Three input arithmetic logic unit with barrel rotator

US6116768A · kind A · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Karl M. Guttag · Plano, US
• Keith Balmer · Bedford, GB
• Robert J. Gove · Plano, US
• Christopher Jensen Read · San Diego, US
• Jeremiah E. Golston · Sugar Land, US
• Sydney W. Poland · Katy, US
• Nicholas Ing-Simmons · Huntingdon, US
• Phillip Moyse · Bromham, GB

Key dates

• Filing date: Nov 30, 1993
• Grant date: Sep 12, 2000
• Expiry date: Nov 30, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F12/0284
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A data processing apparatus includes a three input arithmetic logic unit (230) that generates a combination of the three inputs that is selected by a function signal. Data registers (200) store the three data inputs and the arithmetic logic unit output. The second input signal comes from a controllable barrel rotator (235). The rotate amount is a default rotate amount stored in a special data register, a predetermined set of bits of data recalled from a data register or zero. A one's constant source (236) is connected to the barrel rotator (235) to supply a multibit digital signal of "1". This permits generating a second input signal of the form 2.sup.N, with N being the rotate amount. The output of the barrel rotator (235) may be stored independently of the arithmetic logic unit (230) result. In the preferred embodiment of this invention, the three input arithmetic logic unit (230) is embodied in a data processor circuits as a part of a multiprocessor integrated circuit (100) used in image processing.