International Business Machines Corporation

Richard J Grupp

Mark R Taylor

Kelly A Ockunzzi

Steven Frederick Oakland

Roderick Michael West

Kathryn E Rickard

Craig M Monroe

Yelena M Tsyrkina

Gary L Kunselman

Raymond W Schuppe

Novel structures and testing methods for the FPGAs (Field-Programmable Gate Arrays) embedded in an ASIC (Application-Specific Integrated Circuits). Basically, a shift/interface system is coupled between the FPGAs and the ASIC. During normal operation, the shift/interface system electrically couples the FPGAs to the ASIC. During the testing of the FPGAs, the shift/interface system scans in FPGA test data in series, then feeds the FPGA test data to the FPGAs, then receives FPGA response data from the FPGAs, and then scans out the FPGA response data in series. During the testing of the ASIC, the shift/interface system scans in ASIC test data in series, then feeds the ASIC test data to the ASIC, then receives ASIC response data from the ASIC, and then scans out the ASIC response data in series.

Mechanism to provide test access to third-party macro circuits embedded in an ASIC (application-specific integrated circuit)

Novel structures and testing methods for the FPGAs (Field-Programmable Gate Arrays) embedded in an ASIC (Application-Specific Integrated Circuit). Basically, a shift/interface system is coupled between the FPGAs and the ASIC. During normal operation, the shift/interface system electrically couples the FPGAs to the ASIC. During the testing of the FPGAs, the shift/interface system scans in FPGA test data in series, then feeds the FPGA test data to the FPGAs, then receives FPGA response data from the FPGAs, and then scans out the FPGA response data in series. During the testing of the ASIC, the shift/interface system scans in ASIC test data in series, then feeds the ASIC test data to the ASIC, then receives ASIC response data from the ASIC, and then scans out the ASIC response data in series.

Disclosed is an integrated circuit chip structure that has a chip level test access port (TAP) controller and a plurality of embedded TAPs connected to the chip level TAP. Because the embedded TAPs have lengths that differ from the chip level TAP IR, and the embedded TAP IR lengths may differ from each, the chip level TAP includes a flexible length instruction register architecture adapted to accommodate the different length instruction registers of the embedded TAPs while using a constant length chip level instruction register definition for all IR accesses through the chip level TAP. Further, the invention includes selection logic adapted to actively connect only a single embedded TAP to the chip level TAP at a time.

Access method for embedded JTAG TAP controller instruction registers

A method, module, and program product for detecting signal strengths in a hardware description language, such as Verilog, that does not provide for such detection. The method includes the steps of creating a wired net configuration that provides for a data input signal and a controlled reference signal; varying the controlled reference signal based on a desired signal strength to be detected; and comparing the input signal with the controlled reference signal to determine if the desired signal strength has been detected.

Multi-valued or single strength signal detection in a hardware description language

A system and method is provided to accurately model bidirectional wire I/O using hardware description language (HDL). The preferred model and method uses an HDL model that provides two parallel paths between ports of the bidirectional wire I/O. During simulation, the ports are monitored for activity. When an event is detected on either port, the model checks both ports to see if they are different values. If the ports are different values, one of the two parallel paths is enabled and the other disabled. For example, the model enables the path in which the new signal has appeared and thus passes the signal to the other port. The preferred model allows for the use of HDL elements that support full timing annotation. The preferred embodiment also removes the possibility of high impedance transition error that can result from false transitions to a high impedance state.

Bidirectional wire I/O model and method for device simulation

Video subsystem power savings are achieved by shutting off power to unused subcircuits during blanking. Digital circuitry within the video subsystem not used during blanking is shut-down by turning off the clock thereto. Analog circuitry within a digital to analog converter is shut-down by turning off the constant current reference thereto. A functional unit containing digital circuitry within a serializer palette digital to analog converter (SPDAC) is shut-down by turning off the clock thereto during system operation in a mode where the functional unit is not utilized. A computer system having a monochrome display saves power by shutting off DAC digital circuitry clocks and DAC analog circuitry constant current references of all DACs but one. A portable computer with a liquid crystal display (LCD), a SPDAC for driving an external display and a LCD controller, saves power by shutting down video subsystem functional units and analog DAC circuitry not used for driving the LCD. Digital circuitry within the LCD controller is shut-down when an external display is being driven. In a portable computer operating in a SUSPEND state, video subsystem functional units are shut-down.

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Milton, VT, United States of America

Richard J Grupp