On-chip tri-state signal detection device and detection method thereof

Abstract

The invention relates to an on-chip tristate signal detection device and a detection method thereof. The detection device includes a first current source, a second current source, a first switch, a second switch, a threshold comparison unit, and a digital control unit. The first current source is connected to the first end of the first switch, the second end of the first switch is connected to the first end of the second switch, and the second end of the second switch is connected to the second current source. The digital control unit controls the closing and / or opening of the first switch, the second switch to form two different topological structures. Based on one of the topologies, the threshold comparison unit first input receives a voltage associated with a tri-state input signal. The second input terminal of the threshold comparison unit receives a reference voltage, and compares the magnitude relationship between the relevant voltage and the reference voltage, so that the digital control unit can detect the state of the input signal based on the comparison result. The invention has low detection power consumption and high reliability of detection results, and can be widely used in the field of on-chip detection of chip interface signals.

Description

technical field [0001] The invention relates to the field of digital integrated circuits, in particular to the field of chip interface signal detection. Background technique [0002] The tri-state signal (Tri-State or T / S) includes three signal states of high level, low level, and high-impedance state (also known as forbidden state). Devices with these three signal states are called tri-state gates. [0003] In chip input control, tri-state signals are usually used to control chip pins to achieve more configurable states, so that pin resources with a limited number of chips can be used more effectively. At present, the three-state signal detection method is usually to connect the signal to be tested to the internal node of the high-resistance resistor string between the power supply and the ground, by comparing the voltage values ​​of other nodes in the high-resistance resistor string, and according to different detection The results are combined to enable identification o...

AI Technical Summary

Problems solved by technology

[0004] This detection of the tri-state signal by detecting the internal voltage of the high-resistance resistor string will directly lead to two more prominent problems: 1. The on-chip high-resistance resistor string will consume considerable chip area or generate large static power. Current consumption; 2. This detection method has a large limit on the range of input voltage, and it is difficult to cover digital integrated circuits under different production processes.

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