The first logic wafer is attached to a supporting wafer, which adds sufficient depth to this bonded structure such that the first logic wafer may be thinned during the manufacturing process. The first logic wafer is thinned such that the through silicon vias may be etched in the substrate of the first logic wafer so as to provide adequate connectivity to a second logic wafer, which is bonded to the first logic wafer. The second logic wafer adds sufficient depth to this bonded structure to allow the supporting wafer to then be thinned to enable through silicon vias to be added to the supporting wafer so as to provide appropriate connectivity for the entire stacked structure. The thinned supporting wafer is retained in the finished stacked wafer structure and may comprise additional components (e.g. capacitors) supporting the operation of the processing circuitry in the logic wafers.

Test stimulus signals applied to at least one circuit under test are produced in a set of test stimulus generators as a function of test stimulus information loaded in test stimulus registers. Loading of the test stimulus information in the test stimulus registers is controlled as a function of test programming information loaded via a programming interface in a respective control register in a set of control registers. The test stimulus generators are activated as a function of the test programming information loaded in said control registers. Test outcome signals received from the at least one circuit under test are used to produce signature comparison signals, which are compared with respective programmable signature reference signals stored in a set of input signature registers, are produced in response to the signature comparison signals produced from the test outcome signals failing to match with the respective reference signals.

An integrated circuit (IC) can include a plurality of circuit blocks, wherein each circuit block includes design for testability (DFT) circuitry. The DFT circuitry can include a scan interface, wherein each scan interface is uniform with the scan interface of each other circuit block of the plurality of circuit blocks, an embedded deterministic test circuit coupled to the scan interface, wherein the embedded deterministic test circuit couples to circuitry under test, and a scan response analyzer coupled to the scan interface. The scan response analyzer is configured to operate in a selected scan response capture mode selected from a plurality of scan response capture modes. The IC can include a global scan router connected to the scan interfaces of the plurality of circuit blocks. The global scan router is configured to activate a subset of the plurality of circuit blocks in parallel for a scan test.

Electronic scan circuitry includes a decompressor (510), a plurality of scan chains (520.i) fed by the decompressor (510), a scan circuit (502, 504) coupled to the plurality of scan chains (520.i) to scan them in and out, a masking circuit (590) fed by the scan chains (520.i), and a scannable masking qualification circuit (550, 560, 580) coupled to the masking circuit (590), the masking qualification circuit (550, 560, 580) scannable by scan-in of bits by the decompressor (510) along with scan-in of the scan chains (520.i), and the scannable masking qualification circuit (550, 560, 580) operable to hold such scanned-in bits upon scan-out of the scan chains through the masking circuit (590). Other scan circuitry, processes, circuits, devices and systems are also disclosed.

A method and circuit for implementing enhanced scan data testing with decreased scan data interdependence for compressed patterns in on product multiple input signature register (OPMISR) testing through scan skewing, and a design structure on which the subject circuit resides are provided. The circuit is divided into multiple chiplets. Each chiplet includes a stump mux structure including multiple stump muxes connected in series, and a respective chiplet select is provided on shared scan inputs to respective chiplets. The chiplet select gates scan clocks, and when a chiplet is not selected the chiplet retains its data. The chiplet select enables test data to be skewed as scan data enters each chiplet.

Various aspects of the disclosed technology relate to machine learning-based chain diagnosis. Faults are injected into scan chains in a circuit design. Simulations are performed on the fault-injected circuit design to determine test response patterns in response to the test patterns which are captured by the scan chains. Observed failing bit patterns are determined by comparing the unloaded test response patterns with corresponding good-machine test response patterns. Bit-reduction is performed on the observed failing bit patterns to construct training samples. Using the training samples, machine-learning models for faulty scan cell identification are trained. The bit reduction comprises pattern-based bit compression for good scan chains or cycle-based bit compression for the good scan chains. The bit reduction may further comprise bit-filtering. The bit-filtering may comprises keeping only sensitive bits on faulty scan chains for the training samples construction.

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.

In order to generate a false failure in a logic circuit without adding a new circuit to the logic circuit, a semiconductor device includes a plurality of test points includes a test point flip-flop to fix a target node within the logic circuit to a predetermined logic level when the flip-flop holds a predetermined value. A scan chain is configured by sequentially coupling a plurality of test point slip-flops. A failure injection circuit injects a failure into the target node during the normal operation of the logic circuit, by generating failure data and by setting the generated failure data to the scan chain through a scan-in node of the scan chain.

The disclosure describes novel methods and apparatuses for accessing test compression architectures (TCA) in a device using either a parallel or serial access technique. The serial access technique may be controlled by a device tester or by a JTAG controller. Further the disclosure provides an approach to access the TCA of a device when the device exists in a daisy-chain arrangement with other devices, such as in a customer’s system. Additional embodiments are also provided and described in the disclosure.

A semiconductor device addresses to a problem in which a current consumption variation rate increases during BIST execution causing resonance noise generation in a power supply line. The semiconductor device includes a self-diagnosis control circuit, a scan target circuit including a combinational circuit and a scan flip-flop, and an electrically rewritable non-volatile memory. A scan chain is configured by coupling a plurality of the scan flip-flops. In accordance with parameters stored in the non-volatile memory, the self-diagnosis control circuit can change a length of at least one of a scan-in period, a scan-out period and a capture period, and can also change a scan start timing.