International Business Machines Corporation

Victor N Kravets

Haoxing Ren

John A Darringer

George W Doerre

Ruchir Puri

Louise Helen Trevillyan

Smita Krishnaswamy

Zhuo Li

Charles Jay Alpert

Chin Ngai Sze

Mary Prilotski Kusko

Minsik Cho

Prabhakar Nandavar Kudva

Haifeng Qian

Ying Zhou

Hua Xiang

Matthew Mantell Ziegler

Eli Arbel

Jagannathan Narasimhan

Andrew James Sullivan

David John Geiger

Spencer K Millican

Dorothy Kucar

William E Dougherty

A system and method for using unreachable states of a circuit design in a testing mode to increase random testability of a random resistant logic circuit. Control-improving logic circuitry is integrated into a logic circuit design to improve its testability and will not affect behavior of the design in its functional mode (by remaining 'inactive' in the functional mode of the integrated circuit). The control-improving logic circuitry is automatically activated in testing mode. The control improving logic circuit is generated selectively for random resistant logic circuit regions that exhibit limited controllability in the functional mode and improves controllability of random resistant logic in the testing mode. The improved controllability results from activating test circuitry in the states that are not reachable during normal functionality. The utilization of unreachable states of a design renders unnecessary use of an explicit test enable signal, and provides for more compact implementation of test circuitry.

Synthesis for random testability using unreachable states in integrated circuits

Mechanisms are provided for generating a logic design of an integrated circuit device. An initial logic design representation of the integrated circuit device is received and one or more areas of the initial logic design representation are identified where logic elements in the one or more areas can be replaced with one or more multiplexer tree structures. Logic elements in the one or more areas of the initial logic design representation are replaced with multiplexer tree structures to generate a modified logic design representation. The modified logic design representation is output to a physical synthesis system to generate a physical layout of the integrated circuit device based on the modified logic design representation.

Routability using multiplexer structures

Two circuits, an original and a modified, are being recognized, with the original circuit having a first logic and the modified circuit having a second logic. The second logic contains at least one desired logic change relative to the first logic. An equivalence line is detected in the original circuit such that the first and second logic are equivalent from the circuit inputs to the equivalence line. At least one point of change is located amongst the logic gates that are neighboring the equivalence line. The points of change are accepted as verified if an observability condition is fulfilled. The observability condition is checked within a Boolean Satisfiability (SAT) formulation. Substitute logic for the verified points of change is derived using SAT and Boolean equation solving techniques, in such manner that the first logic becomes equivalent to the second logic.

Logic modification synthesis

Exemplary embodiments include a computer implemented method for large block and structured synthesis, the method including determining initial design data from starting points for a synthesis flow, receiving user-directed structuring is incorporated into the synthesis flow, applying logical synthesis on the initial design data, applying a physical design on the initial design data, determining whether circuit design parameters have been met and in response to circuit design parameters not being met, adjusting the circuit design parameters.

Converged large block and structured synthesis for high performance microprocessor designs

Disclosed is a method, system and computer program product to specify an integrated circuit. The integrated circuit includes a hardwired specific logic technology portion and a programmable specific logic technology portion. The method includes generating a hybrid logic network by mapping each uncertain logic function to an abstract programmable logic element implementation thereof and by mapping each known logic function to a technology-independent logic element implementation thereof; simplifying the hybrid logic network using logic synthesis optimizations; mapping the simplified hybrid logic network to a specific technology by mapping the abstract programmable logic element implementation to the specific programmable logic technology and the technology-independent logic element implementation to the specific logic technology; and further includes optimizing the mapped network to meet performance constraints. Generating involves using integrated circuit specification language extensions that include an Uncertain Function that is used in place of a logic function or operator, an Uncertain Function Assertion for imposing at least one constraint on the Uncertain Function, an Uncertain Register for a register having a programmable size within a specified range and an Uncertain Constant.

Method and system product for implementing uncertainty in integrated circuit designs with programmable logic

Routability (or wiring congestion) in a VLSI chip is becoming increasingly important as chip complexity increases. Congestion has a significant impact on performance, yield, and chip area. The present invention targets the optimization of congestion early in technology independent synthesis prior to physical design. Instead of attempting to optimize the logic structure as well as the spatial placement of a circuit, we pose a more modest goal limiting such optimization to the scope of logic synthesis. That is, we propose an aggressive optimization approach that is cognizant of circuit structure during technology independent synthesis and produces more predictable implementations which give better routability and yield.

Method for optimization of logic circuits for routability

Computer program product for implementing uncertainty in integrated circuit designs with programmable logic

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White Plains, NY, United States of America

Victor N Kravets