Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Ramesh C Tekumalla

Prakash Krishnamoorthy

Parag Madhani

Priyesh Kumar

Vijay Sharma

Komal Shah

Niranjan Anant Pol

Vineet Sreekumar

Narendra B Devta Prasanna

Partho Tapan Chaudhuri

Coding circuitry comprises at least an encoder configured to encode an instruction address for transmission to a decoder. The encoder is operative to identify the instruction address as belonging to a particular one of a plurality of groups of instruction addresses associated with respective distinct program constructs, and to encode the instruction address based on the identified group. The decoder is operative to identify the encoded instruction address as belonging to the particular one of a plurality of groups of instruction addresses associated with respective distinct program constructs, and to decode the encoded instruction address based on the identified group. The coding circuitry may be implemented as part of an integrated circuit or other processing device that includes associated processor and memory elements. In such an arrangement, the processor may generate the instruction address for delivery over a bus to the memory.

Instruction address encoding and decoding based on program construct groups

A computer system includes a first on-chip controller and a second on-chip controller, both connected to a control element. In normal operation, the first and second on-chip controllers operate in different clock domains. During testing, the control element causes each on-chip controller to generate a substantially similar clock signal. The substantially similar clock signals are used to test substantially similar test circuitry connected to each on-chip controller, thereby reducing overhead associated with testing. A delay may be incorporated into the path of the clock signal of one of the on-chip controllers to reduce instantaneous power draw during testing.

Integrated clock architecture for improved testing

An integrated circuit comprises scan test circuitry and at least one circuit core coupled to the scan test circuitry. The scan test circuitry comprises input and output scan chains coupled to respective input and output interfaces of the circuit core via respective functional logic blocks, and interface signal selection circuitry. The interface signal selection circuitry is configured to select a particular one of a functional input signal and a plurality of scan test input signals for application to one or more designated input signal lines of the input interface of the circuit core responsive to one or more control signals. By way of example only, the first and second scan test input signals may comprise respective first and second distinct address values and the designated input signal lines of the input interface of the circuit core may comprise address input signal lines of an embedded memory.

At-speed scan testing of interface functional logic of an embedded memory or other circuit core

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells. The integrated circuit further comprises a clock distribution network configured to provide clock signals to respective portions of the integrated circuit. The clock distribution network comprises clock gating circuitry configured to control delivery of one or more of the clock signals along respective clock signal lines of the clock distribution network at least in part responsive to a scan shift control signal that is also utilized to cause the scan cells to form a serial shift register during scan testing. The clock gating circuitry may be used to determine whether a clock delay defect that causes a scan error during scan testing will also cause a functional error during functional operation, thereby improving yield in integrated circuit manufacturing.

Integrated circuit having clock gating circuitry responsive to scan shift control signal

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells. The integrated circuit further comprises a clock distribution network configured to provide clock signals to respective portions of the integrated circuit. The clock distribution network comprises at least one clock module comprising one or more clock dividers and associated clock divider logic, and the scan test circuitry is configured to permit testing of at least a portion of the clock divider logic. A given scan chain of the scan test circuitry may comprise first and second scan cells, with the first scan cell having a scan output coupled to a scan input of the second scan cell, and the second scan cell having a data input driven by an output of the clock divider logic.

At-speed scan testing of clock divider logic in a clock module of an integrated circuit

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having a plurality of scan cells. The scan test circuitry further comprises scan enable timing control circuitry coupled between a scan enable input of the scan test circuitry and scan enable inputs of respective ones of the scan cells. The scan enable timing control circuitry is operative to control timing of a transition between a scan shift configuration of the scan cells and a functional data capture configuration of the scan cells so as to permit testing of the scan cells in the scan shift configuration.

Scan enable timing control for testing of scan cells

An integrated circuit comprises scan test circuitry, additional circuitry subject to testing utilizing the scan test circuitry, and control circuitry associated with the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells, and the associated control circuitry is coupled to at least a given one of a primary input of the integrated circuit and a primary output of the integrated circuit. The scan test circuitry is configurable by the control circuitry so as to permit testing of both an input functional path associated with the given one of the primary input and the primary output and an output functional path associated with the given one of the primary input and the primary output.

Scan circuitry for testing input and output functional paths of an integrated circuit

An integrated circuit comprises a decoder having a plurality of select signal outputs, a multiplexer having a plurality of select signal inputs subject to a specified select signal constraint, and scan test circuitry. The scan test circuitry comprises at least one scan chain having a plurality of scan cells coupled between respective ones of the select signal outputs of the decoder and respective ones of the select signal inputs of the multiplexer. The scan test circuitry is configured to control at least a given one of the scan cells so as to prevent violation of the select signal constraint in conjunction with scan testing. The multiplexer may be, for example, a one-hot multiplexer for which the select signal constraint indicates that only one of the select signal inputs should receive a logic high select signal at a particular time.

Scan test circuitry configured to prevent violation of multiplexer select signal constraints during scan testing

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having a plurality of sub-chains associated with respective distinct clock domains, and clock domain bypass circuitry configured to selectively bypass one or more of the sub-chains. The scan chain is configurable in a scan shift mode of operation to form a serial shift register that includes fewer than all of the sub-chains with at least a remaining one of the sub-chains being bypassed by the clock domain bypass circuitry so as to not be part of the serial shift register in the scan shift mode. By selectively bypassing portions of the scan chain associated with particular clock domains, the clock domain bypass circuitry serves to reduce test time and power consumption during scan testing.

Dynamic clock domain bypass for scan chains

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a scan chain having a plurality of scan cells. The integrated circuit further comprises a clock distribution network configured to provide clock signals to respective portions of the integrated circuit. The clock distribution network comprises a clock tree having clock signal lines, and clock control elements arranged in respective selected ones of the clock signal lines of the clock tree, where the clock control elements are configured to separate at least one synchronous clock domain into multiple asynchronous clock domains during scan testing. The clock control elements may be configured to reduce a number of timing exceptions produced during scan testing relative to a number of timing exceptions that would otherwise be produced if scan testing were performed using the synchronous clock domain.

Clock control for reducing timing exceptions in scan testing of an integrated circuit

An integrated circuit comprises scan test circuitry and additional internal circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a plurality of scan chains, with each such scan chain comprising a plurality of flip-flops configurable to operate as a serial shift register. The plurality of scan chains are arranged in sets of two or more parallel scan chains. The scan test circuitry further comprises multiplexing circuitry, including a plurality of multiplexers each associated with a corresponding one of the sets of parallel scan chains and configured to multiplex scan test outputs from the parallel scan chains within the corresponding one of the sets of parallel scan chains. In one embodiment, one or more of the sets of parallel scan chains comprise respective pairs of parallel scan chains with each such pair corresponding to a single original scan chain. A given one of the pairs of parallel scan chains comprises an even scan chain and an odd scan chain, formed by reordering the corresponding single original scan chain.

Integrated circuit comprising scan test circuitry with parallel reordered scan chains

A scan chain lockup latch comprises at least one latching element and data input control circuitry configured to control application of data to a data input of the latching element responsive to a scan enable signal. The lockup latch is configured for coupling between first and second scan cells of a scan chain. The scan chain may be controllable between a scan shift mode of operation and a functional mode of operation responsive to the scan enable signal. The data input control circuitry may be configured to maintain the data input of the latching element at a constant logic value when the scan chain is in its functional mode of operation such that switching activity in the latching element is suppressed. The scan chain lockup latch and the associated scan chain may be implemented in scan test circuitry of an integrated circuit, for testing additional circuitry of that integrated circuit.

Scan chain lockup latch with data input control responsive to scan enable signal

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having scan cells. The scan test circuitry further comprises transition launch mode selection circuitry configured to provide independent selection between multiple transition launch modes for each of a plurality of clock domains of the integrated circuit. The multiple transition launch modes may include, for example, at least a launch-on-shift mode and a launch-on-capture mode. These transition launch modes provide different manners of launching a given signal transition via at least one of the scan cells in a corresponding one of the clock domains. The transition launch mode selection circuitry may be configured to generate from a common shift enable signal multiple independently controllable shift enable signals for respective ones of the clock domains of the integrated circuit.

Scan test circuitry with selectable transition launch mode

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises a plurality of scan chains, including at least one wrapper cell scan chain arranged between first and second circuitry cores of the additional circuitry, with the wrapper cell scan chain comprising a plurality of wrapper cells and being configurable to operate as a serial shift register in a scan shift mode of operation. At least one of the wrapper cells of the wrapper cell scan chain comprises a flip-flop having a throughput data path that is part of a scan shift path of the wrapper cell scan chain and not part of a functional path between the first and second circuitry cores. In an HDD controller embodiment, the first and second circuitry cores may comprise respective read channel and additional cores of a system-on-chip.

Efficient wrapper cell design for scan testing of integrated

An integrated circuit comprises scan test circuitry and additional circuitry subject to testing utilizing the scan test circuitry. The scan test circuitry comprises at least one scan chain having a plurality of scan cells, wherein the scan chain is separated into a plurality of scan segments with each such segment comprising a distinct subset of two or more of the plurality of scan cells. The scan test circuitry further comprises scan segment bypass circuitry configured to selectively bypass one or more of the scan segments in a scan shift mode of operation. The scan segment bypass circuitry may comprise a plurality of multiplexers and a scan segment bypass controller. The multiplexers are arranged within the scan chain and configured to allow respective ones of the scan segments to be bypassed responsive to respective bypass control signals generated by the scan segment bypass controller.

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Breinigsville, PA, United States of America

Ramesh C Tekumalla