The SP526 is a monolithic device that supports three (3) physical layer serial interface standards. The SP526 is fabricated using a low power BiCMOS process technology, and incorporates four (4) drivers and four (4) receivers can be configured via software for the selected interface modes at any time. The SP526 includes tri-state ability for the driver and receiver outputs through separate enable lines. A shutdown mode is also included through the mode select pins for power savings. When mated with the SP322 V.11/V.35 Programmable Transceiver, the SP526 provides the four (4) channels needed for handshaking/control lines such as CTS, RTS, etc. The two transceiver ICs are an ideal solution for WAN serial ports in networking equipment such as routers, DSU/CSU's, and other access devices.