Hi,
We got some problems about using TUSB1310A PHY as a peripheral when it work with a USB DRD controller in device mode.
The D+ was not asserted high when we insert to the PC USB Host , even if we can detect that the VBUS PIN on the device was 5V， and PWRPRESET is assert high.
We connected the DWC_USB3 controller to the PHY with ULPI and PIPE interface, but actually the pipe interface was useless due to timing constraints and we do not need the SuperSpeed on our board, so we set the ISO_START to 1.
We also use the TUSB1310A PHY in the HOST Mode, we had worked well, Our Host system architecture flow the picture below.
we did not change any hardware in the controller and TUSB1310a PHY, we only change the connect VBUS pin to extra power supply because for peripheral mode.
we also change the Link controller peripheral mode by configure, Our Device system architecture just flow the picture below.
Flow the datasheet Power and reset release requirement，we confirm the ULPI_CLK is 60Mhz，
After the TUSB1310a is work up, we do this：
step1、 we use the device Link controller configure the TUSB1310a by ULPI interface;
step 2、we plus the peripheral into the host USB connect;
step 3、 we confirm the connect VBUS Pin is 5V, and the VBUS_IN for TUSB1310a is ≈0.5V, and the PWRPRESENT is change to High indicate the VBUS_IN is valid；
step 4、 The DP Pin not assert to 1 by T1310a， and the ULPI interface do not have any data transfer；
there is ULPI flow in the step1， The below as debug information.
We wonder know that：
What are the prerequisites for assert DP when usb controller is in peripheral mode ?
regards
Zhang
