Abstract: Test circuits located on semiconductor die enable a tester to test a plurality of die/ICs in parallel by inputting both stimulus and response patterns to the plurality of die/ICs. The response patterns from the tester are input to the test circuits along with the output response of the die/IC to be compared. Also disclosed is the use of a response signal encoding scheme whereby the tester transmits response test commands to the test circuits, using a single signal per test circuit, to perform: (1) a compare die/IC output against an expected logic high, (2) a compare die/IC output against an expected logic low, and (3) a mask compare operation. The use of the signal encoding scheme allows functional testing of die and ICs since all response test commands (i.e. 1-3 above) required at each die/IC output can be transmitted to each die/IC output using only a single tester signal connection per die/IC output. In addition to functional testing, scan testing of die and ICs is also possible.

Abstract: Functional circuits and cores of circuits are tested on integrated circuits using scan paths. Using parallel scan distributor and collector circuits for these scan paths improves test access of circuits and cores embedded within ICs and reduces the IC's power consumption during scan testing. A controller for the distributor and collector circuits includes a test control register, a test control state machine and a multiplexer. These test circuits can be connected in a hierarchy or in parallel. A conventional test access port or TAP can be modified to work with the disclosed test circuits.

Abstract: A method and/or a system of a processor-agnostic encoded debug architecture in a pipelined environment is disclosed. In one embodiment, a method of a processor includes processing an event specified by a data processing system coupled to the processor to determine a boundary of the event, generating a matrix having combinations of the event and other events occurring simultaneously in the processor, capturing an output data of observed ones of the event and other events, and applying the matrix to generate an encoded debug data of the output data. The method may also include determining which of the combinations are valid based on an architecture of the processor. The event may be a trace-worthy event whose output value cannot be reliably predicted in an executable file in the data processing system and/or a sync event that is specified by a user of the data processing system.

Abstract: An input signal processing system is described. It comprises a first transconductance device having a first input, second input, and an output, wherein the first input is coupled to receive the input signal; a first resistor coupled to a first input of the first transconductance device, wherein the first resistor converts the input current signal to an input voltage signal; a first voltage-current converter coupled to the output, the second input, the resistor, and a low voltage supply, wherein the first voltage-current converter is operative for converting the input voltage signal to a input current signal; and a low pass filter having an input coupled to the voltage converter for filtering noise from the input current signal.

Abstract: A circuit is designed with a matched filter circuit including a plurality of fingers (700, 702, 704) coupled to receive a data symbol. Each finger corresponds to a respective path of the data symbol. Each finger produces a respective output signal. A plurality of decoder circuits (706, 708, 710) receives the respective output signal from a respective finger of the plurality of fingers. Each decoder circuit produces a respective output signal. A joint detector circuit (1310) is coupled to receive each respective output signal from the plurality of decoder circuits. The joint detector circuit produces an output signal corresponding to a predetermined code.

Abstract: Testing of integrated circuits is achieved by a test architecture utilizing a scan frame input shift register, a scan frame output shift register, a test controller, and a test interface comprising a scan input, a scan clock, a test enable, and a scan output. Scan frames input to the scan frame input shift register contain a test stimulus data section and a test command section. Scan frames output from the scan frame output shift register contain a test response data section and, optionally, a section for outputting other data. The command section of the input scan frame controls the test architecture to execute a desired test operation.

Abstract: The disclosure describes a novel method and apparatus for making device TAPs addressable to allow device TAPs to be accessed in a parallel arrangement without the need for having a unique TMS signal for each device TAP in the arrangement. According to the disclosure, device TAPs are addressed by inputting an address on the TDI input of devices on the falling edge of TCK. An address circuit within the device is associated with the device's TAP and responds to the address input to either enable or disable access of the device's TAP.

Abstract: The peripheral circuitry (350, 360, ESD, BH) of an integrated circuit die on a wafer is tested without physically contacting the bond pads of the die.

Abstract: Scan distributor, collector, and controller circuitry connect to the functional inputs and outputs of core circuitry on integrated circuits to provide testing through those functional inputs and outputs. Multiplexer and demultiplexer circuits select between the scan circuitry and the functional inputs and outputs. The core circuitry can also be provided with built-in scan distributor, collector, and controller circuitry to avoid having to add it external of the core circuitry. With appropriately placed built-in scan distributor and collector circuits, connecting together the functional inputs and outputs of the core circuitry also connects together the scan distributor and collector circuitry in each core. This can provide a hierarchy of scan circuitry and reduce the need for separate test interconnects and multiplexers.

Abstract: A first transistor produces a first voltage in response to a first current signal. A first resistor is coupled between the first transistor and a low voltage supply. A transconductor has a first input receiving the first voltage and producing a second current signal in response to differences between signals received on the first input and a second input. A second transistor is coupled to the second input and produces a third current signal in response to the second current signal. A third transistor, coupled to the second transistor and the second input, produces an output current signal in response to the third current signal. The first transistor is scaled to the third transistor by the inverse of a gain factor. A second resistor is coupled between the third transistor and a low voltage supply. The first resistor is scaled to the second resistor by the gain factor.

Abstract: The disclosure describes a novel method and apparatus for allowing response data output from the scan outputs of a circuit under test to be formatted and applied as stimulus data input to the scan inputs of the circuit under test. Also the disclosure described a novel method and apparatus for allowing the response data output from the scan outputs of a circuit under test to be formatted and used as expected data to compare against the response data output from the circuit under test. Additional embodiments are also provided and described in the disclosure.

Abstract: A test architecture accesses IP core test wrappers within an IC using a Link Instruction Register (LIR). An IEEE P1500 standard is in development for providing test access to these individual cores via a test structure called a wrapper. The wrapper resides at the boundary of the core and provides a way to test the core and the interconnections between cores. The test architecture enables each of the plural wrappers in the IC, including wrappers in cores embedded within other cores, with separate enable signals.

Abstract: A Scan-BIST architecture is adapted into a low power Scan-BIST architecture. A generator 102, compactor 106, and controller 110 remain the same as in the known art. The changes between the known art Scan-BIST architecture and the low power Scan-BIST architecture involve modification of the known scan path into scan path 502, to insert scan paths A 506, B 508 and C 510, and the insertion of an adaptor circuit 504 in the control path 114 between controller 110 and scan path 502.

Abstract: A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Abstract: According to an aspect of the present invention, statistical timing analysis is applied with respect to a stress degradation that occurs in fabricated integrated circuits (IC) when used for a long duration. The circuit design may be suitably modified to account for the degradations (e.g., those caused by NBTI and CHC for transistors, those caused due to electromigration in case of interconnects). As a result, the fabricated ICs may be less susceptible to such degradations. The features are extended to model complex circuit blocks and also account for different degrees of stress that different circuit blocks are subjected to, in a same age of operation.

Abstract: A device test architecture and interface is provided to enable efficient testing embedded cores within devices. The test architecture interfaces to standard IEEE 1500 core test wrappers and provides high test data bandwidth to the wrappers from an external tester. The test architecture includes compare circuits that allow for comparison of test response data to be performed within the device. The test architecture further includes a memory for storing the results of the test response comparisons. The test architecture includes a programmable test controller to allow for various test control operations by simply inputting an instruction to the programmable test controller from the external tester. The test architecture includes a selector circuit for selecting a core for testing. Additional features and embodiments of the device test architectures are also disclosed.

Abstract: An architecture for testing a plurality of circuits on an integrated circuit is described. The architecture includes a TAP Linking Module located between test pins on the integrated circuit and 1149.1 Test Access Ports (TAP) of the plurality of circuits to be tested. The TAP Linking Module operates in response to 1149.1 scan operations from a tester connected to the test pins to selectively switch between 1149.1 TAPs to enable test access between the tester and plurality of circuits. The TAP Linking Module's 1149.1 TAP switching operation is based upon augmenting 1149.1 instruction patterns to affix an additional bit or bits of information which is used by the TAP Linking Module for performing the TAP switching operation.

Abstract: Topology discovery of a target system having a plurality of components coupled with a scan topology may be performed by driving a low logic value on the data input signal and a data output signal of the scan topology. An input data value and an output data value for each of the plurality of components is sampled and recorded. A low logic value is then scanned through the scan path and recorded at each component. The scan topology may be determined based on the recorded data values and the recorded scan values.

Abstract: A memory array is provided having a memory cell coupled to a read word line and a write word line of the memory array and peripheral circuits for reading and writing to the memory cell. The memory cell comprises a storage element for storing a logical state of the memory cell powered at a reduced voltage during at least one functional operation and a write access circuit configured to connect the storage element to at least a first write bit line in the memory array in response to a write signal on the write word line for writing the logical state to the memory cell. The memory cell further comprises a read access circuit including an input node connected to the storage element and an output node connected to a read bit line of the memory array. The read access circuit is enabled and configured to read the logic state of the storage element in response to a read signal on the read word line.

Abstract: In a first embodiment a TAP 318 of IEEE standard 1149.1 is allowed to commandeer control from a WSP 202 of IEEE standard P1500 such that the P1500 architecture, normally controlled by the WSP, is rendered controllable by the TAP. In a second embodiment (1) the TAP and WSP based architectures are merged together such that the sharing of the previously described architectural elements are possible, and (2) the TAP and WSP test interfaces are merged into a single optimized test interface that is operable to perform all operations of each separate test interface.