Niaj hnub no cov tshuab khaws cia tsis yog tsuas yog loj hlob ntawm terabits thiab muaj cov ntaub ntawv hloov pauv ntau dua, tab sis kuj xav tau lub zog tsawg dua thiab tuav cov hneev taw me dua.Cov tshuab no tseem xav tau kev sib txuas zoo dua los muab kev hloov pauv ntau dua.Cov neeg tsim qauv xav tau kev sib txuas me me los muab cov ntaub ntawv tus nqi xav tau hnub no lossis yav tom ntej.Thiab ib qho kev cai txij thaum yug mus rau kev loj hlob thiab maj mam loj hlob yog nyob deb ntawm ib hnub ua haujlwm.Tshwj xeeb tshaj yog nyob rau hauv kev lag luam IT, txhua yam thev naus laus zis niaj hnub txhim kho thiab hloov kho nws tus kheej, ib yam li Serial Attached SCSI (SAS) specification.Raws li ib tug successor rau parallel SCSI, SAS specification tau nyob ib ncig ntawm lub sij hawm.
Hauv xyoo uas SAS tau dhau mus, nws cov kev qhia tshwj xeeb tau txhim kho, txawm hais tias cov txheej txheem hauv qab tau khaws cia, feem ntau tsis muaj kev hloov pauv ntau dhau, tab sis cov kev qhia tshwj xeeb ntawm cov khoom sib txuas sab nraud tau hloov pauv ntau, uas yog kev hloov kho los ntawm SAS hloov mus rau ib puag ncig kev lag luam, nrog rau cov "cov kauj ruam nce ntxiv mus rau ib txhiab mais" kev txhim kho tas mus li, SAS specifications tau dhau los ua neeg paub tab.Cov kev sib txuas sib txuas ntawm qhov sib txawv yog hu ua SAS, thiab kev hloov pauv ntawm kev sib txuas mus rau serial, los ntawm kev sib txuas SCSI thev naus laus zis mus rau serial txuas nrog SCSI (SAS) thev naus laus zis tau hloov pauv txoj kev xa xov cable zoo heev.Yav dhau los thaum uas tig mus SCSI tuaj yeem ua haujlwm ib leeg-kawg lossis sib txawv tshaj 16 txoj hauv kev mus txog 320Mb / s.Tam sim no, SAS3.0 interface uas muaj ntau dua nyob rau hauv kev lag luam chaw cia khoom tseem siv nyob rau hauv kev ua lag luam, tab sis cov bandwidth yog ob zaug ceev li SAS3 uas tsis tau hloov kho rau lub sijhawm ntev, uas yog 24Gbps, txog 75. % ntawm bandwidth ntawm PCIe3.0 × 4 solid-state drive.Qhov tseeb MiniSAS connector piav nyob rau hauv SAS-4 specification yog me dua thiab tso cai rau kom ceev dua.Qhov tseeb Mini-SAS connector yog ib nrab ntawm qhov qub SCSI connector thiab 70% qhov loj ntawm SAS connector.Tsis zoo li tus thawj SCSI parallel cable, SAS thiab Mini SAS muaj plaub txoj kab.Txawm li cas los xij, ntxiv rau qhov nrawm dua, qhov nrawm dua, thiab hloov tau yooj yim dua, kuj tseem muaj qhov nce hauv qhov nyuaj.Vim tias qhov me me ntawm cov khoom sib txuas, cov chaw tsim khoom qub cable, cable assembler, thiab cov neeg tsim qauv yuav tsum tau ua tib zoo saib xyuas cov teeb meem kev ncaj ncees thoob plaws hauv kev sib dhos cable.
Tsis yog txhua tus cable assemblers muaj peev xwm muab high-speed high-speed signals kom tau raws li cov kev xav tau ntawm lub teeb liab kev xav tau ntawm cov tshuab cia.Cable assemblers xav tau cov kev daws teeb meem zoo thiab tus nqi tsim nyog rau cov tshuab khaws cia tshiab.Txhawm rau tsim kom muaj kev ruaj khov, ruaj khov siab ceev cable sib dhos, ntau yam yuav tsum tau xav txog.Ntxiv nrog rau kev tswj xyuas qhov zoo ntawm machining thiab kev ua haujlwm, cov neeg tsim khoom yuav tsum tau ua tib zoo saib xyuas cov teeb liab kev ncaj ncees uas ua rau hnub no lub siab ceev cov khoom siv cables ua tau.
Lub teeb liab kev ncaj ncees specification (Lub teeb liab twg ua tiav?)
Qee qhov tseem ceeb ntawm cov teeb liab kev ncaj ncees suav nrog kev poob, ze-kawg thiab deb-kawg crosstalk, rov qab poob, skew distortion ntawm qhov sib txawv khub sab hauv, thiab lub amplitude ntawm txawv hom rau hom hom.Txawm hais tias cov xwm txheej no muaj kev cuam tshuam thiab cuam tshuam rau ib leeg, peb tuaj yeem xav txog ib qho ntawm ib lub sijhawm los kawm txog nws qhov cuam tshuam loj.
Insertion poob (High frequency parameters Basics 01- attenuation parameters)
Qhov kev poob qis yog qhov poob ntawm cov teeb liab amplitude los ntawm qhov kawg ntawm lub xov tooj mus rau qhov kawg tau txais, uas yog ncaj qha proportional rau zaus.Qhov kev poob qis kuj nyob ntawm tus lej xov tooj, raws li qhia hauv daim duab kos duab hauv qab no.Rau luv luv nyob rau hauv lub Cheebtsam ntawm ib tug 30 los yog 28-AWG cable, ib tug zoo zoo cable yuav tsum muaj tsawg tshaj li 2dB / m attenuation ntawm 1.5GHz.Rau sab nraud 6Gb / s SAS siv 10m cables, ib lub cable nrog qhov nruab nrab kab ntsuas ntawm 24 yog pom zoo, uas tsuas muaj 13dB attenuation ntawm 3GHz.Yog tias koj xav tau cov teeb liab ntau dua ntawm cov ntaub ntawv ntau dua, qhia ib lub cable nrog tsawg attenuation ntawm high zaus rau cov cables ntev.
Crosstalk (High Frequency Parameters Basics 03- Crosstalk parameters)
Tus nqi ntawm lub zog kis los ntawm ib lub teeb liab los yog qhov sib txawv khub mus rau lwm tus.Rau SAS cables, yog tias qhov ze-kawg crosstalk (Tom ntej) tsis yog me me, nws yuav ua rau muaj teeb meem txuas feem ntau.Tom ntej no txoj kev ntsuas yog ua nyob rau ntawm ib kawg ntawm cable, thiab nws yog tus nqi ntawm lub zog kis los ntawm cov zis kis tau tus mob teeb liab khub mus rau lub input txais khub.Far-end crosstalk (FEXT) yog ntsuas los ntawm kev txhaj tshuaj rau qhov sib kis ntawm ib qho kawg ntawm cable thiab saib seb lub zog npaum li cas ntawm cov teeb liab kis mus rau lwm qhov kawg ntawm lub cable.
Tom ntej no nyob rau hauv lub cable sib dhos thiab connector feem ntau yog tshwm sim los ntawm kev tsis zoo ntawm kev sib cais ntawm lub teeb liab sib txawv khub, uas tej zaum yuav tshwm sim los ntawm qhov hluav taws xob thiab plugs, tsis tiav grounding, los yog tsis zoo tuav ntawm lub cable termination cheeb tsam.Tus tsim qauv tsim qauv yuav tsum xyuas kom meej tias cov khoom siv cable tau daws peb qhov teeb meem no.
Poob nkhaus rau 100Ω cables ntawm 24, 26, thiab 28
Zoo zoo cable sib dhos raws li "SFF-8410-Specification rau HSS Copper Testing thiab Performance Requirements" ntsuas tom ntej yuav tsum tsawg dua 3%.Raws li qhov s-parameter muaj kev txhawj xeeb, NEXT yuav tsum siab dua 28dB.
Rov Los Poob (High Frequency Parameters Basics 06- Rov Los Poob)
Rov qab poob ntsuas tus nqi ntawm lub zog cuam tshuam los ntawm lub kaw lus lossis cable thaum lub teeb liab raug txhaj.Qhov kev xav ntawm lub zog no tuaj yeem ua rau poob ntawm cov teeb liab amplitude ntawm qhov kawg ntawm lub cable thiab tuaj yeem ua rau muaj teeb meem kev ncaj ncees ntawm qhov kawg, uas tuaj yeem ua rau muaj teeb meem electromagnetic cuam tshuam rau lub kaw lus thiab cov neeg tsim qauv.
Qhov kev poob rov qab no yog tshwm sim los ntawm impedance mismatches hauv kev sib dhos cable.Tsuas yog los ntawm kev kho qhov teeb meem no nrog kev saib xyuas zoo tuaj yeem ua rau lub impedance ntawm lub teeb liab tsis hloov thaum nws dhau los ntawm lub qhov (socket), ntsaws thiab xaim davhlau ya nyob twg, kom qhov kev hloov pauv impedance tsawg.Tus qauv SAS-4 tam sim no tau hloov kho rau tus nqi impedance ntawm ± 3Ω piv nrog ± 10Ω ntawm SAS-2, thiab cov kev xav tau ntawm cov kab hluav taws xob zoo yuav tsum tau khaws cia nyob rau hauv qhov nominal kam rau ua ntawm 85 lossis 100 ± 3Ω.
Skew distortion
Nyob rau hauv SAS cables, muaj ob skew distortions: ntawm txawv khub thiab nyob rau hauv sib txawv khub (qhov sib txawv teeb liab ntawm lub teeb liab kev ntseeg siab).Hauv txoj kev xav, yog tias ntau lub teeb liab nkag mus rau ntawm ib kawg ntawm cable, lawv yuav tsum tuaj txog ntawm lwm qhov kawg ib txhij.Yog tias cov teeb liab tsis tuaj txog tib lub sijhawm, qhov tshwm sim no hu ua skew distortion ntawm cable, lossis ncua-skew distortion.Rau qhov sib txawv khub, qhov skew distortion hauv qhov sib txawv khub yog qhov ncua ntawm ob lub xov hlau ntawm qhov sib txawv khub, thiab qhov sib txawv ntawm cov khub sib txawv yog qhov ncua ntawm ob pawg ntawm qhov sib txawv khub.Qhov loj skew distortion ntawm qhov sib txawv khub yuav ua rau qhov sib npaug sib npaug ntawm cov teeb liab kis tau tus mob, txo cov teeb liab amplitude, nce lub sij hawm jitter thiab ua rau muaj teeb meem electromagnetic cuam tshuam.Qhov sib txawv ntawm qhov zoo zoo cable rau sab hauv skew distortion yuav tsum tsawg dua 10ps
Post lub sij hawm: Nov-30-2023
