XRT94L33 Datasheet | Exar

DESCRIPTION The XRT94L33 is a highly integrated SONET/SDH terminator designed for E3/DS3/STS-1 mapping/de-mapping functions from either the STS-3 or STM-1 data stream. The XRT94L33 interfaces directly to the optical transceiver The XRT94L33 processes the section, line and path overhead in the SONET/SDH data stream and also performs ATM and PPP PHY-layer processing. The processing of path overhead bytes within the STS-1s or TUG-3s includes 64 bytes for storing the J1 bytes. Path overhead bytes can be accessed through the microprocessor interface or via serial interface. The XRT94L33 uses the internal E3/DS3 De Synchronizer circuit with an internal pointer leak algorithm for clock smoothing as well as to remove the jitter due to mapping and pointer movements. These De-Synchronizer circuits do not need any external clock reference for its operation. The SONET/SDH transmit blocks allow flexible insertion of TOH and POH bytes through both Hardware and Software. Individual POH bytes for the transmitted SONET/SDH signal are mapped either from the XRT94L33 memory map or from external interface. A1, A2 framing pattern, C1 byte and H1, H2 pointer byte are generated. The SONET/SDH receive blocks receive SONET STS-3 signal or SDH STM-1 signal and perform the necessary transport and path overhead processing. The XRT94L33 provides a line side APS (Automatic Protection Switching) interface by offering redundant receive serial interface to be switched at the frame boundary. The XRT94L33 provides 3 Mappers for performing STS-1/VC-3 to STS-1/DS3/E3 mapping function, one for each STS-1/DS3/E3 framers. A PRBS test pattern generation and detection is implemented to measure the bit-error performance. A general-purpose microprocessor interface is included for control, configuration and monitoring. APPLICATIONS - - - Network switches Add/Drop Multiplexer W-DCS Digital Cross Connect Systems FEATURES - Provides DS3/ E3 mapping/de-mapping for up to 3 tributaries through SONET STS-1 or SDH...