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High Speed Shift Mechanism

IP.com Disclosure Number: IPCOM000061225D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09

Publishing Venue

IBM

Related People

Authors:
Cannon, JW [+details]

Abstract

A barrel shifter is incorporated in a CPU as an inherent part of the ALU without affecting the cycle time of the machine. Fig. 1 is a simplified block diagram showing the possible locations that a barrel shifter would normally be incorporated into the data flow path associated with an ALU. As can be seen, all normally used locations require that the data flows through the ALU and the barrel shifter in a sequential fashion. This results in a longer total data path length and, consequentially, a longer machine cycle time. The barrel shifter, described here, performs its function without affecting the length of the total data path.