Scan channel slicing methods and systems for testing of scan chains in an integrated circuit (IC) reduce the number of test cycles needed to effectively test all the scan chains in the IC, reducing the time and cost of testing. In scan channel slicing, rather than loading and unloading into scan chains high-power patterns having numerous switching transitions over the length of each scan chain, loading and unloading the entirety of the scan chain scan while observing it, chain load data is sliced, apportioning between the different scan chains independently observable sections (slices) of transition data in which all four bit-to-bit transitions (“0” to “0”, “0” to “1”, “1” to 0”, “1” to “1”) are ensured to exist. The remainder of the scan chain load data, which is not observed in the test procedure, can be low-transition data that consumes low dynamic power, such as mostly zeroes or mostly ones.

A circuit includes a test circuit in an integrated circuit to test signal timing of a logic circuit under test in the integrated circuit. The signal timing includes timing measurements to determine if an output of the logic circuit under test changes state in response to a clock signal. The test circuit includes a bit register that specifies which bits of the logic circuit under test are to be tested in response to the clock signal. A configuration register specifies a selected clock source setting from multiple clock source settings corresponding to a signal speed. The selected clock source is employed to perform the timing measurements of the specified bits of the bit register.

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.

A self-test circuit for an integrated circuit, having a plurality of scan chains is provided, wherein each of the scan chains has a plurality of first memory elements, a data input for providing the scan chain with test data, wherein the data input is connected to one of the first memory elements, a plurality of second memory elements, and a switching apparatus having a first and a second switching position, which switching apparatus is coupled between the first memory elements and the second memory elements and is configured to respectively connect a last one of the first memory elements to a data output in the first switching position and to respectively connect the last one of the first memory elements to a first one of the second memory elements in the second switching position.

The present disclosure describes novel methods and apparatuses for directly accessing JTAG Tap domains that exist in a scan path of many serially connected JTAG Tap domains. Direct scan access to a selected Tap domain by a JTAG controller is achieved using auxiliary digital or analog terminals associated with the Tap domain and connected to the JTAG controller. During direct scan access, the auxiliary digital or analog terminals serve as serial data input and serial data output paths between the selected Tap domain and the JTAG controller.

Provided are scan device and method of diagnosing scan chain fault. The scan device for diagnosing a fault includes a scan partition including a plurality of scan chains which include path control scan flipflops connected to scan flipflops in cascade. In the scan partition, connection paths of the scan flipflops are controllable. The connection paths of the path control scan flipflops are controlled to detect a position of a fault such that a fault range in the scan partition is reduced to diagnose the fault.

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.

Circuits, methods, and systems are provided which facilitate testing of asynchronous circuits having one or more global or local feedback loops. A circuit includes a data path and a scan path. The data path has an input configured to receive a data input signal, and a first output. The scan path includes a first multiplexer having a first input configured to receive the data input signal, a latch coupled to an output of the first multiplexer, a scan isolator coupled to an output of the latch, and a second multiplexer having a first input coupled to the first output of the data path and a second input coupled to an output of the scan isolator. The second multiplexer is configured to output a data output signal.

An integrated circuit and an electronic device including the integrated circuit are provided. An integrated circuit includes a sequential logic circuit, which includes a first scan cell that is configured to receive a scan input, and a plurality of scan cells sequentially connected in series from the first scan cell, a control unit, which is configured to receive a selection signal including an output of each of the plurality of scan cells, and is further configured to output a control signal responsive to the selection signal, and a monitoring circuit, which is configured to receive the control signal, is configured to perform first monitoring of first data at a first node that is an observation node in the sequential logic circuit responsive to the control signal, and is configured to output a result of the first monitoring to a monitoring node.

Described herein are integrated circuit chips having test circuitry designed such that independently selectable testing of different power domains using a same scan chain compressor-decompressor circuit may be performed. Also disclosed herein are integrated circuit chips having test circuitry designed such that independently selectable testing of different power domains using multiple different scan chain compressor-decompressor circuits may be performed.