Delay measuring circuit and delay measuring method of device to be measured

Abstract

The invention provides a delay measuring circuit and a delay measuring method of a device to be measured. The delay measuring circuit comprises a loop oscillator and a periodic measuring unit. The periodic measuring unit is suitable for measuring oscillation period of the loop oscillator, and obtaining delay of the device to be measured according to the oscillation period of the loop oscillator. The loop oscillator comprises at least five oscillating units that are directly or indirectly connected in series into a loop. Each oscillating unit comprises the device to be measured, a pre-switch and a bypass switch. Under the function of a group of control signals, each pre-switch and bypass switch in the loop oscillator are on or off to enable the devices to be measured in the oscillating units of the loop oscillator to be connected in series to form an oscillation loop; and in each oscillating unit controlled to be connected in series in the oscillation loop, the pre-switch and the bypassswitch have and only have one conduction. The delay measuring circuit can greatly improve delay measuring precision of the device to be measured.

Description

technical field [0001] The invention relates to an electronic process deviation detection technology, in particular to a delay measurement circuit and a delay measurement method of a device to be tested. Background technique [0002] In chip design, delay time is one of the most important electrical parameters to measure electronic devices. Due to the existence of electronic process deviations, the delay time of the electronic devices on the chip is different, therefore, it is necessary to measure the delay time of the electronic devices. At the same time, on the chip, a plurality of electronic devices of the same type in the fixed area may also have differences in delay times, and it is also very important to detect deviations in delay times between electronic devices of the same type in the fixed area. Wherein, the electronic device may be a logic gate device, such as an inverter, an AND gate, etc., or may be a combination circuit formed by a logic gate device, which is n...

AI Technical Summary

Problems solved by technology

However, when configuring the ring oscillator, when the multiplexer is switched, the equivalent load and drive strength of the DUT in the ring oscillator will be different, which will seriously affect the delay of the DUT Measurement accuracy

[0006] Therefore, it is difficult to guarantee the measurement accuracy of the device under test in the delay measurement circuit in the prior art

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