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Cascode Current Switch ALU

IP.com Disclosure Number: IPCOM000066863D
Original Publication Date: 1979-May-01
Included in the Prior Art Database: 2005-Feb-20

Publishing Venue

IBM

Related People

Authors:
Underwood, JH [+details]

Abstract

Arithmetic logic unit (ALU) 10 (Fig. 1) is a multi-function generation macro circuit. It is configured in a bipolar cascode current switch arrangement. ALU 1 performs logical functions of AND, NAND, OR, NOR, XOR, EQUIVALENCE (XOR), BINARY FULL ADD, and BINARY FULL ADD by selectively steering the current through its different current paths in response to the input conditions at conditioning inguts AC, OC, carry-in inputs Cin, Cin and the data bit inputs A, A, B, B, Not shown are the emitter follower circuits for downshifting the input levels of B, B to B,' B' at terminals b, b. The output functions available at outputs X, Y in response to the input conditions at inputs AC, OC, Cin, Cin are shown in the following table: Because of its cascode configuration, circuit 10 minimizes power consumption and signal response delay.