Browse Prior Art Database

Variable Shift Left for Signal Processor

IP.com Disclosure Number: IPCOM000059997D
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08

Publishing Venue

IBM

Related People

Authors:
Hoegh, BT Knudsen, NW McDonald, BS West, LP [+details]

Abstract

A Signal Processor has an instruction that allows the contents of an Internal Data Memory (IDM) location to be left shifted. The number of positions to shift must be a constant value. A method is described which allows the shift value to be variable. The conventional method is to use instructions that shift IDM left one position, and loop on these instructions the number of positions to shift left. The conventional method consumes too much processing time for many applications. Two methods are described to perform the variable count shift left operation. The methods require approximately the same processing power. The first method requires less program memory, but requires modifiable program memory to implement.