APPLICATION NOTE 396

Design Migration from DS21Q55 to DS21Q50 or DS21Q59


Abstract: The DS21Q55 is a quad multichip module (MCM) device featuring independent transceivers that can be software configured for T1, E1, or J1 operation. Each is composed of a line interface unit (LIU), framer, HDLC controllers, and a TDM backplane interface, and is controlled via an 8-bit parallel port configured for Intel or Motorola bus operations. The DS21Q55 is software compatible with the DS2155 single transceiver and is pin compatible with the DS21Qx5y family of products. The DS21Q59 E1 quad transceiver contains all of the necessary functions for connection to four E1 lines. The DS21Q59 is a direct replacement for the DS21Q50 with the addition of signaling access and improved interrupt handling. Both are composed of a LIU, framer, and a TDM backplane interface, and are controlled via an 8-bit parallel port configured for Intel or Motorola bus operations or serial port operation.