The computer OS system must be able to connect as a USB endpoint to use the USB endpoint firmware update capability. Install a generic libusb-win32 USB device driver to connect to the USB endpoint of the TPS257xx-Q1 device. This connection can be accomplished by downloading a driver installation tool such as Zadig.

Complete the following after installing Zadig:

1. Connect Port A of the device to be programmed to a PC. Make sure the TVSP pin is configured for FWUP mode.
2. Download then run the Zadig executable, then choose the libusb-win32 option (see Figure 5-10).
   Figure 5-10 Zadig USB Driver Installer Dialog Window

Once enumerated correctly, the device end-point enumerates in the device manager as Figure 5-11 shows.

Some PC systems operate with the WINUSB vs LIBUSB driver. If the LIBUSB error is received upon USB EP firmware update connection, update the PC driver with the WINUSB driver, then reboot the computer system. The WINUSB driver can be installed with the Zadig tool by choosing the winusb option instead of libusb.