Abstract: This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations. In a fifth aspect of the present disclosure, an interface select circuit, FIGS. 41-49, provides for selectively using either the 5 signal interface of FIG. 41 or the 3 signal interface of FIG. 8.

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: An integrated circuit can have plural core circuits, each having a test access port that is defined in IEEE standard 1149.1. Access to and control of these ports is though a test linking module. The test access ports on an integrated circuit can be arranged in a hierarchy with one test linking module controlling access to plural secondary test linking modules and test access ports. Each secondary test linking module in turn can also control access to tertiary test linking modules and test access ports. The test linking modules can also be used for emulation.

Abstract: In a first embodiment a TAP of IEEE standard 1149.1 is allowed to commandeer control from a WSP 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. One approach provides for the TAP to maintain access and control of the TAP instruction register, but provides for a selected data register to be accessed and controlled by either the TAP+ATC or by the discrete CaptureDR, UpdateDR, TransferDR, ShiftDR, and ClockDR WSP data register control signals.

Abstract: A method implemented to test a plurality of components coupled in a star configuration, each component having a test access port (TAP) controller. The method comprises performing a capture phase of a scan operation on all of the TAP controllers in the star configuration and sequentially selecting one of the TAP controllers at a time to perform a shift state. When all of the TAP controllers have been sequentially selected to perform the shift phase, the method further comprises selecting all of the TAP controllers to perform an update phase.

Abstract: Timely testing of die on wafer reduces the cost to manufacture ICs. This disclosure describes a die test structure and process to reduce test time by adding test pads on the top surface of the die. The added test pads allow a tester to probe and test more circuits within the die simultaneously. Also, the added test pads contribute to a reduction in the amount of test wiring overhead traditionally required to access and test circuits within a die, thus reducing die size.

Abstract: A Propagation Test instruction, a Decay Test instruction and a Cycle Test instruction provide testing of DC and AC interconnect circuits between circuits including JTAG boundary scan cells. A few additions to the Test Access Port circuitry, including gating producing a Capture Test Strobe (CTS) signal, and the boundary scan cells are required to implement the additional instructions. The instructions are extensions of the conventional JTAG operating structure.

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: Scan architectures are commonly used to test digital circuitry in integrated circuits. The present invention describes a method of adapting conventional scan architectures into a low power scan architecture. The low power scan architecture maintains the test time of conventional scan architectures, while requiring significantly less operational power than conventional scan architectures. The low power scan architecture is advantageous to IC/die manufacturers since it allows a larger number of circuits (such as DSP or CPU core circuits) embedded in an IC/die to be tested in parallel without consuming too much power within the IC/die. Since the low power scan architecture reduces test power consumption, it is possible to simultaneously test more die on a wafer than previously possible using conventional scan architectures. This allows wafer test times to be reduced which reduces the manufacturing cost of each die on the wafer.

Abstract: A process of selecting alternative test circuitry within an integrated circuit enables a test access port. Scan test instruction data is loaded into an instruction register of a test access port TAP, the instruction data including information for selecting the alternative test circuitry. An Update-IR instruction update operation is performed at the end of the loading to output scan test control signals from the instruction register. A lockout signal is changed to an active state to disable the test access port and enable scan test circuits.

Abstract: This disclosure describes a reduced pin bus that can be used on integrated circuits or embedded cores within integrated circuits. The bus may be used for serial access to circuits where the availability of pins on ICs or terminals on cores is limited. The bus may be used for a variety of serial communication operations such as, but not limited to, serial communication related test, emulation, debug, and/or trace operations of an IC or core design. Other aspects of the disclosure include the use of reduced pin buses for emulation, debug, and trace operations and for functional operations.

Abstract: The disclosure describes a process and apparatus for accessing devices on a substrate. The substrate may include only full pin JTAG devices (504), only reduced pin JTAG devices (506), or a mixture of both full pin and reduced pin JTAG devices. The access is accomplished using a single interface (502) between the substrate (408) and a JTAG controller (404). The access interface may be a wired interface or a wireless interface and may be used for JTAG based device testing, debugging, programming, or other type of JTAG based operation.

Abstract: Various apparatuses, methods and systems for dual JTAG controllers with shared pins disclosed herein. For example, some embodiments provide a boundary scan apparatus having a first boundary scan circuit with a first plurality of control inputs, a second boundary scan circuit with a second plurality of control inputs, and a plurality of boundary scan control signals connected to the first plurality of control inputs on the first boundary scan circuit and to the second plurality of control inputs on the second boundary scan circuit. At least two of the plurality of boundary scan control signals are connected between the first boundary scan circuit and the second boundary scan circuit in a crossover fashion.

Abstract: An apparatus and method for self-testing a DDR memory interface are disclosed. In one aspect, a built-in-self-test (BIST) memory interface circuit includes a signal multiplier for receiving a first clock signal from a tester and outputs a multiplied clock signal. A first multiplexer is used for selecting between a test mode and a normal operating mode and provides an output signal. A delay magnitude generator is coupled to the signal multiplier to receive the multiplied clock signal and provides a second clock signal and a phase control signal. A plurality of digitally controlled delay line blocks are used for each receiving the second clock signal and the phase control signal and outputting a phase shifted data strobe output signal in response to receiving an internal data strobe input signal. A second multiplexer selects one of the internal data strobe input signals and a third multiplexer selects the phase shifted data strobe output signal that corresponds to the selected internal data strobe input signal.

Abstract: Methods and apparatus to perform frequency-domain equalization in high-speed downlink packet access (HSDPA) receivers for wireless channels with large delay-spreads are disclosed. An example method comprises computing a first frequency-domain equalizer (FDE) coefficient for a first set of multipaths, computing a second FDE coefficient for a second set of multipaths, computing a first equalized signal by equalizing a received code division multiple access (CDMA) signal with the first FDE coefficient, computing a second equalized signal by equalizing the received CDMA signal with the second FDE coefficient, delaying the first equalized signal by a delay difference between the first and the second sets, and combining the delayed first equalized signal and the second equalized signal.

Abstract: An electronic integrated circuit includes a signal path connected between the functional logic (15) thereof and an external output terminal. The signal path includes a switch (S), a bus holder circuit (121B), and an output buffer (19).

Abstract: A TAP Linking Module (TLM) couples plural TAPs, via select and enable signals, to an externally accessible IEEE 1149.1 interface. The select signals are outputs from the TAPs to the TLM, and the enable signals are output from the TLM to the TAPs. Each select signal is output in response to a special instruction scanned into a TAP's instruction register, which causes the TLM to be selected as the data register scan path between the TDI and TDO pins. A conventional data register scan operation shifts data through the TLM. Following the scan operation, the TLM outputs one enable signal to the TAPS and outputs select signals to a multiplexer to establish a TAP link configuration.

Abstract: A TAP linking module (21, 51) permits plural TAPs (TAPs 1-4) to be controlled and accessed from a test bus (13) via a single TAP interface (20).

Abstract: A shielded electronic package, comprising a semiconductor device, an insulating housing surrounding the semiconductor device and a metal coating on the insulating housing. The metal coating covers all but those portions of the insulating housing that are adjacent to connective structures on one or more mounting sides of the insulating housing.

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.