SanDisk安全數(shù)碼卡 畢業(yè)設(shè)計(jì)(論文)外文資料翻譯.doc

畢業(yè)設(shè)計(jì)(論文)外文資料翻譯學(xué) 院： 計(jì)算機(jī)科學(xué)與工程學(xué)院 專 業(yè)： 計(jì)算機(jī)科學(xué)與技術(shù) 姓 名： 學(xué) 號(hào)： 外文出處： product manualversion 2.2document no. 80-13-00169 september (用外文寫) 附 件： 1.外文資料翻譯譯文；2.外文原文。 指導(dǎo)教師評(píng)語： 簽名： 年 月 日附件1：外文資料翻譯譯文sandisk安全數(shù)碼卡sd卡介紹這個(gè)安全數(shù)碼卡是一種基于閃存的記憶卡,被專門設(shè)計(jì)來滿足安全,生產(chǎn)能力,固有的性能和環(huán)境要求的新興的音頻和視頻的消費(fèi)者電子產(chǎn)品設(shè)備。sd卡的機(jī)制包括版權(quán)保護(hù),符合sdmi的安全標(biāo)準(zhǔn),速度更快,更高的記憶容量的能力。sd卡安全系統(tǒng)采用的相互影響新密碼認(rèn)證和“算法”,防止受到非法使用。一個(gè)不安全的訪問對(duì)與使用者的內(nèi)容也是可以利用的。sd卡的通信是基于一種先進(jìn)的九針腳接口(時(shí)鐘,命令,4xdata和xpower線)下運(yùn)作而設(shè)計(jì),在一個(gè)低電壓范圍內(nèi)。通信協(xié)議的定義是sd卡規(guī)格的一部分。sd卡主界面的常規(guī)操作支持多媒體卡。 換句話說,論述了前向兼容 多媒體卡被保存。 其實(shí)sd卡與多媒體卡的主要區(qū)別,在其初始化的過程。 sd卡規(guī)格最初是由松下電器公司、東芝公司和sandisk公司定義的。目前,規(guī)格由安全電子協(xié)會(huì)控制。sandisk sd卡被定義為和sd卡的物理規(guī)格是是兼容的sd卡接口便于整合成任何設(shè)計(jì),不論微處理器的使用。為與現(xiàn)有的控制器,兼容性sandisk sd卡提供除了以sd卡接口,交替通信協(xié)議,是基于spi的標(biāo)準(zhǔn)。當(dāng)前的sd卡提供1024億字節(jié)的內(nèi)存使用閃存芯片,設(shè)計(jì)了特別是用于大容量存儲(chǔ)的應(yīng)用。sd總線接口閃存模塊sandisk單芯片控制器數(shù)據(jù)輸入輸出控制 圖1-1 sd卡的塊圖表1.1 范圍本文檔描述了關(guān)鍵特征和規(guī)格的sd卡,以及所需的本產(chǎn)品主機(jī)接口系統(tǒng)的信息。1.2 產(chǎn)品模型sd卡的型號(hào)和容量如表1 - 1所示。型號(hào)容量sdsdb-1616mbsdsdj-3232 mbsdsdj-6464 mbsdsdj-128128 mbsdsdj-256256 mbsdsdj-512512mbsdsdj-10241024 mbsdsdj-20482048 mb表1-11.3 系統(tǒng)特征sd卡提供了以下特點(diǎn):.2gb的存儲(chǔ)容量.sd卡協(xié)議兼容的協(xié)議.支持spi模式.針對(duì)便攜式和固定 (版權(quán)保護(hù)申請(qǐng)擔(dān)保)和不安全的數(shù)據(jù)存儲(chǔ)。電壓范圍: .(cmd0 -基本通信,cmd15 acmd41,cmd55):2.0-3.6v,。.其他指令和記憶訪問:2.7-3.6v。.時(shí)鐘的速度0-25 ?變量兆赫。.多達(dá)25個(gè)萬位/秒的數(shù)據(jù)傳輸速率(使用4個(gè)并行數(shù)據(jù)線)。.最大的數(shù)據(jù)率多達(dá)10卡。.修正的錯(cuò)誤記憶領(lǐng)域。.保護(hù)機(jī)制版權(quán)支持最高的sdmi標(biāo)準(zhǔn).卡的密碼協(xié)議(非所有模型)。.寫保護(hù)功能使用機(jī)械的開關(guān)。.寫保護(hù)特征(內(nèi)置臨時(shí)和永久性)。.探測(cè)(卡插入/遷移)。.應(yīng)用程序特有的命令。.舒適的擦除機(jī)制。表1 - 2描述通信信道的性能表1-2sd卡的sd總線sd的spi總線六根寫通信總線三根連續(xù)的寫數(shù)據(jù)總線錯(cuò)誤保護(hù)數(shù)據(jù)轉(zhuǎn)換可選擇的不受保護(hù)的數(shù)據(jù)轉(zhuǎn)換可用模式單一的或多個(gè)定向轉(zhuǎn)換但一個(gè)或多個(gè)定向轉(zhuǎn)換1.4 sd卡標(biāo)準(zhǔn)sd卡是完全相容于下列的sd卡實(shí)體層的規(guī)格標(biāo)準(zhǔn):實(shí)體層的sd卡的系統(tǒng)規(guī)格說明1.10版本可以從以下方式的到規(guī)格說明書：sd卡協(xié)會(huì)53 muckelemi st.郵政信箱189san juan bautista,95045-0189美國(guó)電話:831-623-2107 傳真:831-623-2248 電子郵件: 1.5 功能描述sd卡sandisk含有高標(biāo)準(zhǔn)、智能子系統(tǒng)如圖1 1這個(gè)智能的(處理器)子系統(tǒng)提供了很多其它類型的記憶卡不具備的能力。這些功能包括:從細(xì)節(jié)獨(dú)立主機(jī)擦除和編程閃存。復(fù)雜的系統(tǒng)管理缺陷(很類似系統(tǒng)發(fā)現(xiàn)在磁盤驅(qū)動(dòng)器)。復(fù)雜的系統(tǒng)為差錯(cuò)恢復(fù)包括一個(gè)強(qiáng)大的糾錯(cuò)碼(ecc)。對(duì)于低功率電源管理操作。1.5.1 閃存技術(shù)獨(dú)立在一個(gè)ide磁盤驅(qū)動(dòng)器中，512字節(jié)的sd卡的扇區(qū)的大小都是一樣的。為了寫或讀一個(gè)區(qū)域(或多個(gè)領(lǐng)域),主機(jī)軟件簡(jiǎn)單的確保sd卡讀或?qū)懨?。這命令包含地址。主機(jī)軟件然后等待他們的命令去完成。主機(jī)軟件不會(huì)涉及快閃記憶體細(xì)節(jié)的擦除,編程或讀取信息。在未來的這是極其重要的作為閃光裝置將會(huì)變的越來越復(fù)雜。由于sd卡使用一個(gè)智能的車載控制器、宿主系統(tǒng)軟件不需要改變,新的快閃記憶體為基礎(chǔ)。在其他支持的話,系統(tǒng)的sd卡今天就可以使用未來sandisk sd卡一起建造新的閃光技術(shù)而無需修改或改變主機(jī)軟件。1.5.2 缺陷和錯(cuò)誤管理sd卡都包括一個(gè)復(fù)雜的缺陷和錯(cuò)誤的管理體系。該系統(tǒng)是類似于系統(tǒng)發(fā)現(xiàn)在磁盤驅(qū)動(dòng)器和在許多情況下提供改進(jìn)。例如,磁盤驅(qū)動(dòng)器通常都不會(huì)執(zhí)行一個(gè)閱讀一個(gè)寫之后的數(shù)據(jù),因?yàn)槟菚?huì)招致執(zhí)行處罰。sd卡做下一個(gè)閱讀在邊緣寫條件來驗(yàn)證資料是否正確地寫自后。在有一個(gè)字節(jié)有缺陷的看見情況下,sd卡代替這個(gè)壞的字節(jié),外加一張位在領(lǐng)域的標(biāo)題。如果必要時(shí),sd卡甚至?xí)〈麄€(gè)領(lǐng)域,與一個(gè)備用的部門。這是完全透明的主機(jī)和不消耗任何用戶數(shù)據(jù)的空間。sd卡的軟錯(cuò)誤率規(guī)格遠(yuǎn)遠(yuǎn)超過磁盤驅(qū)動(dòng)器的規(guī)格。在極為罕見的情況下一個(gè)讀錯(cuò)誤發(fā)生時(shí),sd卡有創(chuàng)新的算法來恢復(fù)數(shù)據(jù)。這是類似于在使用磁盤驅(qū)動(dòng)，但是它更復(fù)雜了。最后一道防線是要用一個(gè)強(qiáng)大的糾錯(cuò)碼到正確的數(shù)據(jù)。如果ecc被用來恢復(fù)數(shù)據(jù),有缺陷的比特位被替換為備用,以確保他們不造成任何未來的問題。這些缺陷和錯(cuò)誤管理系統(tǒng)再加上固態(tài)建設(shè)給sd卡無與倫比的可靠性。1.5.3 版權(quán)保護(hù)詳細(xì)描述的版權(quán)保護(hù)機(jī)制及相關(guān)安全的sd卡的命令可以在sd卡安全規(guī)格文檔從sd卡協(xié)會(huì)找到。所有的sd卡安全相關(guān)的命令操作的數(shù)據(jù)傳輸模式。sdmi所定義的規(guī)范中,該數(shù)據(jù)內(nèi)容就是保存在卡是保存已加密和它通過透明的和從卡。沒有操作過的數(shù)據(jù)和沒有約束的閱讀數(shù)據(jù)在任何時(shí)間。每個(gè)資料封包聯(lián)系在一起,比如(歌曲),這是存在未受保護(hù)的記憶有一種特別的數(shù)據(jù)保存在內(nèi)存保護(hù)區(qū)域。對(duì)于任何訪問(任何讀寫或擦除命令)從/到的數(shù)據(jù),在受保護(hù)的區(qū)域。做一個(gè)認(rèn)證的程序是卡”和“之間的連接裝置,要么lcm(pc為例)或pd(移動(dòng)設(shè)備中,例如sd玩家)。1.5.4 持久性sd卡有一個(gè)持久性的sandisk規(guī)格各個(gè)部門的典型(閱讀10萬寫邏輯部門是無限的)。這一數(shù)字遠(yuǎn)遠(yuǎn)超過通常要求是什么在幾乎所有的應(yīng)用程序的sd卡。例如, sd卡的經(jīng)常使用在數(shù)字相機(jī),手機(jī),個(gè)人通信器、尋呼機(jī)和聲音錄音機(jī)將僅一小部分的總耐力的典型設(shè)備的壽命。例如,它將經(jīng)過十多年的磨損面積在sd卡上的一個(gè)文件的任何尺寸(從512個(gè)字節(jié)來嗎最大容量)被重寫,3次每小時(shí)每天八小時(shí),每一年365天。以典型的應(yīng)用中,耐力極限不是任何實(shí)際的關(guān)注廣大用戶。1.5.5 穿平wear-leveling是一種內(nèi)在的一部分使用的功能,消除池nand sd記憶。sd卡的支持穿一級(jí)命令操作維護(hù)作為nop向后兼容性與現(xiàn)有的軟件公用事業(yè)。1.5.6 使用擦除指令部門或組織的擦除(的能力)指令提供了極大地增加寫性能的sd卡。一旦一個(gè)部分已經(jīng)擦除,用擦除指令部分寫給那將會(huì)快得多。這是因?yàn)橐粋€(gè)正常的寫操作,包括一個(gè)獨(dú)立的擦寫部門。1.5.7 自動(dòng)休眠模式一個(gè)獨(dú)有的特點(diǎn)的sd卡(和其它sandisk sandisk產(chǎn)品進(jìn)口和出口)是自動(dòng)進(jìn)入或退出睡眠模式。在完成后, 在5msec內(nèi)沒有收到下一步的命令sd卡將進(jìn)入睡眠模式以節(jié)約用電。為這發(fā)生主機(jī)沒有采取任何行動(dòng)。在大多數(shù)系統(tǒng),sd卡在睡眠模式,只有當(dāng)主機(jī)訪問時(shí)才被喚醒,從而節(jié)約電源。當(dāng)宿主已準(zhǔn)備好去訪問sd卡和睡眠模式,它是在發(fā)出的任何命令之后能使其退出睡眠模式并產(chǎn)生回應(yīng)。1.5.8 熱插拔主機(jī)的要求是支持熱插但要通過連接器獲得支持。連接器制造商將提供連接器產(chǎn)品,有權(quán)柄針腳的時(shí)間還不夠長(zhǎng),無法接觸前制作與動(dòng)力另一個(gè)針腳。請(qǐng)參閱連接器數(shù)據(jù)表為更多的細(xì)節(jié)。這個(gè)方法是用于pcmcia相似mmca裝置,以允許熱插入。1.5.9 sd card-sd總線模式下面的章節(jié)提供有價(jià)值的信息對(duì)sc的卡片上,裝在sd總線模式。 sd卡符合的標(biāo)準(zhǔn)sd卡是完全遵守sd卡v1.01物理層標(biāo)準(zhǔn)規(guī)格?？ㄒ?guī)格數(shù)據(jù)寄存器的構(gòu)造是服從csd1.0版本的。 談判操作條件sd卡支持的操作條件驗(yàn)證序列中定義的sd卡標(biāo)準(zhǔn)規(guī)格。sd卡主機(jī)應(yīng)該定義一個(gè)工作電壓范圍,從而不支持的sd卡將本身存在一種停滯狀態(tài),而忽視任何總線式通信。使sd卡從停滯狀態(tài)出來的唯一的方法是給其上電再放電。此外主機(jī)可明確地利用go_inactive_state命令把卡片處于停滯狀態(tài)。 卡采集和識(shí)別sd卡的總線是一單個(gè)主機(jī)(sd卡)和multi-slaves主機(jī)應(yīng)用程序(卡)總線。時(shí)鐘和電源線是常見的卡總線。在識(shí)別過程,主機(jī)通過自己的命令行訪問每一張卡片另行規(guī)定。sd卡的cid登記的二級(jí)管卡是用一種獨(dú)特的識(shí)別數(shù)字,它被用于在識(shí)別程序。此外,sd卡的主機(jī)可讀卡片的cid注冊(cè)使用read_cid sd卡的命令。cid登記是程序在制造平臺(tái)上對(duì)sd卡的測(cè)試和格式化程序。sd卡主機(jī)只能閱讀這個(gè)注冊(cè)并不能寫。一個(gè)內(nèi)部拉電阻器在dat3線可以用于檢測(cè)(插入/遷移卡)。本電阻器acmd42在數(shù)據(jù)傳輸(使用)時(shí)可以被斷開。額外的實(shí)用卡檢測(cè)方法中都能找到sd物理規(guī)格的應(yīng)用筆記所給出的現(xiàn)代化進(jìn)程。 卡狀態(tài)這張卡狀態(tài)分為以下兩大領(lǐng)域:卡狀態(tài)儲(chǔ)存在一個(gè)32位的狀態(tài)寄存器中，而這個(gè)寄存器是用來回應(yīng)主機(jī)命令的。狀態(tài)寄存器提供有關(guān)卡的現(xiàn)狀和完成編碼在過去的主機(jī)的命令。這張卡狀態(tài)可以通過send_status這個(gè)命令顯式地讀。被儲(chǔ)存在512位，回應(yīng)被請(qǐng)求的主機(jī)利用sd_status(acmd13)的命令命令。它作為一個(gè)單獨(dú)的數(shù)據(jù)塊。sd_status包括擴(kuò)展的狀態(tài)位，這些位關(guān)系到bus_width、安全相關(guān)位和未來中的具體應(yīng)用。 內(nèi)存陣列分區(qū)sd卡數(shù)據(jù)傳輸?shù)幕締挝皇且粋€(gè)字節(jié)。所有命令一個(gè)塊大小的的數(shù)據(jù)轉(zhuǎn)移操作需要總是定義塊長(zhǎng)度尺寸為字節(jié)的整數(shù)倍。一些特殊功能需要其他的分隔尺寸。圖1 - 2顯示內(nèi)存陣列分區(qū)。為初始?jí)K的指令, 使用了以下定義:塊-這個(gè)單位是涉及塊初始化讀和寫的命令。 它的規(guī)模是當(dāng)主機(jī)發(fā)送塊命令時(shí)所轉(zhuǎn)移的字節(jié)的數(shù)量。一個(gè)塊的大小是可編程的或是固定。在csd中存儲(chǔ)了關(guān)于塊得大小和可編程的信息?？刹脸龁卧拈g隔尺寸一般和初始化命令是不同的扇區(qū)-這個(gè)單位,是涉及擦除的命令。它的規(guī)模被擦除的部分的塊的大小。每臺(tái)設(shè)備扇區(qū)的大小是固定的。關(guān)于扇區(qū)大小的信息存儲(chǔ)在csd中。寫保護(hù)的設(shè)備, 使用了包括以下定義: wp組最小的單元可能被分成獨(dú)立的寫保護(hù)。它的規(guī)模是被一位寫保護(hù)的組的數(shù)量。對(duì)每個(gè)設(shè)備來說wp-組的大小是固定的。有關(guān)組信息被存儲(chǔ)在csd中。wp組一wp組二第二扇區(qū)第一扇區(qū)第三扇區(qū)第n扇區(qū)第一扇區(qū)第n扇區(qū)sd記憶卡塊n塊0保護(hù)區(qū)塊n塊0圖1-2內(nèi)存陣列分區(qū) sd卡的讀寫操作sd卡支持讀寫兩種模式，如圖所示多塊模式記憶扇區(qū)記憶扇區(qū)記憶扇區(qū) 記憶扇區(qū)記憶扇區(qū) 記憶扇區(qū)記憶扇區(qū)單模塊記憶扇區(qū)記憶扇區(qū)記憶扇區(qū) 記憶扇區(qū)記憶扇區(qū) 記憶扇區(qū)記憶扇區(qū) 圖1-3數(shù)據(jù)轉(zhuǎn)換格式單塊模式在這種模式下主機(jī)在一個(gè)預(yù)定義的長(zhǎng)度下讀或?qū)懸粋€(gè)數(shù)據(jù)塊。這些數(shù)據(jù)的塊傳輸是16位的crc被保護(hù)的，crc是在被接受單元發(fā)送和檢查時(shí)產(chǎn)生的。讀操作的塊長(zhǎng)度是由設(shè)備扇區(qū)的大小(512個(gè)字節(jié))所限制的能和單字節(jié)一樣大小。不允許錯(cuò)位的。每一個(gè)數(shù)據(jù)塊必須包含一個(gè)單獨(dú)的物理領(lǐng)域。塊長(zhǎng)度為寫操作必須相同的扇區(qū)的大小和啟動(dòng)地址排列成一個(gè)部門的界限。多個(gè)塊模式該機(jī)型是類似于單塊模式,但主機(jī)可讀/寫多個(gè)數(shù)據(jù)塊(都是相等的長(zhǎng)度),在連續(xù)內(nèi)存地址中會(huì)被儲(chǔ)存或檢索。操作終止以終止傳輸命令。錯(cuò)位與塊長(zhǎng)限制也適用于多塊和單塊一致數(shù)據(jù)傳輸速率sd卡的可操作使用的是一個(gè)單獨(dú)的數(shù)據(jù))或四線(dat0數(shù)據(jù)線(dat0-dat3)數(shù)據(jù)轉(zhuǎn)讓。最大的數(shù)據(jù)轉(zhuǎn)移率為一個(gè)單一的數(shù)據(jù)行, 第二是25-mb 100-mb每秒每(12 mb)使用4個(gè)數(shù)據(jù)傳輸線。 數(shù)據(jù)保護(hù)在卡片每個(gè)部門都是保護(hù)用誤差修正代碼(ecc)。人們對(duì)錯(cuò)誤校正碼的生成(在你的記憶卡)的時(shí)候這些扇區(qū)都被書面記錄并且驗(yàn)證了在數(shù)據(jù)被讀取。如果缺陷被發(fā)現(xiàn)后,數(shù)據(jù)被提前糾正送往主機(jī)。 擦除sd卡最小的可擦寫單元是一個(gè)扇區(qū)。為了加快擦除的速度，多個(gè)扇區(qū)可以同時(shí)被擦除。為了促進(jìn)選擇第一個(gè)開始的命令是被第二個(gè)命令和最后一個(gè)指令所允許的，所有范圍之內(nèi)的扇區(qū)將被選為擦除。0 寫保護(hù)兩個(gè)卡標(biāo)準(zhǔn)的寫保護(hù)可供選擇:臨時(shí)和永久性的。兩者皆可設(shè)置使用program_csd命令(見下文)。 永久寫保護(hù)點(diǎn),一旦被創(chuàng)立,就不能被清除。這一特點(diǎn)在sd卡實(shí)現(xiàn)控制器固件和不與物理編譯otp單元。注意:使用寫保護(hù)(工作)開關(guān)位于卡的邊上,以防止主機(jī)在卡上寫或者擦除數(shù)據(jù)。在csd中wp開關(guān)永遠(yuǎn)不會(huì)對(duì)臨時(shí)的或永久的wp位產(chǎn)生影響。 復(fù)制位在csd寄存器中sd卡的內(nèi)容可以作為原件或副本被使用。一旦被拷貝(標(biāo)記成一個(gè)副本),它不能被清除。復(fù)制位(sd卡是在測(cè)試過程中,編程格式化生產(chǎn)層)作為一個(gè)副本。sd卡可以購(gòu)買與復(fù)制或位元(復(fù)印件)清除,并說明卡是一個(gè)控制。此功能是實(shí)現(xiàn)控制器在sd卡固件而不能用一種物理編譯otp單元。2 csd寄存器d卡所有的配置信息儲(chǔ)存在csd寄存器中。寄存器的每個(gè)字節(jié)包含制造商數(shù)據(jù)和兩個(gè)最小有效字節(jié)包含主機(jī)控制數(shù)據(jù),卡復(fù)制、寫保護(hù)和用戶文件格式的想法。主機(jī)可以讀取csd注冊(cè)并改變主機(jī)使用send_csd控制和program_csd命令。1.5.10 sd card-spi模式該模式為sd卡的一個(gè)次要通訊協(xié)議。這種模式的一個(gè)子集的sd卡協(xié)議,一個(gè)spi設(shè)計(jì)與溝通渠道,普遍存在于摩托羅拉(和最近一些其他供應(yīng)商的)微控制器。 談判操作條件在操作條件談判的功能支持的sd卡總線的方法,在利用spi模式read_ocr(cmd58)命令。 主機(jī)應(yīng)工作在2.7 36伏特有效電壓范圍內(nèi)的卡片或者把卡在go_inactive停滯狀態(tài)通過發(fā)送命令給卡。 卡采集和識(shí)別主機(jī)必須通過總線知道當(dāng)前卡的鏈接數(shù)量。通過cs信號(hào)選擇是做具體卡(cd / dat3)。在內(nèi)部元器件庫(kù)中的上拉電阻cd / dat3線可以用于卡檢測(cè)(插入/遷移)。額外的實(shí)用卡檢測(cè)方法,可以在sd物理規(guī)格中發(fā)現(xiàn)。 卡狀態(tài)在spi模式,只有16位(包括錯(cuò)誤相關(guān)模式),可以去讀spi的32位的sd卡的狀態(tài)。使用acmd13可以讀的sd卡的狀態(tài),在sd總線模式下也一樣。 內(nèi)存陣列分區(qū)記憶在模式劃分,相當(dāng)于sd spi總線模式。所有讀和寫命令是在中給出的有限制的可尋址的位。 讀和寫操作支持在spi模式、單體及多塊數(shù)據(jù)傳輸模式。 數(shù)據(jù)傳輸速率在該模式,在每個(gè)方向只使用一根數(shù)據(jù)線。該模式的數(shù)據(jù)傳輸速率是相同的標(biāo)準(zhǔn)差主機(jī)模式的數(shù)據(jù)轉(zhuǎn)移率只使用一個(gè)數(shù)據(jù)行(每秒多達(dá)25 mbits)。 sd卡的數(shù)據(jù)保護(hù)同sd卡模式。 擦除同sd卡模式。 寫保護(hù)同sd卡模式。0 版權(quán)保護(hù)同sd卡模式. .附件2：外文原文（復(fù)印件）1. introduction to the sd card. introduction to the sdthe secure digital card is a flash-based memory card that is specifically designed to meet the security, capacity,performance and environmental requirements inherent in newly emerging audio and video consumer electronicdevices. the sd card includes a copyright protection mechanism that complies with the security of the sdmistandard, and is faster and capable of higher memory capacity. the sd card security system uses mutualauthentication and a “new cipher algorithm” to protect from illegal usage of the card content. a non-secured accessto the users own content is also available. the physical form factor, pin assignment and data transfer protocol areforward compatible with the sd card, with some additions.the sd card communication is based on an advanced nine-pin interface (clock, command, 4xdata and 3xpowerlines) designed to operate in a low voltage range. the communication protocol is defined as part of this specification. the sd card host interface supports regular multimediacard operation as well. in other words, multimediacard forward compatibility was kept. actually the main difference between sd card and multimediacard is the initialization process. the sd card specifications were originally defined by mei (matsushita electric company), toshiba corporation and sandisk corporation. currently, the specifications arecontrolled by the secure digital association (sda). the sandisk sd card was designed to be compatible with thesd card physical specification.the sd card interface allows for easy integration into any design, regardless of microprocessor used. for compatibility with existing controllers, the sandisk sd card offers, in addition to the sd card interface, an alternate communication protocol, which is based on the spi standard.the current sd card provides up to 1024 million bytes of memory using flash memory chips, which were designedespecially for use in mass storage applications. in addition to the mass storage specific flash memory chip, the sdcard includes an on-card intelligent controller which manages interface protocols,securityalgorithms for copyrightprotection, data storage and retrieval, as well as error correction code (ecc)algorithms, defect handling anddiagnostics, power management and clock control.figure 1-1. sd card block diagram1.1. scopethis document describes the key features and specifications of the sd card, as well as the information required tointerface this product to a host system.1.2. product modelsthe sd card is available in the capacities shown in table 1-1.1.3. system featuresthe sd card provides the following features: up to 2-gb of data storage. sd card protocol compatible. supports spi mode. targeted for portable and stationary applications for secured (copyrights protected) and non-secureddata storage. voltage range: basic communication (cmd0, cmd15, cmd55, acmd41): 2.0-3.6v. other commands and memory access: 2.7-3.6v. variable clock rate 0-25 mhz. up to 25 mb/sec data transfer rate (using 4 parallel data lines). maximum data rate with up to 10 cards. correction of memory field errors. copyrights protection mechanismcomplies with highest security of sdmi standard.introduction to the sd cardsandisk secure digital (sd) card product manual, rev. 2.2 2004 sandisk corporation 1-3 password protected of cards (not on all models). write protect feature using mechanical switch. built-in write protection features (permanent and temporary). card detection (insertion/removal). application-specific commands. comfortable erase mechanism.the performance of the communication channel is described in table 1-2.1.4. sd card standardsandisk sd cards are fully compatible with the following sd card physical layer specification standard:the sd card physical layer system specification, version 1.10this specification may be obtained from:sd card association53 muckelemi st.p.o. box 189san juan bautista, ca 95045-0189usaphone: 831-623-2107fax: 831-623-2248email: 1.5. functional descriptionsandisk sd cards contain a high level, intelligent subsystem as shown in figure 1-1. this intelligent (microprocessor) subsystem provides many capabilities not found in other types of memory cards. these capabilities include: host independence from details of erasing and programming flash memory. sophisticated system for managing defects (analogous to systems found in magnetic disk drives). sophisticated system for error recovery including a powerful error correction code (ecc). power management for low power operation.1.5.1. flash technology independencethe 512-byte sector size of the sd card is the same as that in an ide magnetic disk drive. to write or read a sector(or multiple sectors), the host computer software simply issues a read or write command to the sd card. thiscommand contains the address. the host software then waits for the command to complete. the host software does not get involved in the details of how the flash memory is erased, programmed or read. this is extremely importantas flash devices are expected to get more and more complex in the future. because the sd card uses an intelligent on-board controller, the host system software will not require changing as new flash memory evolves. in other words, systems that support the sd card today will be able to access future sandisk sd cards built with new flash technology without having to update or change host software.1.5.2. defect and error managementsd cards contain a sophisticated defect and error management system. this system is analogous to the systems found in magnetic disk drives and in many cases offers enhancements. for instance, disk drives do not typically perform a read after write to confirm the data is written correctly because of the performance penalty that would be incurred. sd cards do a read after write under margin conditions to verify that the data is written correctly. in the rare case that a bit is found to be defective, sd cards replace this bad bit with a spare bit within the sector header. if necessary, sd cards will even replace the entire sector with a spare sector. this is completely transparent to the host and does not consume any user data space.the sd cards soft error rate specification is much better than the magnetic disk drive specification. in the extremely rare case a read error does occur, sd cards have innovative algorithms to recover the data. this is similar to using retries on a disk drive but is much more sophisticated. the last line of defense is to employ a powerful ecc to correct the data. if ecc is used to recover data, defective bits are replaced with spare bits to ensure they do not cause any future problems. these defect and error management systems coupled with the solid-state construction give sd cards unparalleled reliability.1.5.3. copyright protectiona detailed description of the copyright protection mechanism and related security sd card commands can be found in the sd card security specification document from the sd card association. all sd card security related commands operate in the data transfer mode.as defined in the sdmi specification, the data content that is saved in the card is saved already encrypted and it passes transparently to and from the card. no operation is done on the data and there is no restriction to read the data at any time. associated with every data packet (song, for example) that is saved in the unprotected memory there is a special data that is saved in a protected memory area. for any access (any read, write or erase command) from/to the data in the protected area. for an authentication procedure is done between the card and the connected device, either the lcm (pc for example) or the pd (portable device, such as sd player). after the authentication process passes, the card is ready to accept or give data from/to the connected device. while the card is in the secured mode of operation (after the authentication succeeded) the argument and the associated data that is sent to the card or read from the card are encrypted. at the end of the read, write or erase operation, the card gets out automatically of its secured mode. 1.5.4. endurancesandisk sd cards have an endurance specification for each sector of 100,000 writes typical (reading a logical sector is unlimited). this far exceeds what is typically required in nearly all applications of sd cards. for example, even very heavy use of the sd card in digital still cameras, cellular phones, personal communicators, pagers and voice recorders will use only a fraction of the total endurance over the typical devices lifetime. for instance, it would take over 10 years to wear out an area on the sd card on which a file of any size (from 512 bytes to maximum capacity) was rewritten 3 times per hour, 8 hours a day, 365 days per year. with typical applications, the endurance limit is not of any practical concern to the vast majority of users.1.5.5. wear levelingwear-leveling is an intrinsic part of the erase pooling functionality of sd using nand memory. the sd cardswear level command is supported as a nop operation to maintain backward compatibility with existing softwareutilities.1.5.6. using the erase commandthe erase (sector or group) command provides the capability to substantially increase the write performance of the sd card. once a sector has been erased using the erase command, a write to that sector will be much faster. this is because a normal write operation includes a separate sector erase prior to write.1.5.7. automatic sleep modea unique feature of the sandisk sd card (and other sandisk products) is automatic entrance and exit from sleepmode. upon completion of an operation, the sd card will enter the sleep mode to conserve power if no further commands are received within 5msec. the host does not have to take any action for this to occur. in most systems, the sd card is in sleep mode except when the host is accessing it, thus conserving power.when the host is ready to access the sd card and it is in sleep mode, any command issued to the sd card willcause it to exit sleep and respond.1.5.8. hot insertionsupport for hot insertion will be required on the host but will be supported through the connector. connectormanufacturers will provide connectors that have power pins long enough to be powered before contact is made with the other pins. please see connector data sheets for more details. this approach is similar to that used in pcmcia and mmca devices to allow for hot insertion.1.5.9. sd cardsd