In one embodiment, a device comprises: a first die having disposed thereon a first plurality of latches wherein ones of the first plurality of latches are operatively connected to an adjacent one of the first plurality of latches; and a second die having disposed thereon a second plurality of latches wherein ones of the second plurality of latches are operatively connected to an adjacent one of the second plurality of latches. Each latch of the first plurality of latches on said first die corresponds to a latch in the second plurality of latches on said second die. Each set of corresponding latches are operatively connected. A scan path comprises a closed loop comprising each of said first and second plurality of latches. One of the second plurality of latches is operatively connected to another one of the second plurality of latches via an inverter.

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.

A non-transitory computer-readable recording medium stores an analysis program for causing a computer to execute a process including: reading circuit data; trying to generate test data for a delay fault to be targeted; analyzing whether an underkill is caused when the targeted delay fault results in a redundant fault; and presenting circuit modification locations to avoid the underkill, based on an analysis result, when the underkill is caused.

A non-transitory computer-readable recording medium stores an analysis program for causing a computer to execute a process including: reading circuit data; trying to generate test data for a delay fault to be targeted; analyzing whether an underkill is caused when the targeted delay fault results in a redundant fault; and presenting circuit modification locations to avoid the underkill, based on an analysis result, when the underkill is caused.

A circuit device is provided with a first codec including a first portion of a logic circuit and a second codec including a second portion of the logic circuit. The circuit device can also include a plurality of first scan chains coupled to the first codec and configured to shift a delayed test vector onto the first codec, wherein the delayed test vector is a test vector with a phase delay. A plurality of second scan chains can be coupled to the second codec and configured to shift the test vector onto the second codec.

A semiconductor integrated circuit includes scan chains, each of which includes a serial connection of sequential circuits and performs a shift register operation in a scan test; and an integrated clock gating (ICG) chain composed by coupling, to one another, ICG circuits, each of which individually supplies a corresponding one of the scan chains with a circuit clock signal to operate the sequential circuits. In the ICG chain, an ICG enable propagation signal for controlling timing when the ICG circuits output the circuit clock signals propagates through a signal line and is input sequentially to the ICG circuits. The ICG circuits output the circuit clock signals at respective timings that are different among the scan chains.

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.

A system and method for dynamically protecting against security vulnerabilities in a reconfigurable signal chain. The system includes a signal chain formed from at least a first component connected with a second component. The first component has a set of source outputs and a first authentication block, and the second signal chain component has a set of destination inputs and a second authentication block. The system also includes a signal chain configurator that populates the first authentication block with at least one validated endpoint from the set of destination inputs. A signal chain integrity block, which is communicatively coupled with the first authentication block and the second authentication block, identifies a source-destination pair from one or more endpoint pairs formed from the at least one validated endpoint and the set of source outputs. The signal chain integrity block propagates the source-destination pair to the first authentication block and the second authentication block. The second authentication block authenticates any received input using the source-destination pair.

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.

The disclosure describes a novel method and apparatus for improving interposers that connected stacked die assemblies to system substrates. The improvement includes the addition of IEEE 1149.1 circuitry within interposers to allow simplifying interconnect testing of digital and analog signal connections between the interposer and system substrate it is attached too. The improvement also includes the additional 1149.1 controlled circuitry that allows real time monitoring of voltage supply and ground buses in the interposer. The improvement also includes the additional of 1149.1 controlled circuitry that allows real time monitoring of functional digital and analog input and output signals in the interposer. The improvement also provides the ability to selectively serially link the 1149.1 circuitry in the interposer with 1149.1 circuitry in the die of the stack.