Time test circuit and time test method

Abstract

The invention relates to a time test circuit. The time test circuit comprises a voltage comparator, an oscillator, a plurality of D latches, a temperature coder and a counter. The voltage comparator can output a pair of steeply rising step-function signals serving as internal transmission signals of the start time and the end time; the oscillator is a delay chain circuit formed by series connection of multiple levels of door delay units, and is connected with the voltage comparator and the counter respectively. Each level of door delay unit is connected with one D latch, the time end signal output end in the voltage comparator is connected with the clock signal input ends of the D latches respectively, and the signal output ends of the D latches are connected with the input end of the temperature coder. The time test circuit works, and the delay time t is calculated through the formula t=N*n*TLSB+n1*TLSB, wherein N refers to the count value of the counter, n refers to the total level number of the door delay units in the delay chain circuit, and TLSB refers to the delay time of one door delay unit. The time test circuit and a time test method can reduce the switching time of the signals in each level of door delay unit and reduce the power consumption.

Description

technical field [0001] The invention relates to the technical field of digital circuits, in particular to a time test circuit and a time test method. Background technique [0002] With the continuous development of integrated circuit size miniaturization, high-precision time test chips have become a research hotspot. The traditional direct counting method realizes time measurement by counting the frequency of the reference clock. When the clock frequency is GHz, its time measurement accuracy It has only reached the ns level, and its accuracy is greatly limited by the frequency of the reference clock, which cannot meet higher measurement accuracy. Then a time measurement method based on delay unit was proposed. The time start signal propagates in the delay chain. When the time end signal arrives, the position where the time start signal propagates is locked. The measured time can be obtained by calculating the number of delay chains. Its accuracy depends on the delay time of...

AI Technical Summary

Problems solved by technology

The trigger signal is directly selected as the propagation signal in the delay chain, because the rising edge time of the pulse signal as the trigger signal is relatively long, and at the same time, it is mixed with interference

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