Ternary Content Addressable Memory Unit Capable Of Reducing Charge Sharing Effect

Abstract

A ternary content addressable memory unit includes a first inverter, a second inverter, a third inverter, a fourth inverter, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, and an eighth transistor. The first inverter includes an input terminal, and an output terminal coupled to a first node. The second inverter includes an input terminal coupled to the first node and an output terminal coupled to the input terminal of the first inverter. The third inverter includes an input terminal coupled to a second node and an output terminal. The fourth inverter includes an input terminal coupled to the output terminal of the third inverter and an output terminal coupled to the second node.

Description

BACKGROUND OF THE INVENTION1. Field of the Invention[0001]The present invention is related to a ternary content addressable memory (TCAM) unit, and more particularly to a ternary content addressable memory unit capable of reducing charge sharing effect.2. Description of the Prior Art[0002]When performing digital data operations, the large amount of data needs to be processed. The stored data of some applications (such as network routers) needs to be updated dynamically, and the stored data cannot be sorted in advance. It is difficult to achieve instant data query. In order to effectively speed up searching large random data, content addressable memory (CAM) is adopted to solve various searching problems. Content addressable memory is like a huge lookup table. It can find the address of the matching keyword based on the input keyword. The architecture of CAM allows the keyword to be searched to be compared with the data stored in the CAM at the same time, and outputs the data address...

AI Technical Summary

Benefits of technology

This configuration effectively reduces matching errors caused by charge sharing, while also simplifying the circuit design and reducing manufacturing costs by minimizing the number of required metal layers.

Problems solved by technology

The stored data of some applications (such as network routers) needs to be updated dynamically, and the stored data cannot be sorted in advance.

It is difficult to achieve instant data query.

There is a voltage charge sharing problem between the nodes of conventional ternary content addressable memory.

If there is charge sharing between the nodes during evaluation phase of the memory operation, it may cause the node voltage to drop to a sufficiently low voltage so the output inverter would have a matching error.

Images