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.

Aspects of the invention include a phase rotator, that is located at a built-in self-test (BIST) path of a receiver, receiving a clock signal from an on-chip clock. The phase rotator shifts the phases of the clock signal. The phase rotator transmits the shifted clock signal to a binary sequence generator, that is located at the receiver. The binary sequence generator outputs a binary sequence, where the binary sequence generator is driven by the shifted clock signal.

Testing of die on wafer is achieved by; (1) providing a tester with the capability of externally communicating JTAG test signals using simultaneously bidirectional transceiver circuitry, (2) providing die on wafer with the capability of externally communicating JTAG test signals using simultaneously bidirectional transceiver circuity, and (3) providing a connectivity mechanism between the bidirectional transceiver circuitry's of the tester and a selected group or all of the die on wafer for communication of the JTAG signals.

This disclosure describes die test architectures that can be implemented in a first, middle and last die of a die stack. The die test architectures are mainly the same, but for the exceptions mentioned in this disclosure.

The disclosure describes a novel method and apparatuses for allowing a controller to select and access different types of access ports in a device. The selecting and accessing of the access ports is achieved using only the dedicated TDI, TMS, TCK, and TDO signal terminals of the device. The selecting and accessing of device access ports can be achieved when a single device is connected to the controller, when multiple devices are placed in a daisy-chain arrangement and connected to the controller, or when multiple devices are placed in a addressable parallel arrangement and connected to the controller. Additional embodiments are also provided and described in the disclosure.

An integrated circuit for transition fault testing comprises a synchronizing circuit including a first set of shift registers coupled to receive a scan enable signal and to provide a synchronizing signal based on the scan enable signal; a clock leaker circuit coupled to the synchronizing circuit and including a second set of shift registers coupled to receive a first clock signal based on the synchronizing signal and to provide a second clock signal that includes a set of pulses; and a multiplexer (MUX) that includes a first input coupled to receive a shift clock, a second input coupled to the clock leaker circuit to receive the second clock signal, and an output configured to provide an output clock signal that includes a second set of pulses.

A test and measurement system includes a clock recovery circuit configured to receive a signal from a device under test and to produce a pattern trigger signal, a flash array digitizer having an array of counters having rows and columns configured to store a waveform image representing the signal received from the device under test, a row selection circuit configured to select a row in the array of counters, and a ring counter circuit configured to receive a clock signal, select a column in the array of counters, produce end of row signals, and produce a fill complete signal upon all of the columns having been swept, the fill complete signal indicating completion of the waveform image, an equivalent time sweep logic circuit configured to receive the pattern trigger signal and the end of row signals from the ring counter and to produce the clock signal with a delay to increment a clock delay to the ring counter until the fill complete signal is received, and a machine learning system configured to receive the waveform image and provide operating parameters for the device under test. A test and measurement system includes a flash array digitizer having an array of counters having rows and columns configured to store a waveform image representing a signal received from a device under test, a row selection circuit configured to select a row in the array of counters, a column selection circuit configured to select a column in the array of counters, a sample clock connected to the row selection circuit and the column selection circuit, and a machine learning system configured to receive the waveform image from the flash array digitizer and provide operating parameters for the device under test.

A core partition circuit comprises a first decompression circuit, a second decompression circuit, a first switching circuit, an wrapper scanning circuit, a first compression circuit, a second compression circuit and a second switching circuit. The first and second decompression circuits decompress an input signal. The first switching circuit outputs the output signal of the first decompression circuit or the second decompression circuit according to a first control signal. The wrapper scanning circuit receives the output signal of the first decompression circuit or the second decompression circuit to scan the internal or the port of the core partition circuit. The first and second compression circuits respectively compress the internal logic and the port logic of the core partition circuit. The second switching circuit outputs the compressed internal logic or port logic of the core partition circuit according to the first control signal.

A detection circuit for detecting a clock signal includes a multiplexer, a digital-to-analog converter, a comparator, and a counter. The multiplexer outputs either a first signal or a second signal as a selection signal. The digital-to-analog converter outputs a reference voltage according to the selection signal. The comparator compares the clock signal to the reference voltage to generate a comparison signal. The counter counts a reference clock signal to generate an overflow signal, and resets the overflow signal according to the comparison signal. The overflow signal indicates the amplitude of the clock signal.

Embodiments herein relate to an apparatus comprising: a first circuit with a plurality of stages; and a second circuit communicatively coupled with the first circuit, wherein the second circuit includes: a plurality of tap lines, wherein respective tap lines of the plurality of tap lines are coupled between two stages of the plurality of stages; and the logic, wherein the logic is to identify, based on an average voltage measurement of at least one tap line, a status of a duty-cycle of a signal propagating through a stage of the first circuit. Other embodiments may be described and claimed.