The DP83266 Media Access Controller and System Interface (MACSI) implements the ANSI X3T9 5 Standard Media Access Control (MAC) protocol for operation in an FDDI token ring and provides a comprehensive System Interface The MACSI device transmits receives repeats and strips tokens and frames It produces and consumes optimized data structures for efficient data transfer Full duplex architecture with through parity allows diagnostic transmission and self testing for error isolation and point-to-point connections The MACSI device includes the functionality of both the DP83261 BMACTM device and the DP83265 BSI-2TM device with additional enhancements for higher performance and reliability