實現在28奈米製程下0.4V近臨界電壓之三態內容可定址記憶體設計

Abstract

即便三態內容可定址記憶體是個大功耗的系統晶片，但它的快速與特殊性，使它仍然被廣泛地應用於IP位置搜尋功能上與快取記憶體中。隨著穿戴式裝置的發展與物聯網的興起，低功率消耗、低操作電壓逐漸成為現今系統晶片設計的主流，若要將三態內容可定址記憶體應用於未來發展的物聯網產品中，它首先要克服的就是大功耗問題，但在先進製程中，傳統6T架構的靜態隨機存取記憶體的讀寫能力會因製程變異而嚴重退化，使其無法在低操作電壓下運作。本篇論文使用聯電28奈米高介電係數金屬閘極半導體製程，並將記憶體迷你陣列架構應用於三態內容可定址記憶體中，大幅地降低電路的操作電壓，將其降到0.4V。除此之外，我們還在設計中加入階層式預充電電路、電源控制和漣波比較傳輸架構來讓整體的功耗能再降低。

Even though ternary content addressable (TCAM) is the power hungry circuitry, it still be extensively adopted in routing table of network systems by its high speed and unique. With the develop of the portable devices and the rise of Internet of Things (IoT), the issue of energy efficiency and low supply voltage become a major trend in SoC. If we want to introduce TCAM into IoT. Its power hungry problem should be solved first. However, conventional 6T SRAM is hard to work in low supply voltage duo to read/write ability degradation which caused by severely process variation in advance process. We realize our design in umc 28nm high-k metal-gate (HKMG) CMOS technology. We introduce the 6T Mini-array into TCAM and let it can even operate at 0.4V. Additionally, we use hierarchical PRE, power gating and ripple search-line in our design which let total energy consumption less.