An ANSI Standard ISDN Transceiver Digital Signal Processor

A United States standard for the ISDN U-Interface has been recently defined by the American National Standards Institute (ANSI). This standard specifies the 2B1Q line code, which is capable of higher performance levels than codes used in previous implementations. This paper describes the digital signal processing chip of a two-chip transceiver that fully conforms to the ANSI standard. A multiprocessor architecture is used, where each processor is optimized for the algorithm performed. The chip architecture, test features, design methodology, and layout considerations will be discussed.