The MC-ACT-TWSI is a "core" logic module specifically designed for Actel FPGAs that emulates the functionality of the industry standard two-wire serial interface, I2C. This core does not support 10-bit slave addressing or START byte data transfers. It facilitates upgrading current systems by allowing the designer to incorporate the TWSI function as well as other logic into a single, state of the art FPGA. This core is designed such that it can be instantiated into a Actel design and "hooked up" to I/O buffers and pads and then compiled to make a device that will "plug in" to a TWSI application. The core can be configured to operate as either a Master-Slave, MasterOnly, or Slave-Only.