View ds2152 datasheet:

DS2152 Enhanced T1 Single-Chip Transceiver www.dalsemi.com FEATURES PIN ASSIGNMENT Complete DS1/ISDN-PRI transceiver functionality Line interface can handle both long and short haul trunks 32-bit or 128-bit crystal-less jitter attenuator Generates DSX-1 and CSU line build outs Frames to D4, ESF, and SLC-96R formats Dual onboard two-frame elastic store slip buffers that can connect to asynchronous backplanes up to 8.192 MHz 8-bit parallel control port that can be used directly on either multiplexed or non-multiplexed buses (Intel or Motorola) Extracts and inserts robbed-bit signaling Detects and generates yellow (RAI) and blue (AIS) alarms Programmable output clocks for Fractional T1 Fully independent transmit and receive 1 functionality Integral HDLC con