Iinkqubo zokugcina izinto zanamhlanje azikhuli nje kuphela kwii-terabits kwaye zinezinga eliphezulu lokudluliselwa kwedatha, kodwa zikwafuna amandla amancinci kwaye zihlala kwindawo encinci. Ezi nkqubo zikwafuna uqhagamshelo olungcono ukuze zibonelele ngokuguquguquka okungakumbi. Abayili bafuna uqhagamshelo oluncinci ukuze banike amazinga edatha afunekayo namhlanje okanye kwixesha elizayo. Kwaye umgangatho oqhelekileyo ukususela ekuzalweni ukuya ekuphuhlisweni nasekuvuthweni kancinci kancinci awusebenzi kangako. Ingakumbi kushishino lwe-IT, naluphi na ubuchwepheshe buhlala buphucuka kwaye buziguqula, njengoko kunjalo nge-Serial Attached SCSI (SAS). Njengomlandeli we-SCSI ehambelanayo, i-SAS specification ibikho kangangexesha elithile.
Kwiminyaka edlulileyo kwi-SAS, iinkcukacha zayo ziye zaphuculwa, nangona iprotokholi esisiseko igciniwe, ngokusisiseko akukho tshintsho lungako, kodwa iinkcukacha zesixhumi se-interface yangaphandle ziye zatshintsha kakhulu, olu luhlengahlengiso olwenziwe yi-SAS ukuze luhambelane nemeko yemarike, ngala manyathelo okunyuka ukuya kwiikhilomitha eziliwaka" aphucukileyo ngokuqhubekayo, iinkcukacha ze-SAS ziye zakhula ngakumbi. Izixhumi ze-interface zeenkcukacha ezahlukeneyo zibizwa ngokuba yi-SAS, kwaye utshintsho oluvela kwi-parallel ukuya kwi-serial, ukusuka kwi-parallel SCSI technology ukuya kwi-serial connected SCSI (SAS) technology lutshintshe kakhulu inkqubo ye-cable routing. I-SCSI yangaphambili ehambelanayo ibinokusebenzisa i-single-end okanye i-differential kwiitshaneli ezili-16 ukuya kuthi ga kwi-320Mb/s. Okwangoku, i-SAS3.0 interface exhaphake kakhulu kwicandelo lokugcina izinto zoshishino isasetyenziswa kwimarike, kodwa i-bandwidth ikhawuleza kabini kune-SAS3 engakhange iphuculwe ixesha elide, eyi-24Gbps, malunga ne-75% ye-bandwidth ye-PCIe3.0×4 solid-state drive eqhelekileyo. Isixhumi samva nje seMiniSAS esichazwe kwinkcazo ye-SAS-4 sincinci kwaye sivumela uxinano oluphezulu. Isixhumi samva nje seMini-SAS silingana nesiqingatha sobungakanani besixhumi sokuqala se-SCSI kwaye silingana ne-70% nobukhulu besixhumi se-SAS. Ngokungafaniyo nentambo yokuqala ye-SCSI parallel, zombini i-SAS kunye neMini SAS zineendlela ezine. Nangona kunjalo, ukongeza kwisantya esiphezulu, uxinano oluphezulu, kunye nokuguquguquka okungakumbi, kukwakho nokwanda kobunzima. Ngenxa yobukhulu obuncinci besixhumi, umenzi wentambo yokuqala, umdibanisi wentambo, kunye nomyili wenkqubo kufuneka banikele ingqalelo esondeleyo kwiiparamitha zokuthembeka kwesignali kuyo yonke indibano yentambo.
Ayizizo zonke izixhobo zokudibanisa iintambo ezikwaziyo ukubonelela ngemiqondiso yesantya esiphezulu esemgangathweni ukuhlangabezana neemfuno zokuthembeka kwesignali kwiinkqubo zokugcina. Izixhobo zokudibanisa iintambo zifuna izisombululo ezikumgangatho ophezulu nezingabizi kakhulu kwiinkqubo zokugcina zamva nje. Ukuze kuveliswe izixhobo zokudibanisa iintambo ezizinzileyo nezihlala ixesha elide, kufuneka kuqwalaselwe izinto ezininzi. Ukongeza ekugcineni umgangatho womatshini kunye nokucubungula, abayili kufuneka banikele ingqalelo kwiiparameter zokuthembeka kwesignali ezenza ukuba iintambo zesixhobo sememori esikhawulezayo sanamhlanje zibe nokwenzeka.
Inkcazo yokuthembeka kwesignali (Yeyiphi isignali epheleleyo?)
Ezinye zezona parameter ziphambili zokuthembeka kwesignali ziquka ukulahleka kokufakwa, i-crosstalk ekufutshane neye-far-end, ukulahleka kokubuya, ukuphambuka kwe-skew ye-difference pair ngaphakathi, kunye ne-amplitude ye-difference mode ukuya kwi-common mode. Nangona ezi zinto zihambelana kwaye zichaphazela enye nenye, singaqwalasela into enye ngexesha ukuze sifunde impembelelo yayo ephambili.
Ukulahleka kokufakwa (Iiparameters zefrikhwensi ephezulu Iziseko 01- iiparameter zokunciphisa)
Ukulahleka kokufakwa kukulahleka kwe-amplitude yesignali ukusuka kwisiphelo sokudlulisa sentambo ukuya kwisiphelo sokwamkela, esihambelana ngqo ne-frequency. Ukulahleka kokufakwa kuxhomekeke kwinani lentambo, njengoko kubonisiwe kumzobo wokunciphisa umbane ongezantsi. Kwizinto zangaphakathi zomgama omfutshane zentambo ye-30 okanye ye-28-AWG, intambo esemgangathweni olungileyo kufuneka ibe nokuncitshiswa okungaphantsi kwe-2dB/m kwi-1.5GHz. Kwi-6Gb/s SAS yangaphandle esebenzisa iintambo ze-10m, intambo ene-avareji yomgca we-24 iyacetyiswa, ene-avareji ye-13dB kuphela kwi-3GHz. Ukuba ufuna umda wesignali ongaphezulu kwizinga eliphezulu ledatha, chaza intambo ene-avareji encinci kwi-frequency ephezulu kwiintambo ezinde.
I-Crosstalk (IiParameters ze-High Frequency Basics 03- Iiparamitha ze-Crosstalk)
Ubungakanani bamandla adluliselwa ukusuka kwisignali enye okanye isibini somahluko ukuya kwesinye. Kwiintambo ze-SAS, ukuba i-crosstalk ekufutshane (NEXT) ayincinci ngokwaneleyo, iya kubangela uninzi lweengxaki zekhonkco. Umlinganiselo we-NEXT wenziwa kuphela kwisiphelo esinye sentambo, kwaye bubungakanani bamandla adluliselwa ukusuka kwisibini sesignali yokudlulisela imveliso ukuya kwisibini sokwamkela ingeniso. I-crosstalk ekude (FEXT) ilinganiswa ngokufaka isignali yesibini sokudlulisela kwelinye icala lentambo kwaye kujongwe ukuba mangakanani amandla aseleyo kwisignali yokudlulisela kwelinye icala lentambo.
I-NEXT kwindibano yentambo kunye nesixhumi idla ngokubangelwa kukwahlulwa kakubi kweepayina zomahluko wesignali, okunokubangelwa ziindawo zokukhupha kunye neeplagi, ukumiswa okungaphelelanga, okanye ukuphathwa kakubi kwendawo yokuphela kwentambo. Umyili wenkqubo kufuneka aqinisekise ukuba umdibanisi wentambo ujongene nale micimbi mithathu.
Iigophe zokulahleka kwiintambo eziqhelekileyo ze-100Ω ezingama-24, 26, kunye nama-28
Ukuhlanganiswa kwentambo esemgangathweni olungileyo ngokuhambelana ne-“SFF-8410-Specification for HSS Copper Testing and Performance Requirements” elinganiswe yi-NEXT kufuneka ibe ngaphantsi kwe-3%. Ngokuphathelele i-s-parameter, i-NEXT kufuneka ibe ngaphezulu kwe-28dB.
Ilahleko Yokubuyisela (IiParameters Eziqhelekileyo Eziphezulu Ezisisiseko 06- Ilahleko Yokubuyisela)
Ukulahleka kokubuya kulinganisa ubungakanani bamandla abonakaliswa kwinkqubo okanye kwintambo xa isignali ifakwa. La mandla abonakalisiweyo anokubangela ukwehla kwe-amplitude yesignali kwisiphelo sokwamkela intambo kwaye angabangela iingxaki zokuthembeka kwesignali kwisiphelo sokudlulisa, nto leyo enokubangela iingxaki zokuphazamiseka kwe-electromagnetic kwinkqubo kunye nabayili benkqubo.
Le lahleko yokubuya ibangelwa kukungafani kwe-impedance kwindibano yekhebula. Kuphela kukuyiphatha ngononophelo olukhulu le ngxaki apho i-impedance yesignali ingatshintshi xa idlula kwi-socket, i-plug kunye ne-wire terminal, ukuze utshintsho lwe-impedance luncitshiswe. Umgangatho we-SAS-4 wangoku uhlaziywe kwixabiso le-impedance le-±3Ω xa kuthelekiswa ne-±10Ω ye-SAS-2, kwaye iimfuno zeentambo ezisemgangathweni olungileyo kufuneka zigcinwe ngaphakathi kokunyamezela okuqhelekileyo kwe-85 okanye i-100±3Ω.
Ukuguqulwa okugobileyo
Kwiintambo ze-SAS, kukho ukuphambuka okubini okugoso: phakathi kweepawundi ezahlukeneyo nangaphakathi kweepawundi ezahlukeneyo (uphawu lomahluko wethiyori yokuthembeka kwesignali). Ngokwethiyori, ukuba imiqondiso emininzi ingeniswe kwelinye icala lentambo, kufuneka ifike kwelinye icala ngaxeshanye. Ukuba ezi mpawu azifiki ngaxeshanye, le nto ibizwa ngokuba yi-skew distortion of the cable, okanye i-delay-skew distortion. Kwiipawundi ezahlukeneyo, ukuphambuka okungaphakathi kwepawundi yomahluko kukulibaziseka phakathi kweentambo ezimbini zepawundi yomahluko, kwaye ukuphambuka okuphakathi kweepawundi zomahluko kukulibaziseka phakathi kweeseti ezimbini zeepawundi zomahluko. Ukuphambuka okukhulu kwepawundi yomahluko kuya kwenza ibhalansi yomahluko wesignali edluliselweyo ibe mandundu, kunciphise ubukhulu besignali, kwandise i-jitter yexesha kwaye kubangele iingxaki zokuphazamiseka kwe-electromagnetic. Umahluko wentambo esemgangathweni olungileyo kwi-internal skew distortion kufuneka ube ngaphantsi kwe-10ps.
Ixesha lokuthumela: Novemba-30-2023
