Intel Corporation

International Business Machines Corporation

Talal K Jaber

David M Wu

Anil K Sabbavarapu

Ming Lei Zhang

Sang Hoo Dhong

Terry I Chappell

Larry Edward Thatcher

Michael Kevin Ciraula

Rudolf Adriaan Haring

Srinivas Patil

Mark S Milshtein

Johnny James LeBlanc

Ronald Gene Walther

Chih-Jen M Lin

Steven Arthur Schmidt

Edward Seewann

Grant W McFarland

Paven R Sunkerneni

Max Eduardo De Ycaza

Pho Hoang Nguyen

Madhukar K Reddy

A scan architecture and design methodology yielding significant reduction in scan area and power overhead is generally presented. In this regard, an apparatus is introduced comprising a plurality of combinatorial logic clouds, scan cells coupled with the combinatorial logic clouds, the scan cells to load test vectors, wherein the scan cells comprise a plurality of first type scan cells and second type scan cells sequentially coupled with separate combinatorial logic cloud outputs, and a first scan clock and a second scan clock, wherein the first scan clock controls the first type scan cells and the second scan clock controls the second type scan cells. Other embodiments are also described and claimed.

Scan architecture and design methodology yielding significant reduction in scan area and power overhead

In one embodiment, the present invention includes a processor having a plurality of logical units to perform operations on data. Each unit may include a multiple input shift register (MISR) at an input of the logical unit to collect and compress data from input signals to the unit. In turn, each MISR may includes bit cells, each having a first cell to receive incoming data and controlled by a first clock signal, a second cell to receive an output of the first cell and controlled by a second clock signal, a mask cell to receive an output of the second cell and to generate a mask signal responsive to a mask clock signal, and a multiplexer coupled between the first and second cells. Other embodiments are described and claimed.

Common test logic for multiple operation modes

A sequential scan cell includes an input port for functional data and an input for scan test data. The input for scan test data is an input to a master scan flip-flop coupled to a slave scan flip-flop defining a scan test circuit. Such a scan test circuit is coupled to the functional circuit of the sequential scan cell such that the path for a functional signal is not through the scan test circuit, imparting no performance penalty to the functional signal. Scan test data is scanned in and out of the sequential cell by two non-overlapping scan clocks that are active only when system functional clocks are in an off state.

Test scan cells

A testing architecture for testing a complex integrated circuit in which each functional unit may be tested independently of the others. Embodiments of the invention allow testing of functional units to take place at slower or faster clock speeds than other portions of the processor without incurring delay or other adverse timing effects.

Flexible scan architecture

A method and apparatus are presented for on-chip testing of circuits in testing channels. In an embodiment of the present invention, the system includes a weight selector that allows for a wide variety of weighting of test data that is to be supplied to the testing channels. For example, the weight selector may be used to weight all bits in all channels or individual bits in a particular channel. Clock control and diagnostic logic may also be provided to selectively supply scan, functional, and/or stop clock signals to the testing channels. Channel filtering logic may be also provided to mask output data from a selected testing channel as desired. The method and apparatus may provide improved testing performance and power savings.

Microprocessor on-chip testing architecture and implementation

According to some embodiments, a circuit includes a Domino state element, a master latch to receive a first clock signal and to store a value in the Domino state element in response to the first clock signal, and a slave latch to receive a second clock signal and to output the value in response to the second clock signal. Some embodiments provide a first state element coupled to a first node, a master latch coupled to the first state element, the master latch to receive a first storage signal, a first load signal, a first clock signal and a first scan value signal, a second state element coupled to a second node, the second node sequential to the first node, and a slave latch coupled to the second state element, the slave latch to receive a second storage signal, a second load signal, a second clock signal and a second scan value signal.

Scan cell systems and methods

A system for testing a high speed integrated circuit includes a test device having a test clock with a first maximum frequency for performing level sensitive scan design (LSSD) testing of the integrated circuit device under test, a frequency multiplier circuit for multiplying the test clock signal to a higher second frequency capable of operating the device under test, and a finite state machine for generating a first internal clock for testing the device under test. In a practical embodiment, the internal clock speed may be running at a frequency many multiples of the test clock. Alternatively, a method of testing a device under test (DUT) at design speed includes running a predetermined group of tests with a test device operating at a lower speed than the design speed; incorporating LSSD or boundary scan test techniques in the device under test, together with a frequency multiplying device; generating a global clock for the device under test from the frequency multiplying circuit and using a finite state machine as a synchronizer and pulse generator to control a capture clock with respect to the global clock.

Apparatus and method for testing high speed components using low speed

A test apparatus and method for design verification of at least one microprocessor chip includes a compatible Joint Task Action Group (JTAG) terminal for access to a plurality of computer functional units contained in the chip. A test input terminal included in the JTAG terminal receives a scan string, the string being coupled to each computer functional unit through a first multiplexer. The scan input string is separated by the JTAG terminal under program control into a series of dedicated scan strings, each dedicated scan string being supplied to a selected functional unit through the first multiplexer. Each functional unit includes start and stop scan clocks for testing the functional under program control using the dedicated scan train for the functional unit. A test output terminal included in the JTAG terminal is coupled to each functional unit through a second multiplexer. The test results of the dedicated scan string under control of the scan clock are supplied to the output terminal through the second multiplexer. The compatible JTAG terminal includes further elements for controlling the scan clocks to select a targeted functional unit for testing purposes while the scan strings for non-targeted functional units remain in an inactive state.

Apparatus and methods for testing a microprocessor chip using dedicated

A high performance register that can be used as a pipelined register in logic chips that are designed using a pulsed logic methodology is described. The register features minimal setup time, pulse catching and pulse launching. The register circuitry complies with and implements a circuit-level test methodology for pulsed logic that features the ability to inhibit the reset of pulses, to force resets and to operate the circuits in a pseudo static mode. The register also complies with the level sensitive scan design (LSSD) methodology. Also described is a state-holding static master-slave register that complies with a pulsed logic design methodology, the register exhibiting an automatic power reduction feature and a simplified modular register bit design which can easily be adapted to either static domino or pulsed logic. The register is also LSSD compliant. Also described is the means and method for allowing static transmission gate input registers to comply with the static evaluate test mode. The automatic power reduction feature can be extended to downstream logic.

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Austin, TX, United States of America

Talal K Jaber