International Business Machines Corporation

James R Robinson

Philip George Emma

Thomas R Puzak

Joshua W Knight

Michael Steven Siegel

Albert James Van Norstrand, Jr

Edward Hugh Welbon

Robert J Devins

Rudolph N Rechtschaffen

Robert Michael Dinkjian

Ralph James Williams

Benedicto U Messina

James Charles Gregerson

Donald W McCauley

A James Van Norstrand, Jr

Edward J D'Avignon

Ronald F Hill

Stephen J Nadas

Frederick O Flusche

Ethel L Richardson

Norman C Chou

Charles W Evans

Robert P Battaline

Joseph A Wetzel

James H Po Merene

Michael A Smoolca

Disclosed is a method of verifying the design of an integrated circuit chip comprised of one or more cores, comprising: creating a project core catalog comprising driver description files and application description files for each core; creating a system definition file for the integrated circuit chip; inputting the driver description files, the application description files and the system definition files into a code generator, the code generator outputting a test operating system test code; and applying the test operating system test code to a software simulation of the integrated circuit chip to perform design verification.

Automated system-on-chip integrated circuit design verification system

The detection and selection of the appropriate branch target address in a branch history table in super scalar microprocessor is simplified by reducing the complexity of the branch history table selection logic and providing a structure which is extendible to larger instruction fetch block sizes. This is accomplished by introducing a branch pattern field into the branch history table entry which indicates the presence of other branches (branches not defined by the current entry) within the instruction fetch block.

Branch history table with branch pattern field

Disclosed is a system and method of providing performance analysis on integrated circuit devices and systems using an IEEE JTAG 1149.1 interface. An integrated circuit device is described that includes an execution control register for receiving a control code from an external device via the JTAG interface, a means for selecting and coupling to one or more specific logic circuits on the device, one or more counters for recording specific events occurring on the logic circuits, and a counter register for managing the counter data and outputting it via the JTAG interface.

Performance monitoring through JTAG 1149.1 interface

A computer processing system includes a first memory that stores instructions belonging to a first instruction set architecture and a second memory that stores instructions belonging to a second instruction set architecture. An instruction buffer is coupled to the first and second memories, for storing instructions that are executed by a processor unit. The system operates in one of two modes. In a first mode, instructions are fetched from the first memory into the instruction buffer according to data stored in a first branch history table. In the second mode, instructions are fetched from the second memory into the instruction buffer according to data stored in a second branch history table. The first instruction set architecture may be system level instructions and the second instruction set architecture may be millicode instructions that, for example, define a complex system level instruction and/or emulate a third instruction set architecture.

Computer processing unit employing a separate millicode branch history

A method and system for controlling references to system storage. Milli-code mode provides a flexible technique for overriding storage controls associated with referencing system storage of a data processing system. The storage controls to be overridden are not replaced and therefore, a restore of the previous contents of those controls is not necessary. This allows for an increase in system performance and an increase in the efficiency and flexibility of the system. In addition to the above, a system request instruction is provided, which enables flexibility in the manner in which system requests are executed. The flexibility of the system request instruction reduces the number of instructions needed to perform system requests.

Method and system for controlling references to system storage by

A method and system for enhancing processing efficiency in a data processing system which includes multiple scalar instruction processors and a vector instruction processor. An ordered sequence of intermixed scalar and vector instructions is processed in a nonsequential order by coupling those instructions to selected processors. As each instruction is finished an indication of that state is stored within a finish instruction array. The first vector instruction within the ordered sequence is initiated within the vector instruction processor only after an indication that each scalar instruction preceding the first vector instruction is finished. A vector advance signal is generated by the vector instruction processor each time processing of a vector instruction is initiated. A subsequent vector instruction is then initiated when the vector processor assets are available only in response to the presence of the vector advance signal and an indication that all scalar instructions which proceed the subsequent vector instruction within the ordered sequence have finished, without encountering an exception. In this manner, chained processing of vector instructions may be accomplished by initiating processing of a subsequent vector instruction only after possible interruption by a scalar instruction exception is no longer possible.

Method and system for nonsequential execution of intermixed scalar and

A multi-prediction branch prediction mechanism predicts each conditional branch at least twice, first during the instruction-fetch phase of the pipeline and then again during the decode phase of the pipeline. The mechanism uses at least two different branch prediction mechanisms, each a separate and independent mechanism from the other. A set of rules are used to resolve those instances as to when the predictions differ.

Multi-prediction branch prediction mechanism

Inhibit means prevents a store-in-cache (SIC) from requesting or receiving any line fetch from MS when a clear line (CL) command is issued by a CPU to main storage (MS). Two CPU modes are provided: (1) an initial storage validation mode and (2) an instruction processing mode. The system operator controls the first mode so that a CPU can execute the CL command during system initialization without any prior data fetch from MS. In the second mode, the CL command is executed as a component of a program instruction fetched from MS that can clear a block in main storage. In a multiprocessor (MP), the CL command by any CPU requests a line store of pad data into an addressed line in MS only after each other SIC copy directory is searched and any found conflicting line is invalidated. Line castout to MS is prohibited for a conflicting line found in a cache by the CS command, which would have been a normal operation for other types of CPU commands. After any line conflict is found for any other cache in the MP, the completion of the CL command is delayed by cancelling the line pad write request to MS. Then the IE repeatedly reissues the CL command until all found conflicting lines are invalidated. As soon as no conflict is found in any copy directory, the currently issued CL command is completed by not cancelling the pad data request to MS, so that pad bytes are then written into the line in MS.

Store-in-cache processor means for clearing main storage

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Essex Junction, VT, United States of America

James R Robinson