International Business Machines Corporation

Kai Oliver Weber

Christian Jacobi

Viresh Paruthi

Jason Raymond Baumgartner

Geert Janssen

Stefan Letz

Juergen Vielfort

Chung-Lung K Shum

Wolfgang Gellerich

Martin Schwidefsky

Jiazhao Xu

Matthias Pflanz

Udo Krautz

Timothy John Slegel

Christopher A Krygowski

Nicolas Maeding

Tobias Gemmeke

Michael P Mullen

Klaus Keuerleber

Michelangelo Masini

Nico Gulden

Jens Dittrich

Stefan Schuh

A data processor comprising a plurality of registers, and instruction execution circuitry having an associated instruction set, wherein the instruction set includes an instruction specifying at least a mask operand, a register operand and an immediate value operand, and the instruction execution circuitry, in response to an instance of the instruction, determines a Boolean value based on the mask operand and sets a respective one of a plurality of registers specified by the register operand of the instance to a value of the immediate value operand if the Boolean value is true. The instruction execution circuitry, in response to the instance of the instruction, may set the respective one of the plurality of registers specified by the register operand of the instance to zero if the Boolean value is false.

Load register on condition immediate instruction

Load register on condition immediate or immediate instruction

A data processing system including multiple processors with a hierarchical cache structure comprising multiple levels of cache between the processors and a main memory, wherein at least one page mover is positioned closer to the main memory and is connected to the cache memories of the at least one shared cache level (LLL), the main memory and to the multiple processors to move data between the cache memories of the at least one shared cache level, the main memory and the processors. In response to a request from one of the processors, the at least one page mover fetches data of a storage area line-wise from at least one of the following memories: the cache memories and the main memory maintaining multiple processor cache memory access coherency.

Data processing in a multiple processor system to maintain multiple processor cache memory access coherency

Load register on condition with zero or immediate instruction

A verification method is provided and includes randomly choosing a hardware executed instruction in a predefined program to force Opcode Compare on, determining an identity of a corresponding opcode from the chosen instruction and initializing Opcode Compare logic to trap the chosen instruction to firmware and creating firmware to initiate performance of hardware verification in the firmware and re-initiating performance of the hardware verification in hardware.

Firmware and hardware verification using Opcode comparison

An improved method of verifying a processor design using a processor simulation model in a simulation environment is disclosed, wherein the processor simulation model includes at least one execution unit for executing at least one instruction of a test file. The method includes tracking each execution of each of the at least one instruction, monitoring relevant signals in each simulation cycle, maintaining information about the execution of the at least one instruction, wherein the maintained information includes a determination of an execution length of a completely executed instruction, matching the maintained information about the completely executed instruction against a set of trap elements provided by the user through a trap file, and collecting the maintained information about the completely executed instruction in a monitor file in response to a match found between the maintained information and at least one of the trap elements.

Verifying a processor design using a processor simulation model

A mechanism is provided for verifying a register-transfer level design of an execution unit. A set of instruction records associated with a test case are generated and stored in a buffer. For each instruction record in the set of instruction records associated with the test case: the instruction record is retrieved from the buffer and sent to both a reference model and an execution unit in the data processing system. Separately, the reference model and the execution unit execute the instruction record and send results of the execution of the instruction record to a result checker in the data processing system. The result checker compares the two results and, responsive to a mismatch in the results, a failure of the test case is indicted, the verification of the test case is stopped, and all data associated with the test case is output from the buffer for analysis.

Verifying a register-transfer level design of an execution unit

An improved method, system and computer-readable medium for constructing binary decision diagrams for a netlist graph is disclosed. The method comprises traversing a netlist graph in a depth-first manner. At least one binary decision diagram is built for one input of a node of the netlist graph using a binary decision diagram for the other input of that node as a don't-care condition.

Method and system for building binary decision diagrams optimally for nodes in a netlist graph using don't-caring

A new and convenient methodology for proving the correctness of multiplier and multiply-accumulate circuit designs in a full custom design flow. Such an approach utilizes a basic description of the implemented algorithm, which is created in early phases of the design flow and requires only little extra work for the designer who spends most of the time in full-custom optimizations. Such an approach also defines arithmetic circuit at the arithmetic bit level and allows for the generation of a gate level netlist. Given a structural similarity between the specification and design under verification, a large amount of structural similarity between the generated netlists is obtained so that a standard equivalence checker can be utilized to verify the design against the specification.

Method and system for formal verification of an electronic circuit design

A method of generating a test case from a given test case structure, the method including generating instructions for the given test case structure, propagating predefined results in a backwards manner, randomly generating remaining operands of the test case structure in a forwards manner, and calculating a result for the test case by determining missing input operands and storing these input operands in both the temporary register file and the initial register file, and calculating missing results and storing all results in the temporary register file.

Test case generation with backward propagation of predefined results and operand dependencies

A method, system and computer program product for building decision diagrams efficiently in a structural network representation of a digital circuit using a dynamic resource constrained and interleaved depth-first-search and modified breadth-first-search schedule is disclosed. The method includes setting a first size limit for a first set of one or more m-ary decision representations describing a logic function and setting a second size limit for a second set of one or more m-ary decision representations describing a logic function. The first set of m-ary decision representations of the logic function is then built with one of the set of a depth-first technique or a breadth-first technique until the first size limit is reached, and a second set of m-ary decision representations of the logic function is built with the other technique until the second size limit is reached. In response to determining that a union of first set and the second set of m-ary decision representations do not describe the logic function, the first and second size limits are increased, and the steps of building the first and second set are repeated. In response to determining that the union of the first set of m-ary decision representations and the second set of m-ary decision representations describe the logic function, the union is reported.

System for building binary decision diagrams efficiently in a structural network representation of a digital circuit

Building binary decision diagrams efficiently in a structural network representation of a digital circuit

A method of verifying a digital design is disclosed. The method comprises generating a reference model for a first digital design and creating an operational model for a second digital design, wherein the first digital design and the second digital design are intended to have a same logical function. A plurality of testcase types are then created by constraining one or more internal signals, and one or more test scripts representing the plurality of testcase types are produced. The method also includes verifying the second digital design with a testing simulation program by comparing results of the test scripts from the operational model and the reference model.

System for verification of digital designs using case-splitting via constrained internal signals

A method for performing equivalence checking on logic circuit designs is disclosed. Within a composite netlist of an original version and a modified version of a logic circuit design, all level-sensitive sequential elements sensitized by a clock=0 are converted into buffers, and all level-sensitive sequential elements sensitized by a clock=1 are converted into level-sensitive registers. A subset of edge-sensitive sequential elements are selectively transformed into level-sensitive sequential elements by removing edge detection logic from the subset of the edge-sensitive sequential elements. A clock to the resulting sequential elements is then set to a logical '1' to verify the sequential equivalence of the transformed netlist.

Growing community of inventors

Stuttgart, Germany

Kai Oliver Weber