The DS2154 Enhanced Single-Chip Transceiver (ESCT) contains all of the necessary functions for connection to E1 lines. The device is an upward compatible version of the DS2153 Single-Chip Transceiver. The onboard clock/data recovery circuitry coverts the AMI/HDB3 E1 waveforms to a NRZ serial stream. The DS2154 automatically adjusts to E1 22AWG (0.6 mm) twisted-pair cables from 0 to over 2 km in length. The device can generate the necessary G.703 waveshapes for both 75-ohm coax and 120-ohm twisted cables. The onboard jitter attenuator (selectable to either 32 bits or 128 bits) can be placed in either the transmit or receive data paths. The framer locates the frame and multiframe boundaries and monitors the data stream for alarms. It is also used for extracting and inserting signaling data, Si, and Sa bit information. The device contains a set of internal registers which the user can access to control the operation of the unit. Quick access via the parallel control port allows a single controller to handle many E1 lines. The device fully meets all of the latest E1 specifications including ITU G.703, G.704, G.706, G.823, G.932, and I.431 as well as ETS 300 011, 300 233, 300 166, TBR 12 and TBR 13. 1 of 87