sniffer shows Source:DFP sends DR_Swap message to our device, which has a STUSB4500 PD controller. However, our device(Sink:UDP) always sends Reject command.

My questions are:

• Does STUSB4500 support DR_Swap message?
• We want to swap data role based on PD negotiation, how to get the message and how to process it to reply Accept?
• Is there a register that record the DR_Swap message?
• From STUSB4500, is there a way to trigger to have PD source to send the DR_Swap message again?

Thanks,

Winston

[Gregory Go. · Accepted solution]

Hello,

No the STUSB4500 doesn't support the DataRole_Swap message.

The STUSB4500 role is a Power Sink. And following the USB PD specification, a Power Sink always start as UFP (Device).

If you want to change the default role, you need indeed to send a PowerRole_Swap or DataRole_swap command. But these commands are not supported by STUSB4500.

To send DR_Swap command, you need to use a USB PD solution which implement this optional command, like:

- STM32F0 + STUSB1602

- or STM32G0 + TCPP01