TANII

Thank you for the reply and clear answer. I got it. TANII

Hello! Recently, I purchased a Cora Z7-10 board and tried to implement the baremetal USB-CDC (USB 2.0) design found in the following Xilinx website: Zynq-7000 AP SoC USB CDC Device Class Design Example Techtip https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18841624/Zynq-7000+AP+SoC+USB+CDC+Device+Class+Design+Example+Techtip I know that Digilent guarantees that the USB Type-A connector on the Cora board acts not as a USB device but as a USB host, as indicated in the reference website for the Cora board. However, when I implemented the above design in my Cora board, it seems that it works as a USB device (Do you believe this?), since the Zynq communicates with a COM port of windows10 via a USB cable connected with the USB Type-A connector on the Cora board (I think that windows can only act as the USB host). So, now I am considering to use the USB Type-A connector to establish the second UART connection with windows 10, because this is so useful that we can establish two parallel connections with windows 10 using the simple UART protocol (one can be used for slow transaction via the FTDI chip (115200 bau), and the other can be used for comparatively fast transaction (approximately 40 Mbps) via the Microchip USB3320 USB 2.0 Transceiver Chip). What I am afraid of is that it may damage to the board if I continue to use the connector as a USB device, as I conjecture that the reason that the use of the connector is limited to the USB host is because of the wiring condition of the USB3320 chip, which could be fixed to the USB host mode. Are there any available reference (e.g. circuit diagram) on the wiring condition of the USB3320 chip of the Cora board? I guess, I can figure out what happens if I continue to use it as a USB device and the reason why it also works as the USB device, if I got such documents. Thanks in advance, TANII