The Cypress Semiconductor CY7C955 is a Transceiver chip designed to carry ATM cells across SONET/SDH systems. On the transmit side, ATM cells coming from the Utopia interface are being mapped into SONET/SDH frames and then serialized for transmission over fiber or twisted pair (through an optical module or an equalizer chip). On the receive side, serial SONET/SDH datastreams coming from an optical module or an equalizer chip are being recovered by the intergrated clock and data recovery phase-locked loop, framed, processed, and presented as parallel ATM cells on the Receive Utopia Interface. The CY7C955 can be used in a Network Interface Card (NIC) design to connect the segmentation and Reassembly (SAR) chip to the optical modules or equalizer chip. The CY7C955 can also be used in work group or enterprise switches to connect the I/O FIFOs of the switch fabric to the optical module or equalizer in the interface boards.