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Flexibility Enhancement to Microcode Branching in a Control Store Processor

IP.com Disclosure Number: IPCOM000082509D
Original Publication Date: 1974-Dec-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Evans, CW: AUTHOR

Abstract

A limitation in flexibility of control store processors is the unforeseen need for a new branch order, based on a logical combination of transient conditions within the machine. Performing the tests serially with a group of existing microorders often is fruitless, since the conditions may change while the tests are being made.

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Flexibility Enhancement to Microcode Branching in a Control Store Processor

A limitation in flexibility of control store processors is the unforeseen need for a new branch order, based on a logical combination of transient conditions within the machine. Performing the tests serially with a group of existing microorders often is fruitless, since the conditions may change while the tests are being made.

As a first solution to this problem, microorders may be included in the original machine which captures, on command, every transient data path condition of cycle n. Companion orders would also be included which test the captured condition on cycle n+1 or later. Thus, a complex branch test could be constructed over several cycles, all relating to conditions of cycle n.

A second solution is to provide a microorder which stops the processor clock, with the exception of the control store mechanism. The control program could then proceed to test the halted processor. Several simple branch tests may be used to accomplish the complex branch order needed. A command from the control store then resumes the execution. Clock Start/Stop is also a potentially useful microdiagnostic tool.

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