International Business Machines Corporation

Robert Glen Gerowitz

Joseph Andrew Iadanza

Chad Everett Winemiller

Sarah B Higgins

Michael Patrick Muhlada

Claudia M Tartevet

Kenichi Tsuchiya

Zhibin Cheng

John William Marshall

Carl Thomas Gray

Raymond Paul Rizzo

Bryan Keith Bullis

Christopher G Riedle

William Arthur Noon

Jeffrey Paul Boettler

R Thomas Cruz

Carisa Anne Cassani

Kenneth Patrick Zabrycki

Benjamin Edward Floering

Howard James Schubert, Jr

Approaches for testing phase rotators are provided. A circuit for testing phase rotators includes a compare element including a first input and a second input, wherein the compare element is configured to compare a first phase of a first signal provided at the first input to a second phase of a second signal provided at the second input. The circuit also includes a first test bus connected to the first input and a second test bus connected to the second input.

Testing integrated circuit designs containing multiple phase rotators

Illustrative embodiments provide a computer-implemented method for resolving indeterminate states by inserting logic into a design. The computer-implemented method receives an original design input from a requester to form a received input and determines whether the received input contains an indeterminate output. Responsive to a determination that the received input contains an indeterminate output, the computer-implemented method generates a temporary design from the received input, wherein the temporary design contains 'unique' output and all inputs, updates the temporary design, and synthesizes the original design and each temporary design individually to form a synthesized original design and a set of synthesized temporary designs. The computer-implemented method merges the synthesized original design with the set of synthesized temporary design to form a final design; and returns the final design to the requester.

Indeterminate state logic insertion

The invention is directed to validating a specified manufacturing test rule, which pertains to an electronic component. The method includes generating a file of test data sets, wherein each test data set in the file is valid for the rule. Each test data set includes a stimulus comprising one or more single input vectors, and further includes a set of results that are expected. The method further comprises constructing a testbench to prepare testcases for simulation, wherein each testcase corresponds to the stimulus and the expected output results of one of the test data sets, and each testcase is disposed to be simulated separately, or independently, from every other testcase. The method further comprises selectively preparing each of the testcases for simulation, in order to provide simulated results for the stimulus corresponding to each testcase. The expected results and the simulated results are compared for each testcase.

Validating manufacturing test rules pertaining to an electronic component

A system for creating manufacturing test rules. Stimuli for an electronic design are generated automatically by a stimuli generator. The stimuli generator takes into account certain limitations of the design when automatically generating the manufacturing test rules. The design is tested by a testbench using the stimuli. A simulation log for the design is generated by the testbench. The simulation log is then processed by a simulation log processor. An HDL representation of the design is generated by the simulation log processor using the processed simulation log. A gate-level version of the design is generated by a synthesis tool using the HDL representation of the design. The gate-level version of the design is further processed by the synthesis tool to make any necessary modifications. Then, the gate-level version of the design is outputted as the final manufacturing test rule. Thus, creating manufacturing test rules can be completely automated.

Automatically creating manufacturing test rules pertaining to an electronic component

A system for at-functional-clock-speed continuous scan array built-in self testing (ABIST) of multiport memory is disclosed. During ABIST testing, functional addressing latches from a first port are used as shadow latches for a second port's addressing latches. The arrangement reduces the amount of test-only hardware on a chip and reduces the need to write complex testing software. Higher level functions may be inserted between the shadow latches and the addressing latches to automatically provide functions such as inversions.

Scanned memory testing of multi-port memory arrays

A circuit for a multiplexer includes a pair of NAND gates with outputs coupled to an OAI gate constructed from a complementary circuit formed from solid state devices. A current flow controller formed from solid state devices is coupled to one of the NAND gates. When activated the controller inhibits the flow of current through the NAND gate and a portion of the OAI gate to which the controller is connected. As a consequence, leakage power is not consumed within the multiplexer. Several of the applications in which the circuit is used are also demonstrated in the specification.

Multiplexor with leakage power regulator

A method of preventing current leakage in logic circuits within level sensitive scan design (LSSD) latch circuits in an application specific integrated circuit (ASIC). When the ASIC is in a manufacturing test mode, a gating signal at an input terminal of a power gating circuit is set to exceed a threshold voltage of transistors within the power gating circuit. The gating signal thus causes the power gating circuit to enable electrical current to reach the LSSD latch circuits. When the ASIC is in a normal functional mode, the gating signal is set below the threshold voltage. The gating signal thus causes the power gating circuit to prevent electrical current from reaching particular logic circuits (e.g., scan logic) within the LSSD latch circuits, thereby conserving power within the ASIC by preventing current leakage and heat generation in the LSSD latch circuit.

Method and system for low-power level-sensitive scan design latch with power-gated logic

An improved method and process is provided for verifying a digital logic design complies with certain manufacturing test rules or guidelines. A replacement is created for any portion of a design to make it usable by the manufacturing test tool set, without requiring the contents of that portion of the design to be implemented. The inputs and outputs of a portion of the design are examined for violations of the manufacturing test rules or guidelines. If there are no violations, the contents of this portion of the design are replaced with some basic contents which satisfy the manufacturing structure rules. The interconnections between logic blocks can then be tested using test generation tools to ensure the design does not violate manufacturing test rules or guidelines The compliance verification can thus be done much earlier in the design process than typically occurs.

Method and apparatus for manufacturing test generation

Scan chains are designed for an IC based on test coverage for functional logic units, Before physical placement the scan circuit elements are assigned scan attributes which define which scan circuit elements must remain coupled and also defines which groups of scan circuit elements must remain in selected groups. The scan chains and the logic are physically placed and location data on the scan circuit elements are determined from the placement data. Using the scan attributes, single scan circuit elements and scan circuit elements that must remain connected (sub-scan chains) are re-allocated across a same number of new scan chains. These scan circuit elements are rewired using an algorithm that minimizes scan path lengths within the new scan chains.

Scan chain connectivity

Descriptive statements representative of a communication level coupling the functional logic of an integrated circuit to the external environment is translated into complex functional specification language for input to hardware design programs. Plain language within the functional specifications is converted to proper design language to implement hardware described by the functional specification.

Hardware design language generation for input/output logic level

Stuck-at fault, shorted and open circuit conditions occurring in the differential inputs to Differential Receivers on a Large Scale Integrated (LSI) chip are detected by a test circuit arrangement fabricated on the chip. The test circuit arrangement includes Pass Gate devices operatively coupled to the differential inputs and an Exclusive NOR circuit (XNOR) coupled to the Pass Gate devices. Pull devices are coupled to the Pass Gate devices and the differential inputs. By activating the Pass Gate devices and applying a test sequence to the differential inputs, the state of the output of the XNOR circuit indicates if an open circuit, stuck-at or short exists in the inputs to the Differential Receiver.

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Raleigh, NC, United States of America

Robert Glen Gerowitz