EZ-USB™ HX2VL: Need pull-up resistors to connect TEST/I2C_SCL pin? (KA-03325)
No, you do not need pull-up resistors to connect the TEST/I2C_SCL pin. TEST/I2C_SCL is a multipurpose pin. If this pin has a pull-up resistor, HX2VL enters TEST mode after RESET is de-asserted (from RESET=0 to RESET=1). HX2VL controls the TEST/I2C and SDA pins to ensure that the I2C protocol spec is followed.
Infineon recommends that you connect the TEST/I2C_SCL pin to the SCL of another IC on the schematic, without the pull-up resistor. HX2VL DVK designs that do not use pull-up resistors have been tested and verified.