Browse Prior Art Database

Dynamic Microcode Bit-Allocation for Microprocessors

IP.com Disclosure Number: IPCOM000064822D
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Isaac, GG Loffredo, JM [+details]

Abstract

A technique is described whereby a control latch is used in microprocessors to provide multiple use of microcode control points for bit-allocation functions. Typical microprocessors have an internal microcode, coded in multiple bit-words. Each microcode word is further subdivided into smaller groups, where each group controls a unique function within the microprocessor. It is not uncommon where every possible bit combination within a group is utilized so that additional control points are impossible to add for future expansion. As a result, the technique described herein provides a method to enable the microprocessor to be dynamically redefined. With the addition of a control latch, which is set and reset under microcode control, the control function of the microprocessor is expanded.