A circuit comprises: a bit-flipping signal generation device comprising a storage device and configured to generate a bit-flipping signal based on bit-flipping location information, the storage device configured to store the bit-flipping location information for a first number of bits, the bit-flipping location information obtained through a fault simulation process; a pseudo random test pattern generator configured to generate test patterns based on the bit-flipping signal, the pseudo random test pattern generator comprising a register configured to be a linear finite state machine, the register comprising storage elements and bit-flipping devices, each of the bit-flipping devices coupled to one of the storage elements; and scan chains configured to receive the test patterns, wherein the bit-flipping signal causes one of the bit-flipping devices to invert a bit of the register each time a second number of test patterns is being generated by the pseudo random test pattern generator during a test.

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.

A reconfigurable JTAG includes, in part, a core logic, a boundary scan chain cell, one or more reconfigurable blocks (RBs), and a reconfigurable block (RB) programming module. The RBs may include, in part, one or more reconfigurable boundary scan chain blocks (RBB) adapted to couple the boundary scan chain cell to the core logic and to input/output (I/O) ports of the reconfigurable JTAG. The RBs may also include, in part, one or more additional reconfigurable logic (ARL) blocks to provide enhanced logic for locking operations. The RB programmable module may communicate with a memory storing data for configuring the RBBs and ARLs. The RB programming module may configure the RBBs and ARLs based at least in part on the data stored in the memory to disable access to the I/O ports of the JTAG. The RB programming module may configure the RBBs to encrypt the I/O ports in accordance with a cipher algorithm. The RB programming module may also configure the RBBs and ARLs to compare a counter's count to a predefined time and lock the I/O ports after an expiration of the predefined time.

The invention describes an integrated circuit, comprising a functional circuit structure which is configured to provide a functionality; and a test structure configured to set a signal, which is coupled to the functional circuit structure, to a test value in response to a magnetic field impulse, to control a test of the integrated circuit. The invention also describes an apparatus and a method for testing an integrated circuit and a computer program implementing the method. This invention provides a time-effective and cost-effective concept of component testing using magnetic interaction.

A processor comprises an exchange, a plurality of columns, and a plurality of exchange scan chains. The exchange comprises a plurality of exchange paths, each comprising a set of exchange path portions, for transmitting data between processing units. Each of the plurality of column comprises processing units, each processing unit connected to output data to a respective exchange path, and column pipe circuitry for providing a controllable path between the exchange and the processing units. The column pipe circuitry comprises a column wrapper chain for preventing a scan test signal from passing between the exchange paths and the processing units. The exchange scan chains enable scan testing of the exchange paths. Each exchange scan chain comprises a plurality of scan chain segments, each scan chain segment comprises an exchange path portion connected to at least one of the processing units of at least one of the columns of the processor.

A circuit system includes a first circuit, a second circuit, and a comparator. The second circuit and the first circuit have substantially identical structures. In a testing mode, the circuit system controls the first circuit and the second circuit to perform the same testing operation synchronously. During the process of the testing operation, the comparator keeps compares a first intermediate signal internally generated by the first circuit and a second intermediate signal corresponding to the first intermediate signal that is internally generated by the second circuit. When the first intermediate signal is different from the second intermediate signal, the circuit system controls the first circuit and the second circuit to stop the testing operation and controls the first circuit and the second circuit to perform a scan dump operation in order to record signals transmitting by the first circuit and signals transmitting by the second circuit.

A combinational circuit block has input pins configured to receive input digital signals and output pins configured to provide output digital signals as a function of the input digital signals received. A test input pin receives a test input signal. A test output pin provides a test output signal as a function of the test input signal received. A set of scan registers are selectively coupled to either the combinational circuit block or to one another so as to form a scan chain of scan registers serially coupled between the test input pin and the test output pin. The scan registers in the set of scan registers are clocked by a clock signal. At least one input register is coupled between the test input pin and a first scan register of the scan chain. The at least one input register is clocked by an inverted replica of the clock signal.

An integrated circuit includes a flip-flop circuit and a gating circuit. The flip-flop circuit is arranged to receive an input data for generating a master signal during a writing mode according to a first clock signal and a second clock signal, and to output an output data according to the first clock signal and the second clock signal during a storing mode. The gating circuit is arranged for generating the first clock signal and the second clock signal according to the master signal and an input clock signal. When the input clock signal is at a signal level, the first clock signal and the second clock signal are at different logic levels. When the input clock signal is at another signal level, the first clock signal and the second clock signal are at a same logic level determined according to a signal level of the master signal.

An Integrated Circuit (IC) includes a storage element and control circuitry. The control circuitry is configured to select, responsively to a scan-enable control, between a functional-data input and a scan-data input to serve as an input to the storage element, to selectively disable toggling of an output of the storage element, responsively to a clock-enable control, by gating a clock signal provided to the storage element, and, while the clock-enable control indicates that the output of the storage element is to be disabled from toggling, to select the input of the storage element to be the scan-data input.

One exemplary embodiment describes an integrated circuit, comprising a multiplicity of scan flip-flops, a multiplicity of ring oscillator circuits, wherein each ring oscillator circuit comprises a chain of logic gates comprising a plurality of logic gates connected in succession, an input multiplexer for the chain, and a feedback line from an output connection of the last logic gate of the chain to a data input connection of the input multiplexer. Each ring oscillator circuit is assigned a scan flip-flop group that contains at least one of the multiplicity of scan flip-flops. The input multiplexer of the ring oscillator circuit is controlled depending on a control bit stored by the at least one scan flip-flop of the scan flip-flop group assigned to the ring oscillator circuit such that the input multiplexer outputs an output bit fed back via the feedback line to the first logic gate of the chain or that the input multiplexer outputs a input bit that is to be processed by the chain to the first logic gate of the chain. The ring oscillator circuits are assigned different scan flip-flop groups.