An evolutionary VLSI chip set for ISDN

The authors describe a cost-effective and flexible approach to introducing the ISDN (integrated-services digital network) into System 12 with respect to CMOS and nMOS integrated circuits. The chip set includes three transmission devices for basic or primary rate access: a two-wire U-interface transceiver using the 4B3T line code, a four-wire transceiver and the PRA trunk logical interface. The layer 2 function is covered by a device including functions for link layer protocols on the D-channel or on the B-channel for both LAPD and CCITT No.7 signaling schemes. An on board controller interface provides the control and transmission interface between the line modules and the switching network. The set is completed with a multistandard rate adapter for terminal adapter application.<>