A ground bounce generator includes a resistor and at least one switch coupled in parallel with the resistor. The ground bounce generator is in a device under test circuit including a source, at least one ground bounce generator, at least one device under test, and a ground. The device under test is coupled in series between the source and the ground bounce generator. The device under test and the ground bounce generator are coupled in series between the source and the ground.

A signal input/output circuit is provided with an input line, a common output line, a plurality of individual output lines, relay switches, and resistor elements. The common output line is connected to a comparator. The common output line synthesizes response signals transmitted from a plurality of devices under test (DUT), and transmits a synthesized response signal generated by synthesizing, into one signal, the response signals outputted from the respective DUTs. In response to a test signal transmitted from a pattern generator, the comparator compares the synthesized response signal with a threshold value.

According to one embodiment, a semiconductor memory device includes: a first delay circuit configured to delay a first signal and provide a variable delay time; a first select circuit configured to select a second signal or a third signal based on the first signal delayed by the first delay circuit; a first output buffer configured to output a fourth signal based on a signal selected by the first select circuit; a first output pad configured to externally output the fourth signal; and a counter configured to count a number of times the fourth signal is output.

A protection circuit can be applied in a chip, and include: a first protection unit and a first element to be protected, wherein the first protection unit is configured to receive a first input signal and a control signal, and is configured to output a first output signal, the first element to be protected includes a first P-type transistor, and a gate of the P-type transistor is configured to receive the first output signal. When the chip enters a burn-in test, the first output signal is a high-level signal.

Embodiments of the present application provide a self-refresh frequency detection method, including: writing data to at least one wordline in a memory; performing a self-refresh operation on the memory; setting, after a clock enable signal changes to a low level, a duration of the low level; performing a reading operation on the memory at a positive trip point of the clock enable signal; acquiring a plurality of reading results corresponding to a plurality of durations of the low level; and obtaining a self-refresh frequency of the memory according to the plurality of durations of the low level and the plurality of reading results. The embodiments of the present application are conducive to improving the simplicity of self-refresh frequency detection.

A variety of applications can include systems and methods that include a memory system tester having an analyzer coupled to a test flow controller. The test flow controller can be arranged to generate test signals to a memory system with the analyzer arranged to couple to test pads of a package platform for the memory system. The analyzer can provide data to the test flow controller to conduct testing and/or debugging of the memory system, with the data based on real time monitoring of the test pads of the package platform. In various embodiments, the analyzer can provide data feedback to the test flow controller in real time such that the test flow controller can control the flow of test signals to the memory system in real time. Additional apparatus, systems, and methods are disclosed.

A multiple operating-mode comparator system can be useful for high bandwidth and low power automated testing. The system can include a gain stage configured to drive a high impedance input of a comparator output stage, wherein the gain stage includes a differential switching stage coupled to an adjustable impedance circuit, and an impedance magnitude characteristic of the adjustable impedance circuit corresponds to a bandwidth characteristic of the gain stage. The comparator output stage can include a buffer circuit coupled to a low impedance comparator output node. The buffer circuit can provide a reference voltage for a switched output signal at the output node in a higher speed mode, and the buffer circuit can provide the switched output signal at the output node in a lower power mode.

A semiconductor apparatus includes a first chip that generates a first oscillator signal in response to a detection enable signal and activates a ZQ circuit in response to a ZQ enable signal, and a second chip generates the ZQ enable signal by comparing frequencies of the first oscillator signal and a second oscillator signal with each other in response to the detection enable signal.

An electronic device includes a memory device receiving a power supply voltage, a data strobe signal, and a data signal, and a system-on-chip that exchanges data with the memory device using the data strobe signal and the data signal. The system-on-chip performs write training that measures a magnitude of a delay of the data strobe signal due to variation in the level of the power supply voltage and adjusts a delay of the data signal using a result of the write training.

A circuit includes a dynamic core data register (DCDR) cell that includes a data register, a shift register and an output circuit to route the output state of the data register or the shift register to an output of the DCDR in response to an output control input. A clock gate having a gate control input controls clocking of the shift register in response to a first scan enable signal. An output control gate controls the output control input of the output circuit and controls which outputs from the data register or the shift register are transferred to the output of the output circuit in response to a second scan enable signal. The first scan enable signal and the second scan enable signal to enable a state transition of the shift register at the output of the DCDR.