International Business Machines Corporation

Robert J Shadowen

Wolfgang Roesner

Derek E Williams

Ali S El-Zein

Viresh Paruthi

Kevin Franklin Reick

Samuel I Ward

Thomas Edward Rosser

Alvan Wing Ng

Bryan Ronald Hunt

Bryan J Robbins

Luis Alfonso Lastras-Montano

Stephen Gerard Shuma

Barry Marshall Trager

Alexey Y Lvov

Shmuel Winograd

Stephen J Barnfield

Clay Chip Smith

Gradus (Geert) Janssen

Based on a directive in a control file, a processor pre-routes, within a hierarchical integrated circuit design, a signal through one or more levels of design hierarchy between a signal source at a higher level of the design hierarchy and an entity instance at a lower level of the design hierarchy. The processor processes entity instances in the design hierarchy in a bottom-up manner to insert technology-specific structures into the hierarchical integrated circuit design. During the processing, the processor inserts into a particular entity instance of the design hierarchy a technology-specific structure and connects the technology-specific structure to the signal pre-routed to the particular entity instance by the pre-routing.

Signal pre-routing in an integrated circuit design

Method and apparatus for managing connections within a netlist include using a clone module to the connections between different components within the netlist. A buffer may be inserted between components of a netlist to split a connection into multiple segments and then moved into an associated first instance. The inclusion of the buffer allows for one or more of pin cloning and subway utilization to occur when mapping between a functional hierarchy to a physical hierarchy is performed.

Pin cloning and subway creation on automatically generated design physical hierarchy

In one exemplary embodiment of the invention, a method includes: receiving a first description for a circuit whose operation over a plurality of inputs is to be verified; receiving a second description for expected behavior of the circuit, where the expected behavior in the second description is expressed as a set of algebraic systems of multivariable polynomials over at least one Galois field; applying at least one computational algebraic geometry technique to a combination of the first description and the second description to determine whether the circuit is verified, where verification of the circuit confirms that at least one output obtained based on the first description corresponds to at least one expected value based on the expected behavior expressed in the second description; and outputting an indication as to whether the circuit is verified.

Circuit verification using computational algebraic geometry

One or more hardware description language (HDL) files describe a plurality of hierarchically arranged design entities defining a digital design to be simulated and a plurality of configuration entities not belonging to the digital design that logically control settings of a plurality of configuration latches in the digital design. The HDL file(s) are compiled to obtain a simulation executable model of the digital design and an associated configuration database. The compiling includes parsing a configuration statement that specifies an association between an instance of a configuration entity and a specified configuration latch, determining whether or not the specified configuration latch is described in the HDL file(s), and if not, creating an indication in the configuration database that the instance of the configuration latch had a specified association to a configuration latch to which it failed to bind.

Model build in the presence of a non-binding reference

A logic design and synthesis program, method and system provides intelligibility and independence of separate blocks in digital logic designs at the synthesis level. The sequential and combinational logic are separated and the sequential logic is then mapped to flip-flop library components. State-retaining elements, i.e., flip-flops detected in the input hardware description language (HDL) are represented in the sequential logic HDL output. The combinational logic HDL and the sequential logic HDL are connected only by signals, so signals are introduced to represent the flip-flop signals and variables detected in the input HDL. The sequential and combinational logic HDL are then synthesized to produce the design.

Abstraction level-preserving conversion of flip-flop-inferred hardware description language (HDL) to instantiated HDL

A method comprises generating a first behavioral model of a circuit describing a physical circuit in a first configuration. The first configuration comprises a first master latch, a first fanout path, and a logic cone. The first master latch couples to the first fanout path and is configured to receive a first data input signal. The first fanout path comprises a plurality of output sinks, each coupled to the logic cone. The first behavioral model is modified to generate a second behavioral model describing the physical circuit in a second configuration. The second configuration comprises an error circuit and an abstract latch clone based on the first master latch. A configuration file is generated based on the second behavioral model. The configuration file comprises information representing a plurality of instantiated latch clones based on the abstract latch clone, each configured to couple to the first data input signal and to one or more output sinks of the plurality of output sinks. The second behavioral model and the configuration file are together configured for input to a synthesis tool.

Circuit design optimization

A method includes generating a first behavioral model of a circuit, the first behavioral model describing a physical circuit in a first configuration. The first configuration comprises a first logic structure configured to generate a first intermediate signal based on a received first plurality of inputs. The first configuration further comprises a logic cone configured to generate a scan output based on the first intermediate signal and a plurality of scan inputs. The first behavioral model is modified to generate a second behavioral model describing the physical circuit in a second configuration. The second configuration comprises an error circuit configured to receive the scan output and the first intermediate signal. A testability model is generated based on the second behavioral model, the testability model comprising a first structural representation of the first logic structure. In the event the first logic structure causes a coverage problem, the testability model is modified to include an inversion structure. The inversion structure is configured based on the first logic structure. The inversion structure is configured to generate an inversion structure output. The testability model is modified to couple the inversion structure output as an input to the error circuit.

In a method of data processing, a database defines a Dial entity and at least one instance of the Dial entity. Each instance of the Dial entity has an input having a plurality of different possible input values and one or more outputs, and each of the plurality of different possible input values has a different associated output value set for the one or more outputs. Each instance of the Dial entity determines a value of at least one of a plurality of configuration latches in a digital system separate from the database. The database also associates with the Dial entity at least one set of biasing weights that, when applied, determines a probability of each instance of the Dial entity having particular ones of the plurality of different possible input values. In response to a call to set the plurality of configuration latches, the database is accessed to apply the at least one set of biasing weights to select one of the plurality of different possible input values for the at least one instance of the Dial entity. The plurality of configuration latches in the digital system are set based upon the output value set for the one or more outputs of the at least one instance of the Dial entity.

Specifying a configuration for a digital system utilizing dial biasing weights

A digital system includes one or more design entities containing a functional portion of the digital system. Within a configuration database, one or more configuration entities are instantiated. The configuration entities including an Error checking Dial (EDial) having a plurality of input latches within the digital design and a plurality of output latches within the digital design. The EDial has an associated function defining a relationship between values of the input latches and values of the output latches. An instance of the EDial in the configuration database is accessed to access the values of the output latches in the digital design.

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Austin, TX, United States of America

Robert J Shadowen