由於平行比對使得Content addressable memory (CAM)有快速的資料搜尋速度。因此Content addressable memory (CAM)被廣泛的應用在很多方面，例如：asynchronous transfer mode (ATM), communication networks, LAN bridges/switches , databases, lookup table , and tag directories in fully associative cache systems。然而平行比對總是消耗較多功率的。於是本篇論文提出了一個Gate-Block-Section Algorithm。此方法以Precomputation-Based Content Addressable Memory(PB-CAM)架構為基礎，透過gate block的選擇來減少平行比對次數。依據程式模擬的結果，本篇論文的方法可以減少19.0%~26.6%的平行比對次數。在實驗過程中，使用TSMC 0.18μm，1.8V。為求精準，本論文使用Synopsys Nanosim量測功率。由實驗結果顯示，本篇論文的方法可以節省3.1%~13.3%的功率。這篇文章主要的目的是提供理論和實際的證據驗證Gate-Block-Selection Algorithm可以進一步針對不同的benchmark節省功率。因此我們的Gate-Block-Selection Algorithm非常適用於嵌入式系統。

Content addressable memory (CAM) is a major device in asynchronous transfer mode
(ATM), communication networks, LAN bridges/switches , databases, lookup table ,
and tag directories in fully associative cache systems, due to its high-speed parallel
data searching operation. Hence, the operation of CAM requires an enormous number
of comparison operations. Obviously, these comparison operations consumes a large
amount of power.
In this paper, we propose a Gate-Block-Selection algorithm to construct a low
power PB-CAM to reduce the comparison operation number. By our theoretical
analysis, we can reduce 19.0 % at least, 26.6 % at most. the total number of the
comparison operation of our Gate-Block-Selection algorithm is much less than that
of the Block-XOR approach. Moreover, we implemented both the Block-XOR PBCAM
and our Gate-Block-Selection PB-CAM in the TSMC 0.18-μm digital CMOS
process technology and measure the power consumption by Nanosim. Compared to
Block-XOR approach, the experimental result shows that our Gate-Block-Selection
PB-CAM comsumes 3.1% at least and 13.3% at most less power than Block-XOR
does.
The major contribution of our paper is that we provided theoretical and practical
proof to verify that our gate-block-selection approach can further reduce the power
consumption to fit different benchmark. Therefore, our Gate-Block-Selection PBCAM
is very suitable for embedded systems.

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