The VSC8110 is an ATM/SONET/SDH compatible transceiver integrating high speed clock generation with 8 bit serial-to-parallel and parallel-to-serial data conversion. The high speed clock is generated using an on-chip PLL which is selectable for 155.52 or 622.08 Mhz operation. The part can be used with 19.44, 38.88, 51.84 or 77.76 Mhz external reference clocks. The demultiplexer contains SONET/SDH frame detection and recovery. In addition, the device provides both facility and equipment loopback modes. The part is packaged in a 100PQFP with integrated heat spreader for optimum thermal performance and reduced cost. The VSC8110 provides an integrated solution for ATM physical layers and SONET/SDH systems applications.