TP3420A ISDN S/T Interface DeviceGeneral Des criptionThe TP3420A is an enhanced version of the TP3420, with anumber of upgraded features for compliance with the newrelease of ANSI T1.605-1991 and CCITT I-430. At initialpower-up the device is fully backwards compatible with theTP3420 device, and modifications to the firmware are onlyrequired to take advantage of the new features.The TP3420A S Interface Device (SID™) is a completemonolithic transceiver for data transmission on twisted pairsubscriber loops. It is built on National’s advanced 1.0 microndouble-metal CMOS process, and requires only asingle +5V supply. All functions specified in CCITT recommendationI.430 (1991) and ANSI T1.605 (1991) for ISDNbasic access at the “S” and “T” interfaces are provided, andthe device can be configured to operate either in a TE (TerminalEquipment), in an NT-1 or NT-2 (Network Termination)or as a PABX line-card or trunk-card device.As specified in I.430, full-duplex transmission at 192 kb/s isprovided on separate transmit and receive twisted wire pairsusing inverted Alternate Mark Inversion (AMI) line coding. 2“B” channels, each of 64 kb/s, and 1 “D” channel at 16 kb/sare available for users’ data. In addition, the TP3420A providesthe 800 b/s “S1”, “S2” & “Q” multiframe channels forLayer 1 maintenance.All I.430 wiring configurations are supported by the TP3420ASID, including the “passive bus” for up to 8 TE’s distributedwithin 200 meters of low capacitance cable, andpoint-to-point and point-to-star connections up to at least1500 meters (24AWG). Adaptive receive signal processingensures low bit error rates on any of the standard types ofcable pairs commonly found in premise wiring installationswhen tested with the noise sources specified in I.430.Featuresn 2 B + D 4-wire 192 kb/s transceivern Selectable TE or NT moden Exceeds I.430 range: 1.5 km point-to-pointn Adaptive receiver for high noise immunityn Adaptive and fixed timing options for NT-1n Clock resynchronizer and elastic buffers for NT-2/LTn Slave-slave mode for NT-2 trunksn Extensive hardware support for SC1, SC2 and Qchannel messagingn Bipolar violation detection and FECV messagingn Selectable system interface formatsn MICROWIRE™ and SCP compatible serial controlinterfacen TP3054/7 Codec/Filter COMBO™ compatibilityn Single +5V supplyn 20-pin package DIP, PLCCApplicationsn Same Device for NT, TE and PBX Line Cardn Point-to-Point Range Extended to 1.5 kmn Point-to-Multipoint for all I.430 Configurationsn Easy Interface tLAPD Processor MC68302, HPC16400Terminal Adapter MC68302, HPC16400Codec/Filter COMBO TP3054/7 and TP3076“U” Interface Device TP3410Line Card Backplanes—No External PLL Neededn Line Monitor Mode for Test Equipment