External pull-up for FX1/FX2LP

Question: When the FX1 is operated from 3.3V Vcc, can an output port be pulled to +5V using an external pullup?



Yes, the output port can be pulled to +5V using an external pullup. For this, you need to configure your EZ-USB I/O pins as open-collector outputs with pullup resistors to 5V. To make a pin act as an open-collector output, set the appropriate OUTx bit to 0, then toggle the corresponding OEx bit to switch the pin between low (output) and high-impedance (input) states.