According to certain aspects, a method includes receiving an input test signal at a test input, receiving an event signal, and passing the input test signal to a test output or blocking the input test signal from the test output based on the event signal. In certain aspects, the event signal indicates an occurrence of an event in a circuit block (e.g., a memory, a processor, or another type of circuit block). The event may include a precharge operation, opening of input latches, reset of a self-time loop, arrival of a data value at a flop in a signal path, an interrupt signal indicating an error or failure in the circuit block, or another type of event.

A rapid sensing value estimation circuit and a method thereof are provided. The rapid sensing value estimation circuit includes a first sensing unit, an integration sensing circuit and a rapid estimation circuit. The rapid estimation circuit includes a clock generator, a second counter, a first digital comparator, and an arithmetic module. The clock generator generates a clock signal. The second counter counts the clock signal to generate a second count value. The first digital comparator determines whether the second count value exceeds a first predetermined count value when the first count value increases. The arithmetic module estimates the first count value at an end of an integration time according to a ratio of the second maximum count value to the second count value and the first count value when the second count value exceeding the first predetermined count value, to generate an estimated count value result.

An image sensor comprises a plurality of pixels, each pixel including: a light-receiving element that outputs an output voltage that varies in response to a photon entering; at least one comparator that compares the output voltage with a plurality of mutually-different threshold voltages and outputs a single signal each time the output voltage varies so as to exceed either of the threshold voltages; and at least one counter that counts a number of signals output by the comparator upon comparing the output voltage with the plurality of threshold voltages and outputs a count value, for each of the threshold voltages.

An image sensor comprises a plurality of pixels, each pixel including: a light-receiving element that outputs an output voltage that varies in response to a photon entering; at least one comparator that compares the output voltage with a plurality of mutually-different threshold voltages and outputs a single signal each time the output voltage varies so as to exceed either of the threshold voltages; and at least one counter that counts a number of signals output by the comparator upon comparing the output voltage with the plurality of threshold voltages and outputs a count value, for each of the threshold voltages.

A dynamical time gain controlling light sensing device generates a detection time configuration signal according to a light intensity indication signal, and generates a set of adjustment switch signals to respectively control the plurality of gain selection switches to be turned on or off according to a ratio of a real gain time and a simulation gain time within a detection time, such that an overall gain of a resolution adjustment circuit can correspond to an substitute gain lower than a set gain within the simulation gain time and correspond to the set gain within the real gain time, thereby generating an adjusted count result signal.

A system and method with AC coupling that reserves photodiode bandwidth in a biased configuration, allows optimal transimpedance amplifier performance, retains DC signal measurement capability, and does not introduce noise into the balanced detection signal.

A system and method with AC coupling that reserves photodiode bandwidth in a biased configuration, allows optimal transimpedance amplifier performance, retains DC signal measurement capability, and does not introduce noise into the balanced detection signal.

A dynamical time gain controlling light sensing device generates a detection time configuration signal according to a light intensity indication signal, and generates a set of adjustment switch signals to respectively control the plurality of gain selection switches to be turned on or off according to a ratio of a real gain time and a simulation gain time within a detection time, such that an overall gain of a resolution adjustment circuit can correspond to an substitute gain lower than a set gain within the simulation gain time and correspond to the set gain within the real gain time, thereby generating an adjusted count result signal.

The following steps are performed in connection with a photodiode circuit: a) resetting the photodiode circuit; b) determining when a photodiode voltage changes in response to illumination to reach a threshold; and c) updating a counter in response to the determination in step b). The steps a) to c) are repeated until an end of a measurement period is reached. The value of the counter at the end of the measurement period is then output to indicate an intensity of the illumination.

The following steps are performed in connection with a photodiode circuit: a) resetting the photodiode circuit; b) determining when a photodiode voltage changes in response to illumination to reach a threshold; and c) updating a counter in response to the determination in step b). The steps a) to c) are repeated until an end of a measurement period is reached. The value of the counter at the end of the measurement period is then output to indicate an intensity of the illumination.