The SP509 is a monolithic device that supports eight (8) popular serial interface standards for Wide Area Network (WAN) connectivity. The SP509 is fabricated using a low power BiCMOS process technology, and incorporates a Sipex regulated charge pump allowing +5V only operation. Sipex's patented charge pump provides a regulated output of +5.8V, which will provide enough voltage for compliant operation in all modes. Eight (8) drivers and eight (8) receivers can be configured via software for any of the above interface modes at any time. The SP509 requires no additional external components for compliant operation for all of the eight (8) modes of operation other than four capacitors used for the internal charge pump. All necessary termination is integrated within the SP509 and is switchable when V.35 drivers and V.35 receivers, or when V.11 receivers are used. The SP509 provides the controls and transceiver availability for operating as either a DTE or DCE. Additional features with the SP509 include internal loopback that can be initiated in any of the operating modes by use of the LOOPBACK pin. While in loopback mode, receiver outputs are internally connected to driver inputs creating an internal signal path bypassing the serial communications controller for diagnostic testing. The SP509 also includes a latch enable pin with the driver and receiver address decoder. The internal V.11 or V.35 receiver termination can be switched off using a control pin (TERM_OFF) for monitoring applications. All eight (8) drivers and receivers in the SP509 include separate enable pins for added convenience. The SP509 is ideal for WAN serial ports in networking equipment such as routers, concentrators, network muxes, DSU/CSU's, networking test equipment, and other access devices. Applicable U.S. Patents-5,306,954; and others patents pending Date: 8/19/04