Using I²C in EZ-USB® FX2LP™ to Interface with Peripherals Other Than the Boot EEPROM – KBA93230

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Question: Can you use I²C in EZ-USB® FX2LP™ to interface with peripherals other than the boot EEPROM (which stores the firmware)?



Yes. The EZ-USB I²C controller serves two purposes. First, it manages the serial EEPROM interface, which operates automatically at power on, to determine the enumeration method. Second, once the CPU is up and running, firmware can access the I²C controller for general-purpose use. This makes a wide range of standard I²C peripherals available to an EZ-USB-based system. Other I²C devices can be attached to the SCL and SDA lines as long as there is no address conflict with the serial EEPROM.

The A2, A1, and A0 pins of the boot EEPROM are connected to reflect 000 (for C0 load) or 001 (for C2 load). Any other combination of A2, A1, and A0 can be used for other I²C devices connected on the bus that need to be accessed by the firmware during device operation.