200807440 九、發明說明： 【發明所屬之技術領域】 本發明是有關於一種搜尋電路，且特別是有關於一種 可應用於内容可定址記憶體之分段式搜尋線電路裝置。 【先前技術】 低功率電路設計在積體電路（IC)中扮演者童要的角 色，所以低耗電量也成為覌今積體電路（IC)不可或缺的特 性之一。尤其在記憶體電路（Mem〇ry 中，因電晶 體所佔數目極龐大，所以在設計記憶體時，功率消耗之考 慮是極重要的性能指標。而隨著網路通訊速竄起，再加上 IPv6的推動，内容可定址記憶體（c〇ntent AddressableBACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a search circuit, and more particularly to a segmented search line circuit device that can be applied to content addressable memory. [Prior Art] Low-power circuit design plays a role in the integrated circuit (IC), so low power consumption has become one of the indispensable characteristics of today's integrated circuits (ICs). Especially in memory circuits (Mem〇ry, because the number of transistors is extremely large, the consideration of power consumption is a very important performance indicator when designing memory. And with the speed of network communication, plus Promoted by IPv6, content can be addressed to memory (c〇ntent Addressable)
Memory : CAM)的效能已成為高速度與低功率網路晶片性 能的重要依據。而在内容可定址記憶體的研究中，為了降 低使用成本與提高使用效益，比對線（Match line)的效 能以及功率消耗的改善是極力改善的目標之一，據此，近 年來的研究領域中，已經能將比對線（Match Hne)的功 率消耗降到相當低的比例，所以，内容可定址記憶體（CAM) 的功率消耗絕大部分都落在搜尋線（Search丨ine)上。 參照第1圖，一種現有解決搜尋線（Search Hne) 上功率消耗的方法是將比對線（Match〗ine )切管線，使 其區分為一第一區101與一第二區1〇2,其中1〇3是一全 域搜哥驅動器（Global search driver)，104為一區域搜尋 驅動器（Local search driver);利用前一級（即該第一區101) 5 200807440 比對的結果’控制下—級（即該第二1⑽）的搜尋線是否 作搜哥的動作，其中，因該第二區102是受該第一區1〇1 =對結果所控制，若該第一區1〇1比對結果只要有一筆吻 合，則該區域搜尋驅動器1〇4會將全域搜尋線1〇5(Gl〇bai 化訂比Une)的資料送進區域搜尋線106 ( Local search )。相 的，右該第一區1〇1比對結果均不吻合，則該區域搜尋 二104不會將整體搜尋線1〇5(Gi〇bai sarch line)的資料送 進區域拽尋線1〇6 (L〇cal search)，以減少充放電的功率 消耗。 但是，此種方式會增加許多數量的暫存器與控制邏輯 閘（例如· OR Gate)，不僅會增、加功率消耗，且會影響到比 對線（Match 1 ine )的效能。此外，因管線的設計，讓比 對結果無法在一個週期（吖〇16)内取得，使應用在内容可 疋址記憶體（CAM)此系統時，必須特別注意時序控制的問 題’否則整體效能相對減低。 參照第2圖，另一種現有解決搜尋線（Search Hne) 上功率消耗的方式，是採用電荷再利用的技巧。第2圖中 2们表示搜尋線（SBLP、SBLN)上的負載電容。當外部 資料輸入至一控制電路201時，該控制電路2〇1將檢查輸 入的資料是否與搜尋線（SBLP、SBLN)上的資料相同， 若資料不相同，則該控制電路201驅動一傳輸閘2〇2，讓 搜尋線（SBLP、SBLN )兩侧的電位經由該傳輸閘2〇2調 整一致。當搜尋線（SBLP、SBLN )兩側的電位一致後， «亥傳輸閘202關閉’且該控制電路201將資料送至搜尋線 6 200807440 (SBLP、SBLN )上，藉迚蕾斗八> l、 此電何为旱的機制，讓搜尋線 (SBLP、SBLN)因亦放雪於、ώ 死敌電所浪費掉的電荷減少，藉以達 到節省功率的效用。 然而，利用此種解決搜尋線上功率消耗的機制，因搜 哥線上的負載電容203的電容佶fr p 电谷值（clp、CLN)相當大，雖 可達到節省功率的作用’但卻造成需要額外增設控制電路 2〇1 ’並且將即省的功率部分轉嫁至控制電路加上，整 體而言，消耗功率並未有效地降低。 歸納上述，現有的電路為了節省搜尋線上的功率，皆 需付出額㈣功率在其增加的㈣電路，甚至f彡響到比對 線的效能。 L贫明内容 因此本發明的目的就是在提供—種可應用於内容The performance of Memory : CAM has become an important basis for high speed and low power network chip performance. In the research of content addressable memory, in order to reduce the cost of use and improve the use efficiency, the improvement of the performance of the Match line and the improvement of power consumption are one of the goals of improvement, and accordingly, the research field in recent years. In this case, the power consumption of the Match Hne has been reduced to a relatively low ratio, so most of the power consumption of the Content Addressable Memory (CAM) falls on the search line (Search丨ine). Referring to FIG. 1, an existing method for solving power consumption on a search line (Search Hne) is to cut a pipeline (Match) to distinguish it into a first area 101 and a second area 1〇2. 1〇3 is a global search driver, 104 is a local search driver; using the previous level (ie, the first area 101) 5 200807440 the result of the comparison 'control under the level (ie, whether the search line of the second 1 (10)) is a search operation, wherein the second area 102 is controlled by the first area 1 〇 1 = the result, if the first area 1 〇 1 is aligned As a result, as long as there is a match, the area search driver 1〇4 sends the data of the global search line 1〇5 (Gl〇bai order ratio Une) to the area search line 106 (Local search). If the comparison between the first and the first regions of the first region is not consistent, then the region search for the second 104 will not send the data of the overall search line 1〇5 (Gi〇bai sarch line) into the region 拽 线 1〇 6 (L〇cal search) to reduce the power consumption of charge and discharge. However, this method will increase the number of registers and control logic gates (such as · OR Gate), which will not only increase the power consumption, but also affect the performance of Match 1 ine. In addition, due to the design of the pipeline, the comparison result cannot be obtained in one cycle (吖〇16), so when applying to the system of content addressable memory (CAM), special attention must be paid to the problem of timing control. Relatively reduced. Referring to Fig. 2, another conventional solution to the power consumption on the search line (Search Hne) is to use charge reuse techniques. In Figure 2, 2 shows the load capacitance on the search lines (SBLP, SBLN). When the external data is input to a control circuit 201, the control circuit 2〇1 checks whether the input data is the same as the data on the search lines (SBLP, SBLN). If the data is different, the control circuit 201 drives a transmission gate. 2〇2, the potentials on both sides of the search line (SBLP, SBLN) are adjusted by the transfer gate 2〇2. When the potentials on both sides of the search line (SBLP, SBLN) match, the «Hai transmission gate 202 is closed' and the control circuit 201 sends the data to the search line 6 200807440 (SBLP, SBLN), by the 迚 斗斗八> The mechanism of this electricity is a drought, so that the search line (SBLP, SBLN) can reduce the amount of charge that is wasted by the snow and the dead enemy electricity, so as to achieve the power saving effect. However, by using this mechanism to solve the online power consumption, the capacitance 佶fr p electric valley (clp, CLN) of the load capacitance 203 on the search line is quite large, although the power saving effect can be achieved, but it requires additional The control circuit 2〇1' is added and the power portion that is saved is passed on to the control circuit. Overall, the power consumption is not effectively reduced. In summary, in order to save the power on the search line, the existing circuit has to pay (4) the power in its increased (four) circuit, and even f to the performance of the comparison line. L-poor content, therefore, the object of the present invention is to provide a kind of content that can be applied to
=址記《之分段式搜尋㈣路裝置，用轉決 線上功率消耗的方法， 改善採用比對線切管線的方式， 增加大量暫存器盥控制羅 从…、控制璉軏閘，以及時序控制無法在一 週期取仔的缺點。 因此本發明# s 目的^在提供—種可應用於 搜尋線上功率消耗的:^搜讀電路裝置’用以解決現 、、，改善採用電荷再利用的方式 必須增加控制電路，祐 、’使功率消耗在其增加的控制電 ，進而衫響比對線的效能的缺點。 W康本^明之上述目的，提出―種可應用於内容可 200807440 址記憶體之分段式搜尋線電路裝置，是採加入一分段單元 將搜尋線分成數段，加入的電路裝置具有自動控制之功 能’且無需更改搜尋線驅動器的電路。 依照本發明一較佳實施例，該内容可定址記憶體具有 多數個呈陣列排列的細胞元，以及多數連接在每一細胞元 之間的搜尋線，該分段單元連接在該等細胞元之間，用以 切斷該等搜尋線，將該等細胞元區分成多個節段，以達到 分段搜尋的功效，相較於現有例子採用比對線切管線的方 式，會增加大量暫存器與控制邏輯閘，及時序控制無法在 一個週期取得的缺點，以及另一種現有例子以電荷再利用 的方式，導致增加控制電路並使消耗功率轉移至控制電路 進而影響比對線效能的缺點，本發明不但無需更改搜尋線 驅動器電路，採分段搜尋以及利用自動偵測的機制，即可 克服％序問題’且不會產生額外的消耗功率。 依照本發明一較佳實施例，該分段單元具有二個分段 早元，以將邊專細胞元區分成二個節段，該等分段單元呈 有一開關電路以及一記憶電路。利用該分段單元的記憶電 路設定分段單元的開關，當記憶電路儲存Γ 〇」時，分段 單元之開關電路將被關閉，上方的搜尋線則為低準位，搜 尋線驅動器不會對此節段作充放電之動作，如此，便可降 低搜尋線的負載電容，並且達到降低搜尋線之消耗功率的 功效。 依照本發明一較佳實施例，利用該記憶電路中具有儲 存的機制’可記憶此分段單元上方的細胞元是否為不比對 8 200807440= Location "Segmented search (four) way device, using the method of switching power consumption on the line, improving the way of using the line cut pipeline, adding a large number of registers, controlling the gate, controlling the gate, and timing Control can not take the shortcomings of a cycle. Therefore, the present invention provides a kind of power consumption that can be applied to the search line: ^ search circuit device 'to solve the present, and improve the way of using charge reuse must increase the control circuit, It consumes the disadvantages of its increased control power, which in turn affects the performance of the pair. W Kangben ^ Ming's above purpose, proposed a kind of segmentation search line circuit device that can be applied to the content of 200807440 address memory, is to join a segmentation unit to divide the search line into several segments, and the added circuit device has automatic control The function ' does not need to change the circuit of the search line driver. According to a preferred embodiment of the present invention, the content addressable memory has a plurality of cell elements arranged in an array, and a plurality of search lines connected between each cell element, the segment unit being connected to the cell elements In order to cut off the search lines, the cells are divided into a plurality of segments to achieve the effect of segmentation search. Compared with the existing example, the method of comparing the line-cut pipelines increases the amount of temporary storage. And the control logic gate, and the shortcomings that timing control can not be achieved in one cycle, and another existing example in the form of charge reuse, resulting in the addition of control circuitry and the transfer of power to the control circuit to affect the performance of the comparison line performance, The invention not only does not need to change the search line driver circuit, but also uses the segmentation search and the mechanism of automatic detection to overcome the % sequence problem' without generating additional power consumption. In accordance with a preferred embodiment of the present invention, the segmentation unit has two segmentation early elements to divide the edge-specific cell elements into two segments, the segmentation cells having a switching circuit and a memory circuit. The memory circuit of the segmentation unit is used to set the switch of the segmentation unit. When the memory circuit stores Γ", the switch circuit of the segmentation unit will be turned off, and the upper search line is at a low level, and the search line driver will not be right. This segment acts as a charge and discharge, thus reducing the load capacitance of the search line and reducing the power consumption of the search line. According to a preferred embodiment of the present invention, the mechanism of storing in the memory circuit can be used to memorize whether the cell elements above the segmentation unit are incomparable. 8 200807440
狀態’在寫入動作時’寫人的資料若為不比對狀綠，則寫 入位元線（WBLP、W關皆為高準位，資料^便存人 記憶電路，分段單元的開關電路將被_，搜尋線上的次 料便無法通過。相反的，當存人的資料是比對狀態，則二 條寫入位a線中（WBLP、WBLN)必會有—條為高準位，一 條為低準位，資料⑴便存人記憶電路，分段單元的開 關電路將被打開，搜尋線上的資料得以通過，藉此，依據 内容可定址記憶體儲存資料之不同，分段單Μ的記憶電 路可自動調整關閉，以賴尋線的消耗功率達到最佳化 態。 根據上述，可知本發明之可應用於内容可定址記憶體 之分段式搜尋線電路裝置確實具有下列優點： 1. 採以分段式搜尋線，無須更改搜尋線驅動器的電 路，具有自動_機制’不會產生額外的消耗功率。 2. 利用分段單元關閉細胞元的搜尋線節段，以減少搜 号線驅動器的負載電容，進而達到降低消耗功率的功效。 【實施方式】 參照第4圖，是本發明的—較佳實施例的示意圖。 本發明之可應用於内容可定址記憶體之分段式搜尋 線電路裝置的較佳實施例，包含一内容可定址記憶體 鳩、兩個群㈣分段單元佩及—比對線電路则（胸d he，該比對線轉_為習知技術，不再贅述）。 該内容可定址記憶體3〇〇具有多數個呈陣列排列的細 200807440 胞元310、多數連接在每一細胞元310(Cell)之間的搜尋線 320，以及一個搜尋驅動單元，該搜尋驅動單元具有多數 個搜尋線驅動器330。 第3圖說明内容可定址記憶體300 ( CAM )的儲存資 料（Routing table)，該等細胞元310中，所儲存的資料分 為「0」、「1」以及「X」，「〇」表示Low狀態，「1」表示 Hi狀態’而「X」表示不比對（Don’t care)。而儲存「X」 的該等細胞元310並不會與該等搜尋線32〇上的資料做比 對’所以搜哥線320的資料對於Don’t care的細胞元 310(Cell)並無影響，因此，本發明藉此特性提出分段式的 搜尋線320 ’利用關閉具有「X」Don’t care的細胞元310 (Cell )的搜尋線節段，可以減少搜尋線驅動器33〇的負 載電容。 參照第4圖，該分段單元400電連接在該等細胞元31〇 之間，用以切斷該等搜尋線320，將該等細胞元31〇區分 成多個卽段’以作分段搜哥。在本實施例中，設有兩個群 組的分段單元400、400,，以將該等細胞元31〇區分成三 個卽#又301、302及303。該等分段單元4〇〇、400’與該等 細胞元310之間呈陣列排列，其中該分段單元400包括所 有的「㊉」符號，該分段單元400,包括所有的「0」符號。 該分段單元400内含一個受控制的開關（該開關是指 第5圖的開關電路420，容後詳述），開關的控制來自於其 上輸入端中的細胞元310。若分段單元4〇〇，之上的細胞元 31〇儲存資料為「X」Don’t care(不比對），資料就無須被 200807440 傳送到上方節段的搜尋線320，（第4圖虛線所示的搜尋線 3 2 〇 ’）’則分段單元4 〇 〇内的開關被打開（『Θ』：開路叩e n』。 相反的，若分段單元400之上的細胞元31〇儲存為非D〇n，t care(比對狀態），資料就必須被傳送到上方節段的搜尋線 320 (第4圖實線所示的搜尋線32〇)，肖分段單元柳内 的開關會被關閉（「㊉」：閉路close)。當分段單元41〇，之 開關打開時，開關下方的搜尋線32〇的資料就無法傳送到 上方之搜尋線320’，因為搜尋線驅動器33〇所需充放電的 搜尋線節段減少，所以也節省了功率消耗，進而達到降低 功率消耗的功效。 參照第5圖，該等分段單元4〇〇具有一開關電路42〇, 以及一記憶電路430。 參照第6圖，該開關電路42〇具有二傳輸閘 421 (Transmission gate)，以及二 N 型電晶體 422。該等 n 型電晶體422是一個N型金屬氧化半導體（]^〇8)電晶體。 。亥專N型電曰曰體422的閘極G與、;及極D分別接設於該等 傳輸閘421，該等ν型電晶體422的源極S接地。 參照第7圖’該記憶電路430具有五個電晶體431、 一個邏輯閘432、一個反向器433，以及一個傳輸閘434。 該等電晶體431均為場效電晶體，該邏輯閘432是一反及 閘（NAND) 〇 參照第4、5、6圖，至於該開關電路420的運作情形： 首先’ q與qn乃互補的訊號，當q為低準位（Low )時， 該開關電路420中的傳輸閘421被打開，而該關關電路42〇 11 200807440 上方的搜尋線（SBLPu'SBLNu)均透過電晶體422而設 為低準位，如此上方搜尋線（見第4圖的32〇。的節段即被 關閉，搜尋線驅動器330並不會對此節段作充放電之動 作口此其負載便可降低，消耗功率也隨之將降低。 參第5、6、7圖，當q為高準位（m)時，該開關 電路420中的傳輸閘421關閉（cl〇se ••閉路），此時外部 輸入之資料可透過該該關關電路42〇傳送至上方搜尋線 320供該等細胞元31〇做比對的動作，且該開關電路*川 受到該記憶電路430所控制，該記憶電路43〇具有儲存機 制，可記憶上方之細胞元310(見第5圖）的資料是否為 D〇n’tcare。在内容可定址記憶體（CAM)為寫入動作時， 若寫入於細胞元310的資料為Don，t care，則寫入位元線 (WBLP、WBLN )均為高準位，此時，將此資料存入於該 記憶電路430，故該記憶電路430中q為低準位，隨即打 開該開關電路420中的傳輸閘421 (open :開路），搜尋線 320的資料便無法通過。相反的，當儲存至細胞元的 貢料非Don’t care時，則該記憶電路430中的q則為高準 位，此該開關電路420中的傳輸閘421關閉（close:閉路）， 搜尋線320的資料得以通過。 據上所述，本發明透過分段式搜尋線電路，搜尋線驅 動器的負載得以降低，且依照内容可定址記憶體（cam) 儲存資料不同，分段單元400、400,會自動調整開關電路， 讓搜尋線320’的功率消耗處於最佳化狀態。而且使用此電 路裝置，搜尋線驅動器330之電路並不需做修改，在電路 12 200807440 實現上相當容易。參閱第 圖，而且該分段單元400 :、，、田胞70 31G、該比對線電路_的尺寸—致，即可以 併貼方式佈局於整個記憶體陣列中。 根據上述，本發明之可應用於内容可定址記 段式搜尋線電路裝置具有下列優點： 之刀 1.本發明採时段式的搜尋線，姻更改搜尋線驅動 器33〇的電路，並具有自動_機制，所以不會產生額外When the status 'when writing' is written, the data of the writer is not more than the green of the pair, then the bit line is written (WBLP, W are all high level, the data ^ is stored in the memory circuit, the switching circuit of the segment unit Will be _, the secondary line on the search line will not pass. Conversely, when the stored data is in the comparison state, the two write bits in the a line (WBLP, WBLN) must have a high level, one For the low level, the data (1) will be stored in the memory circuit, the switching circuit of the segmentation unit will be turned on, and the data on the search line will be passed, thereby, according to the content of the addressable memory storage data, the segmentation of the memory The circuit can be automatically adjusted and turned off to optimize the power consumption of the homing line. According to the above, it can be seen that the segmented search line circuit device applicable to the content addressable memory of the present invention has the following advantages: With the segmented search line, there is no need to change the circuit of the search line driver, and the automatic_mechanism does not generate additional power consumption. 2. Use the segmentation unit to turn off the search line segment of the cell to reduce the search line driver. The present invention is a schematic diagram of a preferred embodiment of the present invention. The present invention is applicable to a segmented search line circuit for content addressable memory. A preferred embodiment of the device includes a content addressable memory 两个, two groups (four) segmentation unit, and a comparison line circuit (thoracic d he, the comparison line _ is a conventional technique, and is not described again. The content addressable memory 3 has a plurality of thin 200807440 cells 310 arranged in an array, a plurality of search lines 320 connected between each cell 310 (Cell), and a search driving unit, the search The driving unit has a plurality of search line drivers 330. Fig. 3 illustrates a Routing table of content addressable memory 300 (CAM), in which the stored data is divided into "0" and "1". And "X", "〇" indicates the Low state, "1" indicates the Hi state and "X" indicates the Don't care. The cells 310 storing the "X" do not Wait for the information on the search line 32〇 The data of the Sogou line 320 has no effect on the cell element 310 (Cell) of the Don't care. Therefore, the present invention proposes a segmented search line 320' by means of the feature "X" Don't The search line segment of the cell element 310 (Cell) of the care can reduce the load capacitance of the search line driver 33. Referring to Fig. 4, the segmentation unit 400 is electrically connected between the cell elements 31〇 for cutting Breaking the search lines 320, and dividing the cell elements 31 into a plurality of segments' for segmentation. In this embodiment, two groups of segmentation units 400, 400 are provided, These cell elements 31 are divided into three 卽# 301, 302 and 303. The segmentation units 4A, 400' are arranged in an array with the cell elements 310, wherein the segmentation unit 400 includes all "ten" symbols, and the segmentation unit 400 includes all "0" symbols. . The segmentation unit 400 contains a controlled switch (referred to as the switch circuit 420 of Figure 5, as detailed later), the control of which is derived from the cell 310 in its upper input. If the segmentation unit 4〇〇, the cell element 31〇 above stores the data as “X” Don't care, the data does not need to be transmitted to the search line 320 of the upper segment by 200807440 (the dotted line of Fig. 4) The search line 3 2 〇 ')' is shown, and the switch in the segment unit 4 is opened ("Θ": open circuit 叩en". Conversely, if the cell element 31 above the segment unit 400 is stored as For non-D〇n, t care (alignment state), the data must be transmitted to the search line 320 of the upper segment (the search line 32〇 shown by the solid line in Fig. 4). Closed ("Ten": closed circuit close). When the segment unit 41〇, the switch is turned on, the data of the search line 32〇 under the switch cannot be transmitted to the upper search line 320' because the search line driver 33 The search line segment to be charged and discharged is reduced, so power consumption is also saved, thereby achieving the effect of reducing power consumption. Referring to FIG. 5, the segmentation unit 4A has a switch circuit 42A, and a memory circuit 430. Referring to FIG. 6, the switch circuit 42A has two transfer gates 421 ( Transmission gate), and two N-type transistors 422. The n-type transistors 422 are an N-type metal oxide semiconductor (?) 8) transistor. The gate G of the N-type electric body 422 And the poles D are respectively connected to the transmission gates 421, and the source S of the ν-type transistors 422 is grounded. Referring to FIG. 7 'the memory circuit 430 has five transistors 431, one logic gate 432, one The inverter 433, and a transmission gate 434. The transistors 431 are field effect transistors, and the logic gate 432 is a NAND gate. Referring to Figures 4, 5 and 6, the switch circuit 420 is used. Operational situation: First, 'q and qn are complementary signals. When q is low level (Low), the transmission gate 421 in the switch circuit 420 is turned on, and the search line above the shut-off circuit 42〇11 200807440 (SBLPu'SBLNu) is set to a low level through the transistor 422, so that the upper search line (see 32〇 of Fig. 4 is closed), and the search line driver 330 does not charge or discharge the segment. The load can be reduced and the power consumption will be reduced. See Figures 5, 6, and 7, When q is at a high level (m), the transfer gate 421 in the switch circuit 420 is turned off (cl〇se ••closed circuit), and the externally input data can be transmitted to the upper search line 320 through the off circuit 42〇. For the cell elements 31, the switching circuit is controlled by the memory circuit 430, and the memory circuit 43 has a storage mechanism for memorizing the cell element 310 above (see FIG. 5). Whether the data is D〇n'tcare. When the content addressable memory (CAM) is a write operation, if the data written in the cell 310 is Don, t care, the write bit lines (WBLP, WBLN) are all at a high level. The data is stored in the memory circuit 430. Therefore, q in the memory circuit 430 is at a low level, and then the transfer gate 421 (open: open circuit) in the switch circuit 420 is turned on, and the data of the search line 320 cannot pass. Conversely, when the tribute stored in the cell element is not Don't care, the q in the memory circuit 430 is at a high level, and the transfer gate 421 in the switch circuit 420 is turned off (close: closed circuit), searching The data of line 320 was passed. According to the above, the segmentation search line circuit can reduce the load of the search line driver, and the segmentation unit 400, 400 automatically adjusts the switch circuit according to the content of the content addressable memory (cam). The power consumption of the search line 320' is optimized. Moreover, with this circuit arrangement, the circuit of the search line driver 330 does not need to be modified, and is quite easy to implement in circuit 12 200807440. Referring to the figure, and the segmentation unit 400:,,, the cell 70 31G, the size of the comparison line circuit _, can be laid out in the entire memory array. According to the above, the present invention is applicable to a content addressable segment type search line circuit device having the following advantages: 1. The tool of the present invention adopts a search line of a time-lapse type, and the circuit of the search line driver 33〇 is modified and has an automatic_ Mechanism, so it won't generate extra
的消耗功率。 * 2.本發明制該分段單元彻關閉該等細胞元310的 搜尋線節段，以減少搜尋線驅動器33G的負载電容，進而 達到降低消耗功率的功效。 3.本發明的該分段單元4〇〇與該細胞元 310、該比對 線電路5⑽的尺寸-致，即可以併貼方式佈局於整個記憶 體陣列中，使實施上更加容易。 更值得一提的是，本發明可應用於内容可定址記憶體 之分段式搜尋線電路裝置具有低消耗功率、高搜尋速度的 優點，於應用上，可以增進網路路由器、硬體搜尋引擎、 樣本比對器等應用之性能，以提高產業運用之好處。 雖然本發明已以一較佳實施例揭露如上，然其並非用 以限定本發明，任何熟習此技藝者，在不脫離本發明之精 神和範圍内，當可作各種之更動與潤飾，因此本發明之保 護範圍當視後附之申請專利範圍所界定者為準。 圖式簡單說明】 13 200807440 為讓本發明之上述和其他目的、特徵、優點與實施例 能更明顯易懂，所附圖式之詳細說明如下： 第1圖是現有内容可定址記憶體之利用比對線切管線 的搜尋電路之線路圖。 第2圖是現有内容可定址記憶體之運用電荷再利用的 搜尋電路之線路圖。 第3圖是緣示本發明一較佳實施例的可應用於内容可 定址記憶體之分段式搜尋線電路裝置之佈局示意圖。 第4圖是繪示本發明該較佳實施例的分段式搜尋線電 路裝置的分段線之佈局示意圖。 第5圖是繪示本發明該較佳實施例的分段單元的方塊 路。 第6圖是繪示第5圖之開關電路的電路圖。 第7圖疋緣示第5圖之記憶電路的電路圖。 第8圖是繪示第4圖中部份的電路圖。 第9圖疋繪不依照第8圖實施於電路佈局中之併貼狀 態的佈局圖。 【主要元件符號說明】 1〇1 :細胞元第一區 1〇3 :全域搜尋驅動器 102 :細胞元第二區 104 :區域搜尋驅動器 14 200807440 105 ： 全域搜尋線 106 ： 區域搜尋線 201 ： 控制電路 202 ： 傳輸閘 203 : 電容 300 ： 内容可定址記憶體 301 ： 節段 302 ： 節段 303 ： 節段 310 ： 細胞元 320 ： 搜尋線 330 ： 搜尋線驅動器 320, :搜尋線 400 ： 分段單元 420 ： 開關電路 421 : 傳輸閘 .' 430 ： 記憶電路 422 *： N型電晶體 432 ： 邏輯閘 431 ： 電晶體 434 ： 傳輸閘 433 ： 反向器 500 ： 比對線電路 15Power consumption. * 2. The segmentation unit of the present invention completely closes the search line segments of the cell elements 310 to reduce the load capacitance of the search line driver 33G, thereby achieving the effect of reducing power consumption. 3. The segmentation unit 4 of the present invention is dimensioned with the cell element 310 and the comparison line circuit 5 (10) so that it can be placed in the entire memory array in a manner that is easier to implement. It is worth mentioning that the segmented search line circuit device applicable to the content addressable memory has the advantages of low power consumption and high search speed, and can improve the network router and the hardware search engine in application. The performance of applications such as sample comparators to improve the benefits of industrial applications. Although the present invention has been described above in terms of a preferred embodiment, it is not intended to limit the invention, and it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; Compare the circuit diagram of the search circuit of the line cut pipeline. Figure 2 is a circuit diagram of a search circuit for the reuse of charge in an existing addressable memory. Figure 3 is a schematic diagram showing the layout of a segmented search line circuit device applicable to content addressable memory according to a preferred embodiment of the present invention. Fig. 4 is a view showing the layout of a segment line of the segmented search line circuit device of the preferred embodiment of the present invention. Figure 5 is a block diagram showing the segmentation unit of the preferred embodiment of the present invention. Fig. 6 is a circuit diagram showing the switching circuit of Fig. 5. Fig. 7 is a circuit diagram showing the memory circuit of Fig. 5. Figure 8 is a circuit diagram showing a portion of Figure 4. Fig. 9 is a layout diagram of a state in which the layout is not performed in accordance with Fig. 8 in the circuit layout. [Main component symbol description] 1〇1: cell first region 1〇3: global search driver 102: cell element second region 104: region search driver 14 200807440 105: global search line 106: region search line 201: control circuit 202: Transmission gate 203: Capacitor 300: Content addressable memory 301: Segment 302: Segment 303: Segment 310: Cell element 320: Search line 330: Search line driver 320, Search line 400: Segment unit 420 : Switching circuit 421 : Transmission gate. ' 430 : Memory circuit 422 *: N-type transistor 432 : Logic gate 431 : Transistor 434 : Transmission gate 433 : Inverter 500 : Comparison line circuit 15