數(shù)據(jù)采集與傳輸系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)

畢業(yè)設(shè)計(jì)（論文）題目數(shù)據(jù)采集與傳輸系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)院（系）信息科學(xué)與工程學(xué)院電子系專業(yè)電子信息工程屆別學(xué)號(hào)姓名指導(dǎo)老師#路（ASIC）,加固工藝的器件需要確定如何驗(yàn)證設(shè)計(jì)程序庫(kù)而不是設(shè)備硬度。也就是說(shuō)，有了測(cè)試芯片，我們是不是就可以在未來(lái)器件上使用相同的程序庫(kù)了？試想，如果賣主A的設(shè)計(jì)的新的固化工藝程序庫(kù)可移植性可比賣主B和C的都好，那么A設(shè)計(jì)，測(cè)試的測(cè)試芯片就是可接受的了。9個(gè)月后，美國(guó)航天局飛行項(xiàng)目就會(huì)使用賣主A的程序庫(kù)設(shè)計(jì)了新器件進(jìn)行組合了。這是否需要完成輻射條件測(cè)試？回答這個(gè)問(wèn)題之前，先看一下其他的問(wèn)題。如何完整地測(cè)試芯片？所有程序庫(kù)元素來(lái)驗(yàn)證每個(gè)單元是否有足夠的統(tǒng)計(jì)覆蓋？如果美國(guó)航天局新的設(shè)計(jì)部分使用了設(shè)計(jì)程序庫(kù)或使用了沒(méi)有充分描述的部分，可能就需要全部測(cè)試了。當(dāng)然，如果固化的部分工藝依靠一個(gè)進(jìn)程的固有抗輻射硬度，也可以放棄一些測(cè)試（如SEL早先的樣本）。另外，其他考慮因素還包括運(yùn)作速度和工作電壓。例如，如果在電源電壓3.3V的條件下，用測(cè)試芯片靜態(tài)地測(cè)試單粒子效應(yīng)，所測(cè)得的數(shù)據(jù)在電源電壓2.5V操作頻率100MHz的條件下是否適用？動(dòng)態(tài)因素（即非靜態(tài)操作）包括單粒子瞬變（SETs）的普及效果。更高的頻率可能更關(guān)注這些。需要考慮的因素是，設(shè)計(jì)程序庫(kù)，測(cè)試范圍，鑄造特點(diǎn)必須是已知的，并且深刻理解測(cè)試用途。如果所有這些因素都已經(jīng)具備或測(cè)試芯片已被驗(yàn)證，那么測(cè)試就沒(méi)有必要了。美國(guó)航天局的電子零件封裝（NEPP）計(jì)劃是為了探討這些因素的類型。用8051單片機(jī)評(píng)估加固工藝由于性能的不斷提高和功耗的不斷降低，微控制器在美國(guó)航天局和國(guó)防部的系統(tǒng)設(shè)計(jì)上的應(yīng)用正越來(lái)越多。現(xiàn)在，美國(guó)航天局和國(guó)防部計(jì)劃正在不斷地改進(jìn)固化工藝。微控制器是一個(gè)這樣的工具，正在深入量化抗輻射固化的改進(jìn)。這些計(jì)劃的實(shí)例是Mission研究公司（MRC）與高級(jí)微電子研究所（這項(xiàng)研究的重點(diǎn)）所研制的8051微控制器。在自然空間輻射環(huán)境中，由于這些固化工藝的使用，美國(guó)宇航局在航天飛行中系統(tǒng)中使用驗(yàn)證技術(shù)成為必要。8051單片機(jī)是一個(gè)行業(yè)標(biāo)準(zhǔn)架構(gòu)，被廣泛接受和應(yīng)用，并作為一種開(kāi)發(fā)工具。有許多工業(yè)供應(yīng)商，他們供應(yīng)這種控制器或把這種控制器集成到某種類型的系統(tǒng)芯片的結(jié)構(gòu)。醫(yī)學(xué)研究理事會(huì)和高級(jí)微電子研究所都選擇這個(gè)設(shè)備，但他們論證的是兩種截然不同固化工藝。醫(yī)學(xué)研究理事會(huì)的實(shí)例是使用時(shí)間鎖存，需要具體時(shí)間以確保單粒子效應(yīng)減少到最低限度。高級(jí)微電子研究所采用超低功耗，以及布局和建筑固化工藝的設(shè)計(jì)原則來(lái)實(shí)現(xiàn)其結(jié)果。這些是與Aeroflex聯(lián)合技術(shù)微電子中心（UTMC）完全不同的方法，抗輻射固化的8051的工業(yè)供應(yīng)商，利用抗輻射固化進(jìn)程研制自己的8051單片機(jī)。一臺(tái)設(shè)備廣泛涉及的技術(shù)使得8051成為技術(shù)評(píng)價(jià)的理想載體這項(xiàng)工作的目標(biāo)是從高級(jí)微電子研究所得到CMOS超低功耗輻射容錯(cuò)進(jìn)程的技術(shù)評(píng)價(jià)[3]。其他兩個(gè)過(guò)程--英特爾的8051商業(yè)設(shè)備標(biāo)準(zhǔn)和采用國(guó)家最先進(jìn)的加工從達(dá)拉斯半導(dǎo)體版本—是這個(gè)進(jìn)程的基礎(chǔ)，。商業(yè)研究一一比較了他們的成本效益，性能和可靠性。技術(shù)性能的評(píng)價(jià)是為測(cè)試微控制器開(kāi)發(fā)硬件和軟件。完備進(jìn)程中目的是優(yōu)化測(cè)試過(guò)程以盡可能獲得完整的評(píng)價(jià)。這包括利用現(xiàn)有的硬件和在微控制器上運(yùn)行的軟件對(duì)所有子處理器進(jìn)行評(píng)價(jià)。這個(gè)進(jìn)程還會(huì)使我們較完整地理解如何測(cè)試復(fù)雜的結(jié)構(gòu)，如微控制器，以及將來(lái)如何更有效地測(cè)試這些結(jié)構(gòu)。測(cè)試裝置這一試驗(yàn)的評(píng)價(jià)使用了三款器件。首先是美國(guó)航天局的設(shè)備，這是進(jìn)行評(píng)估主要設(shè)備。其他兩個(gè)設(shè)備是兩種版本的商業(yè)8051，分別由英特爾公司和美國(guó)達(dá)拉斯半導(dǎo)體制造。英特爾的設(shè)備是無(wú)存儲(chǔ)器型，這是經(jīng)典的8052MCS-51單片機(jī)電路版。他們工作環(huán)境是額定電壓+5伏，溫度范圍在0至70°C,時(shí)鐘頻率為3.5兆赫至24兆赫。他們由英特爾P629.0CHMOSIII-E進(jìn)程制造的。達(dá)拉斯半導(dǎo)體器件都很相似因?yàn)樗麄兌际荝OMless8052單片機(jī)，但他們加強(qiáng)方式不同。他們的額定電壓從4.25至5.5,溫度在0到70°C,時(shí)鐘頻率高達(dá)25兆赫。第二次全內(nèi)置串口，增設(shè)七個(gè)中斷，一個(gè)看門狗定時(shí)器，一個(gè)掉電復(fù)位，雙數(shù)據(jù)指針和變速外設(shè)訪問(wèn)。此外，重新設(shè)計(jì)技術(shù)核心，最終使該機(jī)器周期縮短，從而得到有效的處理能力，這大約是2.5倍（快）比標(biāo)準(zhǔn)的8052器件。不同于器件工作所固有的功能，這些功能沒(méi)有被利用是為了達(dá)拉斯和英特爾的測(cè)試代碼最大限度地相似。CMOS設(shè)備是MSC-51系列的一個(gè)版本，與超低功耗（ULP）進(jìn)程代工許可的C8051HDL核心兼容。C8051設(shè)備在電源電壓為500毫伏運(yùn)行，高壓部分包括一個(gè)片上輸入/輸出信號(hào)電平轉(zhuǎn)換接口。超低功耗輻射容錯(cuò)技術(shù)C8051設(shè)備需要兩個(gè)單獨(dú)的電源電壓；500毫伏和理想的接口電壓。C8051是ROMless與MSC-51系列指令系統(tǒng)兼容的。五，測(cè)試硬件8051被測(cè)設(shè)備（DUT）作為實(shí)用電腦組成部分進(jìn)行了測(cè)試。除了被測(cè)設(shè)備本身，在被測(cè)設(shè)備計(jì)算機(jī)其他組成部分從立即地區(qū)輻射光束被刪除。一個(gè)獨(dú)特的硬連線標(biāo)識(shí)符字節(jié)所帶有的小卡（每種被測(cè)設(shè)備封裝類型有一個(gè)）控制被測(cè)設(shè)備，晶體，并旁路電容器（和電壓電平轉(zhuǎn)換為被測(cè)設(shè)備）。這種“被測(cè)設(shè)備板”是由短60導(dǎo)體帶狀電纜連接到“主板”。各主板的所有其他組件需要被測(cè)設(shè)備計(jì)算機(jī)完成，包括在一些設(shè)計(jì)名義上是沒(méi)有必要的組件（如外部?jī)?nèi)存，外部ROM和地址鎖存器）。被測(cè)設(shè)備計(jì)算機(jī)和測(cè)試控制計(jì)算機(jī)是由串行電纜連接，而兩者之間的通信由控制器（即運(yùn)行定制的串行接口軟件）建立。這個(gè)控制器軟件涉及被測(cè)設(shè)備的命令，被測(cè)設(shè)備碼的下載，和被測(cè)設(shè)備輻射前后搜集來(lái)的實(shí)時(shí)錯(cuò)誤。1赫茲信號(hào)源為被測(cè)設(shè)備提供了一個(gè)外部看門狗定時(shí)信號(hào)，其看門狗輸出是通過(guò)一個(gè)示波器監(jiān)測(cè)。監(jiān)測(cè)電源供應(yīng)來(lái)得到閉鎖指示。六測(cè)試軟件8051測(cè)試軟件的概念很簡(jiǎn)單。它的目的是要作為一個(gè)模塊化設(shè)計(jì)，為被測(cè)設(shè)備的每一個(gè)具體部分的設(shè)計(jì)一系列小型試驗(yàn)程序。因?yàn)槊總€(gè)試驗(yàn)是獨(dú)立的，他們是獨(dú)立加載的，在被測(cè)設(shè)備也是相互獨(dú)立執(zhí)行的。這將確保在測(cè)試時(shí)只有8051被測(cè)設(shè)備所需的部分在運(yùn)行，并有助于測(cè)試時(shí)發(fā)生錯(cuò)誤的精確定位。全部測(cè)試程序先駐存在控制器電腦中，然后通過(guò)串行接口加載到被測(cè)設(shè)備計(jì)算機(jī)。這樣，個(gè)別試驗(yàn)可以在任何時(shí)間被修改。還可以制定和補(bǔ)充額外的測(cè)試，而不會(huì)影響整體測(cè)試設(shè)計(jì)。只有駐存在被測(cè)設(shè)備永久編碼，是啟動(dòng)代碼和在控制器PC與被測(cè)設(shè)備建立之間的通信的串行代碼裝入例行程序。所有執(zhí)行的測(cè)試程序：?外部通用異步接收和發(fā)送裝置（UART接口），用來(lái)傳送錯(cuò)誤信息和控制器計(jì)算機(jī)之間的通信。?外部實(shí)時(shí)時(shí)鐘，作為數(shù)據(jù)錯(cuò)誤標(biāo)記。?看門狗，必要時(shí)為8051正常運(yùn)行和重新啟動(dòng)的可視化確認(rèn)提供測(cè)試代碼。?“混亂”的例行程序，如果它偏離代碼空間就會(huì)重置程序計(jì)數(shù)器。?外部遙測(cè)數(shù)據(jù)存儲(chǔ)器，數(shù)據(jù)傳輸發(fā)生中斷時(shí)提供的數(shù)據(jù)備份。應(yīng)當(dāng)指出的是，考慮到所有接收數(shù)據(jù)最高的可靠性，每個(gè)試驗(yàn)中，返回遙測(cè)（包括時(shí)間標(biāo)記）被同時(shí)送往測(cè)試控制器和遙測(cè)內(nèi)存。每一個(gè)軟件測(cè)試使用簡(jiǎn)要介紹如下：中斷這項(xiàng)測(cè)試用到6個(gè)可用中斷矢量圖中的4個(gè)來(lái)觸發(fā)例程（串行，外部，定時(shí)器0溢出，以及定時(shí)器1溢出），累加器定期地與一個(gè)已知值比較，然后啟動(dòng)例行程序順序地修改累加器的值。意外值傳與寄存器信息一起傳送。邏輯這個(gè)測(cè)試進(jìn)行了一系列的邏輯和數(shù)學(xué)計(jì)算，并提供三種類型的錯(cuò)誤鑒定：1）加法/減法，2）邏輯運(yùn)算，3）乘法/除法。計(jì)算和期望值的所有不匹配與其他有關(guān)寄存器信息一起傳送。存儲(chǔ)器這項(xiàng)測(cè)試間接地用0x55模式裝在內(nèi)部數(shù)據(jù)存儲(chǔ)器的地址D：0x20到D：0xff（或D：0x20到D：0x080為CMOS超低功耗輻射容錯(cuò)被測(cè)設(shè)備）。當(dāng)出錯(cuò)信息和寄存器值被傳送，不斷進(jìn)行比較，糾正。程序計(jì)數(shù)器取不同的偏移地址時(shí)，該程序計(jì)數(shù)器是用來(lái)取常數(shù)的。常數(shù)與已知值進(jìn)行比較，不匹配結(jié)果與有關(guān)寄存器信息一起傳送。寄存器這項(xiàng)測(cè)試程序裝在中的四（0,1,2,3）段的通用寄存器或者0xAA（段0和2）或0x55（段1和3）。模式交替為了測(cè)試狀態(tài)字（PSW）特殊功能寄存器，其中控制通用寄存器段的選擇。然后通用寄存器段，比較他們的預(yù)期值。所有不匹配被更正，錯(cuò)誤信息傳送。特殊功能寄存器（SFR）這項(xiàng)測(cè)試使用可特殊功能寄存器21位中的12位的已知靜態(tài)值，然后不斷地比較已知值與當(dāng)前值。不匹配與已知值和錯(cuò)誤信息被重新裝入。棧這項(xiàng)測(cè)試通過(guò)把操作數(shù)壓入和彈出堆棧進(jìn)行運(yùn)算。意外值由于堆棧的錯(cuò)誤或堆棧指針本身和有關(guān)的寄存器信息被傳送。七測(cè)試方法通過(guò)執(zhí)行位于地址0x0000指令代碼來(lái)啟動(dòng)被測(cè)設(shè)備計(jì)算機(jī)。起初，這個(gè)地址的設(shè)備是一個(gè)以前載有“開(kāi)機(jī)/串行裝載機(jī)”代碼的可擦寫可編程只讀存儲(chǔ)器。此代碼初始化被測(cè)設(shè)備計(jì)算機(jī)及接口通過(guò)串行連接的計(jì)算機(jī)的控制，“測(cè)試控制器”。被測(cè)設(shè)備計(jì)算機(jī)下載測(cè)試代碼并把它放入程序代碼存儲(chǔ)器（位于被測(cè)設(shè)備計(jì)算機(jī)主板）。然后啟動(dòng)電路，同時(shí)進(jìn)行兩個(gè)功能：被測(cè)設(shè)備的復(fù)位線保持有效一段時(shí)間（大約10毫秒）；并且，駐存在程序碼RAM的測(cè)試代碼映射到地址0x0000（在被測(cè)設(shè)備計(jì)算機(jī)內(nèi)存空間該可擦寫可編程只讀存儲(chǔ)器將不再被訪問(wèn)）。蘇醒后，從重置，通過(guò)執(zhí)行地址0x0000指令代碼再次啟動(dòng)被測(cè)設(shè)備電腦，但這個(gè)時(shí)候，代碼不是啟動(dòng)/串行裝入程序代碼，而是測(cè)試代碼。不論在被測(cè)設(shè)備計(jì)算機(jī)的功能性如何，測(cè)試控制計(jì)算機(jī)始終保留了強(qiáng)制重置/映射功能。因此，如果測(cè)試運(yùn)行沒(méi)有一個(gè)單一事件功能中斷（SEFI）無(wú)論是被測(cè)設(shè)備計(jì)算機(jī)本身或測(cè)試控制器可以終止了測(cè)試，并允許執(zhí)行后測(cè)試功能。如果SEFI發(fā)生，測(cè)試控制器強(qiáng)制重新啟動(dòng)到開(kāi)機(jī)/串行裝入程序代碼然后執(zhí)行后的測(cè)試功能。在被測(cè)設(shè)備的任何測(cè)試，被測(cè)設(shè)備行使的部分功能（例如，寄存器操作或內(nèi)部RAM的檢查，或定時(shí)器操作）在最高利用可能，同時(shí)使最小定期報(bào)告的測(cè)試控制計(jì)算機(jī)轉(zhuǎn)達(dá)的被測(cè)設(shè)備計(jì)算機(jī)仍然起作用。如果此報(bào)告停止，測(cè)試控制器知道了，一個(gè)SEFI發(fā)生。這種定期的數(shù)據(jù)被稱為“遙測(cè)”。如果被測(cè)設(shè)備遇到了一個(gè)錯(cuò)誤，不能中斷功能（例如，數(shù)據(jù)寄存器不匹配）通過(guò)描述的錯(cuò)誤串口有發(fā)出一個(gè)更多的長(zhǎng)篇報(bào)告，并繼續(xù)進(jìn)行測(cè)試。ValidationandTestingofDesignHardeningforSingle

EventEffectsUsingthe8051MicrocontrollerAbstractWiththedearthofdedicatedradiationhardenedfoundries,newandnoveltechniquesarebeingdevelopedforhardeningdesignsusingnon-dedicatedfoundryservices.Inthispaper,wewilldiscusstheimplicationsofvalidatingthesemethodsforthesingleeventeffects(SEE)inthespaceenvironment.Topicsincludethetypesofteststhatarerequiredandthedesigncoverage(i.e.,designlibraries:dotheyneedvalidatingforeachapplication?).Finally,an8051microcontrollercorefromNASAInstituteofAdvancedMicroelectronics(IApE)CMOSUltraLowPowerRadiationTolerant(CULPRiT)designisevaluatedforSEEmitigativetechniquesagainsttwocommercial8051devices.IndexTermsSingleEventEffects,Hardened-By-Design,microcontroller,radiationeffects.I.INTRODUCTIONNASAconstantlystrivestoprovidethebestcaptureofsciencewhileoperatinginaspaceradiationenvironmentusingaminimumofresources[1,2].Witharelativelylimitedselectionofradiation-hardenedmicroelectronicdevicesthatareoftentwoormoregenerationsofperformancebehindcommercialstate-ofthe-arttechnologies,NASA'sperformanceofthistaskisquitechallenging.Onemethodofalleviatingthisisbytheuseofcommercialfoundryalternativeswithnoorminimallyinvasivedesigntechniquesforhardening.Thisisoftencalledhardened-by-design(HBD).Buildingcustom-typeHBDdevicesusingdesignlibrariesandautomateddesigntoolsmayprovideNASAthesolutionitneedstomeetstringentscienceperformancespecificationsinatimely,cost-effective,andreliablemanner.However,onequestionstillexists:traditionalradiation-hardeneddeviceshavelotand/orwaferradiationqualificationtestsperformed;whattypesoftestsarerequiredforHBDvalidation?TESTINGHBDDEVICESCONSIDERATIONSTestmethodologiesintheUnitedStatesexisttoqualifyindividualdevicesthroughstandardsandorganizationssuchasASTM,JEDEC,andMIL-STD-883.Typically,TID(Co-60)andSEE(heavyionand/orproton)arerequiredfordevicevalidation.SowhatisuniquetoHBDdevices?Asopposedtoa“regular”commercial-off-the-shelf(COTS)deviceorapplicationspecificintegratedcircuit(ASIC)wherenohardeninghasbeenperformed,oneneedstodeterminehowvalidatedisthedesignlibraryasopposedtodeterminingthedevicehardness.Thatis,byusingtestchips,canwe“qualify”afuturedeviceusingthesamelibrary?ConsiderifVendorAhasdesignedanewHBDlibraryportabletofoundriesBandC.Atestchipisdesigned,tested,anddeemedacceptable.NinemonthslateraNASAflightprojectentersthemixbydesigninganewdeviceusingVendorA'slibrary.Doesthisdevicerequirecompleteradiationqualificationtesting?Toanswerthis,otherquestionsmustbeasked.Howcompletewasthetestchip?Wastheresufficientstatisticalcoverageofalllibraryelementstovalidateeachcell?IfthenewNASAdesignusesapartiallyorinsufficientlycharacterizedportionofthedesignlibrary,fulltestingmightberequired.Ofcourse,ifpartoftheHBDwasrelyingoninherentradiationhardnessofaprocess,someofthetests(likeSELintheearlierexample)maybewaived.Otherconsiderationsincludespeedofoperationandoperatingvoltage.Forexample,ifthetestchipwastestedstaticallyforSEEatapowersupplyvoltageof3.3V,isthedataapplicabletoa100MHzoperatingfrequencyat2.5V?Dynamicconsiderations(i.e.,nonstaticoperation)includethepropagatedeffectsofSingleEventTransients(SETs).Thesecanbeagreaterconcernathigherfrequencies.Thepointoftheconsiderationsisthatthedesignlibrarymustbeknown,thecoverageusedduringtestingisknown,thetestapplicationmustbethoroughlyunderstoodandthecharacteristicsofthefoundrymustbeknown.Ifalltheseareapplicableorhavebeenvalidatedbythetestchip,thennotestingmaybenecessary.AtaskwithinNASA'sElectronicPartsandPackaging(NEPP)Programwasperformedtoexplorethesetypesofconsiderations.HBDTECHNOLOGYEVALUATIONUSINGTHE8051MICROCONTROLLERWiththeirincreasingcapabilitiesandlowerpowerconsumption,microcontrollersareincreasinglybeingusedinNASAandDODsystemdesigns.ThereareexistingNASAandDoDprogramsthataredoingtechnologydevelopmenttoprovideHBD.Microcontrollersareonesuchvehiclethatisbeinginvestigatedtoquantifytheradiationhardnessimprovement.Examplesoftheseprogramsarethe8051microcontrollerbeingdevelopedbyMissionResearchCorporation(MRC)andtheIApE(thefocusofthisstudy).AstheseHBDtechnologiesbecomeavailable,validationofthetechnology,inthenaturalspaceradiationenvironment,forNASA'suseinspaceflightsystemsisrequired.The8051microcontrollerisanindustrystandardarchitecturethathasbroadacceptance,wide-rangingapplicationsanddevelopmenttoolsavailable.Therearenumerouscommercialvendorsthatsupplythiscontrollerorhaveitintegratedintosometypeofsystem-on-a-chipstructure.BothMRCandIApEchosethisdevicetodemonstratetwodistinctlydifferenttechnologiesforhardening.TheMRCexampleofthisistousetemporallatchesthatrequirespecifictimingtoensurethatsingleeventeffectsareminimized.TheIApEtechnologyusesultralowpower,andlayoutandarchitectureHBDdesignrulestoachievetheirresults.ThesearefundamentallydifferentthantheapproachbyAeroflex-UnitedTechnologiesMicroelectronicsCenter(UTMC),thecommercialvendorofaradiation—hardened8051,thatbuilttheir8051microcontrollerusingradiationhardenedprocesses.Thisbroadrangeoftechnologywithinonedevicestructuremakesthe8051anidealvehicleforperformingthistechnologyevaluation.TheobjectiveofthisworkisthetechnologyevaluationoftheCULPRiTprocess[3]fromIApE.Theprocesshasbeenbaselinedagainsttwootherprocesses,thestandard8051commercialdevicefromIntelandaversionusingstate-of-the-artprocessingfromDallasSemiconductor.Byperformingthisside-by-sidecomparison,thecostbenefit,performance,andreliabilitytradestudycanbedone.Intheperformanceofthetechnologyevaluation,thistaskdevelopedhardwareandsoftwarefortestingmicrocontrollers.Athoroughprocesswasdonetooptimizethetestprocesstoobtainascompleteanevaluationaspossible.Thisincludedtakingadvantageoftheavailablehardwareandwritingsoftwarethatexercisedthemicrocontrollersuchthatallsubstructuresoftheprocessorwereevaluated.Thisprocessisalsoleadingtoamorecompleteunderstandingofhowtotestcomplexstructures,suchasmicrocontrollers,andhowtomoreefficientlytestthesestructuresinthefuture.TESTDEVICESThreedeviceswereusedinthistestevaluation.ThefirstistheNASACULPRiTdevice,whichistheprimarydevicetobeevaluated.Theothertwodevicesaretwoversionsofacommercial8051,manufacturedbyIntelandDallasSemiconductor,respectively.TheInteldevicesaretheROMless,CMOSversionoftheclassic8052MCS-51microcontroller.Theyareratedforoperationat+5V,overatemperaturerangeof0to70°Candataclockspeedsof3.5MHzto24MHz.TheyaremanufacturedinIntel'sP629.0CHMOSIII-Eprocess.TheDallasSemiconductordevicesaresimilarinthattheyareROMless8052microcontrollers,buttheyareenhancedinvariousways.Theyareratedforoperationfrom4.25to5.5Voltsover0to70°Catclockspeedsupto25MHz.Theyhaveasecondfullserialportbuiltin,sevenadditionalinterrupts,awatchdogtimer,apowerfailreset,dualdatapointersandvariablespeedperipheralaccess.Inaddition,thecoreisredesignedsothatthemachinecycleisshortenedformostinstructions,resultinginaneffectiveprocessingabilitythatisroughly2.5timesgreater(faster)thanthestandard8052device.Noneofthesefeatures,otherthanthoseinherentinthedeviceoperation,wereutilizedinordertomaximizethesimilaritybetweentheDallasandInteltestcodes.TheCULPRiTtechnologydeviceisaversionoftheMSC-51familycompatibleC8051HDLcorelicensedfromtheUltraLowPower(ULP)processfoundry.TheCULPRiTtechnologyC8051deviceisdesignedtooperateatasupplyvoltageof500mVandincludesanon-chipinput/outputsignallevel-shiftinginterfacewithconventionalhighervoltageparts.TheCULPRiTC8051devicerequirestwoseparatesupplyvoltages;the500mVandthedesiredinterfacevoltage.TheCULPRiTC8051isROMlessandisintendedtobeinstructionsetcompatiblewiththeMSC-51family.TESTHARDWAREThe8051DeviceUnderTest(DUT)wastestedasacomponentofafunctionalcomputer.AsidefromDUTitself,theothercomponentsoftheDUTcomputerwereremovedfromtheimmediateareaoftheirradiationbeam.Asmallcard(oneperDUTpackagetype)withauniquehard-wiredidentifierbytecontainedtheDUT,itscrystal,andbypasscapacitors(andvoltagelevelshiftersfortheCULPRiTDUTs).This"DUTBoard"wasconnectedtothe"MainBoard"byashort60-conductorribboncable.TheMainBoardhadallothercomponentsrequiredtocompletetheDUTComputer,includingsomewhichnominallyarenotnecessaryinsomedesigns(suchasexternalRAM,externalROMandaddresslatch).TheDUTComputerandtheTestControlComputerwereconnectedviaaserialcableandcommunicationswereestablishedbetweenthetwobytheController(thatrunscustomdesignedserialinterfacesoftware).ThisControllersoftwareallowedforcommandingoftheDUT,downloadingDUTCodetotheDUT,andreal-timeerrorcollectionfromtheDUTduringandpostirradiation.A1HzsignalsourceprovidedanexternalwatchdogtimingsignaltotheDUT,whosewatchdogoutputwasmonitoredviaanoscilloscope.Thepowersupplywasmonitoredtoprovideindicationoflatchup.TESTSOFTWAREThe8051testsoftwareconceptisstraightforward.ItwasdesignedtobeamodularseriesofsmalltestprogramseachexercisingaspecificpartoftheDUT.Sinceeachtestwasstandalone,theywereloadedindependentlyofeachotherforexecutionontheDUT.Thisensuredthatonlythedesiredportionofthe8051DUTwasexercisedduringthetestandhelpedpinpointlocationoferrorsthatoccurduringtesting.AlltestprogramsresidedonthecontrollerPCuntilloadedviatheserialinterfacetotheDUTcomputer.Inthisway,individualtestscouldhavebeenmodifiedatanytimewithoutthenecessityofburningPROMs.Additionaltestscouldhavealsobeendevelopedandaddedwithoutimpactingtheoveralltestdesign.Theonlypermanentcode,whichwasresidentontheDUT,wasthebootcodeandserialcodeloaderroutinesthatestablishedcommunicationsbetweenthecontrollerPCandtheDUT.Alltestprogramsimplemented:?AnexternalUniversalAsynchronousReceiveandTransmitdevice(UART)fortransmissionoferrorinformationandcommunicationtocontrollercomputer.?Anexternalreal-timeclockfordataerrortag.?Awatchdogroutinedesignedtoprovidevisualverificationof8051healthandrestarttestcodeifnecessary.?A"foul-up"routinetoresetprogramcounterifitwandersoutofcodespace.?Anexternaltelemetrydatastoragememorytoprovidebackupofdataintheeventofaninterruptionindatatransmission.Thebriefdescriptionofeachofthesoftwaretestsusedisgivenbelow.Itshouldbenotedthatforeachtest,thereturnedtelemetry(includingtimetag)wassenttoboththetestcontrollerandthetelemetrymemory,givingthehighestreliabilitythatalldataiscaptured.Interrupt—Thistestused4of6availableinterruptvectors(Serial,External,TimerOOverflow,andTimer1Overflow)totriggerroutinesthatsequentiallymodifiedavalueintheaccumulatorwhichwasperiodicallycomparedtoaknownvalue.Unexpectedvaluesweretransmittedwithregisterinformation.Logic—Thistestperformedaseriesoflogicandmathcomputationsandprovidedthreetypesoferroridentifications:1)addition/subtraction,2)logicand3)multiplication/division.Allmiscomparesofcomputationsandexpectedresultsweretransmittedwithotherrelevantregisterinformation.Memory—ThistestloadedinternaldatamemoryatlocationsD:0x20throughD:Oxff(orD:Ox2OthroughD:OxO8OfortheCULPRiTDUT),indirectly,withanOx55pattern.Compareswereperformedcontinuouslyandmiscompareswerecorrectedwhileerrorinformationandregistervaluesweretransmitted.ProgramCounter-Theprogramcounterwasusedtocontinuouslyfetchconstantsatvariousoffsetsinthecode.Constantswerecomparedwithknownvaluesandmiscomparesweretransmittedalongwithrelevantregisterinformation.Registers—Thistestloadedeachoffour(0,1,2,3)banksofgeneral-purposeregisterswitheitherOxAA(forbanksOand2)orOx55(forbanks1and3).ThepatternwasalternatedinordertotesttheProgramStatusWord(PSW)specialfunctionregister,whichcontrolsgeneral-purposeregisterbankselection.General-purposeregisterbankswerethencomparedwiththeirexpectedvalues.Allmiscompareswerecorrectedanderrorinformationwastransmitted.SpecialFunctionRegisters(SFR)—Thistestusedlearnedstaticvaluesof12out21availableSFRsandthenconstantlycomparedthelearnedvaluewiththecurrentone.Miscompareswerereloadedwithlearnedvalueanderrorinformationwastransmitted.Stack—Thistestperformedarithmeticbypushingandpoppingoperandsonthestack.Unexpectedresultswereattributedtoerrorsonthestackortothestackpointeritselfandweretransmittedwithreleva