Abstract: 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.

Abstract: 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.

Abstract: The present inventions are related to systems and methods for circuit implementation, and more particularly to systems and methods for securing data in a circuit.

Abstract: 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.

Abstract: An integrated circuit comprises a primary input adapted to receive a test control signal, a primary output, and logic circuits having inputs coupled to the primary input via respective fan-out paths of the primary input. The integrated circuit further includes first test circuitry configured for testing a designated portion of the integrated circuit in a first test mode of operation with the test control signal at a first logic value, and second test circuitry coupled between the inputs of the logic circuits and the primary output and configured for testing of the fan-out paths in a second test mode of operation in which the test control signal takes on both the first logic value and a second logic value associated with a functional mode of operation. The primary input, primary output, logic circuits and test circuitry may be associated with a particular circuit core of the integrated circuit.

Abstract: 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.

Abstract: 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.

Abstract: A SCAN chain architecture for each path in a circuit having combinational paths includes a control mechanism to control one or more flip flops and multiplexers to direct operational or test signals. Operational signals are sent along at least one combinational path to a pull-up/pull-down for at least one input/output pad and an operational voltage is recorded. Test signals are sent along at least one alternative path to an alternative input/output and a test voltage is recorded. The operational voltage is compared to the test voltage to identify a combinational path fault.

Abstract: A system includes an integrated circuit. The integrated circuit includes at least one scan chain group. A particular scan chain group of the at least one scan chain group includes at least one scan chain and at least one spare scan chain. The at least one scan chain of the particular scan chain group includes a particular scan chain. The at least one spare scan chain of the particular scan chain group includes a particular spare scan chain. The particular spare scan chain is configured to bypass the particular scan chain.

Abstract: 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.

Abstract: 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.

Abstract: A method is disclosed for independent repair signature load into a repairable memory within a chip set of a design without halting operation of other repairable memories within the design. At initial power up, the repair signature is received from nonvolatile memory and parallelly stored within a memory repair register and within a local memory repair shadow register. During intermediate power ups after an operational power savings scheme shut down, the method avoids serially re-loading the signature from the nonvolatile memory and loads the repair signature from the local memory repair shadow register. During local repair signature loading, the method disables the chip select for the memory to prevent memory operations until the repair signature is fully loaded.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 control circuitry configured to control selective application of at least a particular one of a plurality of reset signals to reset inputs of at least a subset of the scan cells of the scan chain. For example, the control circuitry may comprise a first reset multiplexer configured to select between a first functional mode reset signal and a first scan mode reset signal for application to reset inputs of respective scan cells of the scan chain, and an additional multiplexer configured to select between an additional functional mode reset signal and an additional scan mode reset signal for application to reset inputs of respective internal flip-flops of the additional circuitry.