A rate adaption coprocessor for terminal adapters and U-interface modems

A multistandard rate adapter coprocessor chip, designed for use in ISDN terminal adapters and U-interface modems, is presented. It provides a compact, low-power protocol converter to connect asynchronous (up to 19200 b/s) and synchronous (up to 64 kb/s) data terminal equipment with any digital 64-kb/s network. The multistandard rate adapter chip was developed in a 2- mu m CMOS technology using a hierarchical design methodology. The rate adapter is the cornerstone of a 144-kb/s U-interface modem and a major breakthrough for the next-generation multistandard terminal adapter.<
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