The VSC8114 is an ATM/SONET/SDH compatible transceiver integrating an on-chip Clock Multiplication Unit (PLL) for high speed clock generation as well as a Clock and data Recovery Unit (CRU) with 8-bit serialto-parallel and parallel-to-serial data conversion. The PLL clock is used for serialization in the transmit direction (Mux). The recovered clock is used for deserialization in the receive direction (Demux). The demultiplexer contains SONET/SDH frame detection and recovery. In addition, the device provides both facility and equipment loopback modes and a loop time mode. The part is packaged in a 100PQFP with an integrated heat spreader for optimum thermal performance and reduced cost. The VSC8114 provides an integrated solution for ATM physical layers and SONET/SDH systems applications.