TUSB212-Q1: How to into the HS mode in the device Mode Testing?

Hi AE,

         Add question.

         About the device mode testing, after connected the device, the PC host can start enumeration and sent the packets to device.

        1. Does the PC Host need to send any specific command to the Device for it to switch to HS mode?

 Best Regards

Hi Bruce,

Bruce Dai said:

In the four step, when I connected the device to TUSB212 output, but the ENA_HS is always Low.

         1. Do you have any suggestions for recovery in this situation? 

How is the TUSB212 being powered? Are you using an EVM? For device mode testing, the TUSB212 needs to be powered by an external power rail and not VBUS, as using VBUS will cause the TUSB212 to not be enabled in time.

Additionally, the TUSB212 needs to be enabled before any data is sent through the USB2 lines. If the TUSB212 is enabled afterwards, it will not see the USB2 handshake, and will fail to enable.

Could you send the device schematic and a block diagram for reference?

Bruce Dai said:

2. Why set an init position and a test position on the Relay board?

This depends on the test fixture being used. Some boards come with a INIT and TEST switch, which needs to be used to have the correct terminations on the USB2 lines. Not every test fixture has this.

Bruce Dai said:

1. Does the PC Host need to send any specific command to the Device for it to switch to HS mode?

Once the TUSB212 is powered, and there is no data being sent on the USB2 lines, HSETT should be used to send the TEST_PACKET command through the corresponding USB2 port. After doing this, the redriver should enable and it should be boosting.

Thanks,

Ryan