The FIMs (short for Flexible Interface Modules) are 8-bit controllers which are embedded in the Rabbit 6000 chip. The FIMs allow for additional peripheral support such as CANbus, SD/SDIO or even USB devices. Since FIMs are independent processors, this allows for a dedicated interface without adding further burden on the main processor. The RCM6700 has one FIM available, which is accessible through Port A and, depending on the protocol used, could use all eight pins.