Am33c93a Scsi-bus Interface Controller

FI

AmSSCggA EnhancedSC$l.Bu$lnterfaceGontroller; DISTINCTIVE CHAHACTEN|STICS I lrrplemonts full SC$lbusfeatures:arbitratbn, disconnsct, reconnsct,paritygenentio rVc{redring on bothdataports,softreset,ard syrrchrotsus datatransfers. r Synchronous offsetsefe(*abJs from I lo l ? bytes, wlthselec{able trensferperiodup to 5 Mbyte#s. r Cornpatible with npst microprocessors lhroughan S-bitdstahrs; supportsbothruulfiplexed ard nonmultplexedaddre$s/data h.ls systerts.Hostbus dataparitycheckingandgenerationis an opti,onal feature. r Canbe useda$a ho$tadaper(SCSfInltiator) or peripheral, adapter(SCSITarget). r Datatransferoptionsincludeprogrammed l/O, :DlVtR, single-byte DMA,burst(multibyte) or direct busaccees(DBABus)transfers.

Advanced Micro Devices

I lrrcludee 48-rnAdriversfor directconnection to the SCSI'bus,. r Burstdatatransfersup to 4096bytes. r Programnrable tineoutfor selectbnand reselection. greatlyreduceintemJptl "Combinatbn'coramands hardlingresponslbilit les. I Special'TranslateAddress'command performsthe Logical-to-Fhysiealaddress,transf atbn. . r Sirqle+5.Vsumly. t Available in 44-pinchrpcarrieror 40-pinDlP. I LowpowerCMOSdesign.

GENERALDESCRIPNON The 33C93Ais a MOS/VLSIdeviceimptemented in AdvancodfvfbroDeviees'CMOSprccess.lt operatss froma single5-Voltsupplyard is avallableln eithera 44-pinchipcarrieror a 40-pindual-in-line package.All inpulsandoutputsareTTLcompatible. The33C93Ais intendedfor usein systemswhhhinterfaceto the $rnaltGompter Sy$em Interface(SC$l) Bus.The33C93Acanoperatein boththe initiator{typically,a hostcomputersystem)ard the target(lypbally, a peripheral device)SCSIhls roles. Whenusedin the hostsystem,the SgCgOA interfaces to boththe ho$tbus ard the scst hrs. To performa SCSIoperation,the hostprw-essorissueea somiiland to the 33C93Ato select the desiredTargel. The 33c93Athsnait$$atesforthescsl hrs andselsc*sthe ceripheraluRit.lf it fails to g,gtthe bus becaueeol a Cevicewith hfiher prbnty, it continuestryingard rcti'ies the hostwhenit hassuccoeded by gengrafing an nterrupt.At this point,the 33C93Ais operatingin the nitiatorrols. When the periphsralrequestsa SCSI rcmmandfromthe host,lho 33CggAreceivsgthe requestandgeneratesanotherinterruptto the ho$t,The rcst respondsto lhis interruptby issuinga "Transter

}.ffcdirn

t118gt'

crp Odc: Juno 1S

F.{L A

ln

lnto"commandard supplyingSG$lsemmandbytesto the33c93A.The33C93Atransfers the SCS|comrnand to the perpheral,ard thenwaitslor the nextbusphase request.Thisprooos$cor$inuesuntilall $CSl irrfonnatbn includirqdata,status,and messageshavebesn lransferred. Ths 33G9-3A alsooffershigh-levelSelect-ard-Transfer commar,ds whicheliminate the interrupthardlingotlrer. wiserequirodbetweeneachSCSIbusphase. Whenthe SBC93Ais usedin a peripheralsystem,the SSOggA witloperateprimarilyin a Targetrole. lt interf*cos wilh ,il bcal proces$orand the SCSIbus in this environnw$ iust aS it does when used as a host adapter.The Target-rolecomrnard set enablesthe SgC,SSAto requesteach$C$l busphaseindividually or to ssqrsnce the SCSI bus phases automaticaily throughtheueeof combination @rnmands. ThelSSCSBA hasan internalmbromntroller, a register task file, and SCSI interfacelogic.This architecture $uppoft$, hth tiglxtcontrolof the protocolfor rtonstarldardSC$l implernentations, as well a$ a handslree modefor standard$CSl applications.

rilcfiro

*m&reff}A

SI,$SK DIAGRAii $c$l Bus

Intsrnaf Bus

cs m, TvE,D7-Do,Dp

DRO

n\cl(

&3r

An$3SSA

COTINE

'OnqR*SfS

l5r':i'l'+r'ir

*rhPIH CHIP9ry'iEn

BB Slgrsa$lH,lU{Es 6

4

5

3

|

2

4

4l{e41

SEL

T

cu(

8

38

ffi

DRQ

I

97

sD6

DACK

10

38

(HALr)

DP

11

S

sD5

12:

34

si

-....----

INTRO

o

g

40 g

.

3Hl

$D3

s

ffi

91

GND

S

S-r ffi

DO

1A

ol

1

D2

15

Dg

1

6

D4

17 19 19 20 z't U

29 s 23 24 ?5 e,6 27 28 ./

4

G}ID

E t q 9 t8ls lH'$lH 6 0 g

Nots: Pingln parentheseo,sl|,br'te*tpurpw

on$, ard shouldbs left unmnnoctedfor mr,rnalchb op

4&FIN DIP tffi

msc

lr

40

---+

GND -

e4 ffi ffii

ATN

sffi GND sD7

CLK

6m

Enffi NTrc DO D1 D2 D3 D4 D5 D6

v7 AO GND

vcc NF Tffi

10 11 1g rg 14' 15 1S

91 30 20 e8 27 26 25

\7

zrt

18 1S 20

23 2n 21

fimeffi*

sDs ffi ffi ffie 5Dn Gf\tD s01 sD0 SF ALE ffi

WE 6

ORDERINGINFOHMATION standardProductg .^!,^r-,^ :- sewral ^^. - packages AtttDstandardproduc{sare availabb in andoperatingraRg6s.Theordernumber(V is formedby a combination of: a 1levbeNumber ' b. Speed.Optlon (if appllcable) q. PackageTypc d. leqperatlrre Range e. Optlonal Proceselhg -2A

Atf33C93A

J

C e. OPTIONALPROCESSNC Bfank. Standardprocossing d. TEIIPERATURERANGE C - Comrnercial (0 to+70€) c. PACKAGEWpE p- 40-PinPlasricDtP(pD O40) .; - 44-PinPlasticLeadedChlpCarbr (PL044) b. SPEEDOPnOill -16 - 16 frrfHz *20.20 MHz

DEVtCgtl UItfBER/DESCR|mON Am33C93A

Valld Comblnatlons

AMg3C93A-16 AtrI$CagA-20

43f

JC, PC

: ValH Comblnsfonc Vafid Combinatiolq.llstco$qqptbns plannedto be supportedin volumefor thls devb. Consultthe focalAuO sateso*iceto confirm-iviii"niiity"iliijirt valid corn,binations, to checkon newfyrelsassd comUinaidns, ari,l to irt*airr additbnaldataon AMD'gstandardmil,-itary gradsproouctJ.

AmStCgSA

PI}I DESCRIPTPNS

PrucaucurlDf A'.lntsrfa& l/o

Hrlnr

Functbn .

CLK

8-20MHz $quersnrevechck

frH

Resetb an active-loryy inputwhkrtrforcesthe 33Cg{tAintoan kile state.All SCSIs[nals areforced to the negatedstste.

INTHO

o

lntentpt Rcqueetto externalmbrryroceemr indietes a sorffilsrd oompbthltermln*bilior a needto servb the SCS|interf*e. Readingthe SCSISTATUSrggbterdears thisbit.

AE

uo (TRt€rnrel

ReBdEnableie an astive-lqr irput s'fiFft b usednmt ffi'to read,srsgbtoror wilhDTCRto{oos-ss thg DATAregistorln DMArnoda.ln DBABus mods,lt b uEedas an ouFut to readdsta frornE esdor buffer.

VfE

vo

WriteEnableis an .a{iy-grlowinputwJrichp ueedw}th6ts

wrltea lggreteror withDTERu Wq

(TRI-STATE) the-DATArqister in DMAmod;. h DBABusmode,it is ueedeesn d.lttrfi to wrftedateto e *sctqr buffer.

f

f

i

l

Chb Selectb an ac'live-lowinputwhictrqu{ities_nE and VFEwhen accoesfig,,&fagisrrr,,....W sfnal mustbe lnacillveduringa DMAcyde 1ffi wtbq in D[fA end BurgtDMArude, Er fifiil rctivo in DBABus rnode).

AO

Addresspn A0 is usedto rccess the intemalregisterslor non-multlplexed ddress/dda bus (1.e.the ALE pin b groundedl.The addreesof the dee$i€dregleterb hdsd into ths AffiAESS registerdurlnga writecy'rSe withA0-0. Thoael€d-€dregibierb thsn mespd wlrenrd0-l,

ALE

AddressLatchEnabteis usedtor multiplexod ddree,sffafebusto bad the ad&eeeof ths desir€d 33C93Aregisterfromthe dala bus. il indirscfaddressingb b bs us€d,the ALE pin shouHbe grounded.Ses thg descriptbnof ths AODRE$Sragietor,h E mnplso dis€r*ssbnd dirw{ ard indirec{addressing.

gffi-d.nowledge input used for intefiacingto an exlernalDMA sfiroller te€. 8834. Whgn DEEK Uo Sfr,6Ris bw, all bue trandere are to#nm t[e DATArry$*terregardhssof ths'snter$$ of ttrs 1Rffil (oPENDRATN)

ADDRESSregi$er.ln DBA8us mode,thispln furdbns as a RAMcfripselestouprt ts altnr the gitcgs to amessa socilorbuffer.HE frndWE areoutprrtswhen'Fffi FAsr chp $elect)is af,*hm. Sineethis pin can be an opgndruin6ufput,a pullup reEistormay be roquiredurtrenoperatingi,n

Effi, u0 D*tr rsgueatb enouput whenintedacingb ar sxtsmElDtlA contlg!:bLandnn irput whenin AM (DRQI, {OpENDRAfNI Bus rnode.Whenussdwithan extsmalDMAontro$er,,ffi ard DIER |onnttp ha;drhrke lor the data-bytstransfe*.,ktBurotrRode,EFE rerrrsinskfrilas bng eothereb date,b traru{ef"ln *M Bus mode,thg SSggg{SlMrns burst$ans5l wh{1SRA is h[h, and whgnSrc is blr, date ffanslereare inhibited,BCSb fals, andlho nF and lt{E outgns cre disabld.,sne thie pln c*n bo an op6ndrainoutput,a pulhtprasbtorrnaybe requiredwhenoporatingln DfrilAor Burctrnode D7*D0

b0

Processordatahrs.

DP

1,{}

D$a Perlty,ussdor$ fcr cfitcklqglssnsrrating Far y dudng6ol* tranglers

SGSI lnterface

rTfr

lro

Func,tbn

uo

Ifffi-io qn outpr* in the iniikior rele end an lngn in thn larget mb. li is us€d to irdlcate ths ATTEI{TONconditbn.

Tffi

Iffi is an outprrtin the iniihtot rolEand an input in the larget rob. lt is usedto irdicats En acknqwbdgertentlor a REQ/ACKdatatransferhand*hqke

mffi

uo

is an input ln the initidor rob and an output in the taryet role. lt is assertedduringa f MESSAGEphase.

C,D'

uo

CO is an i:nputin the initiatorrole and an outputin the target1016. lt is usedto irdicatewh*h* CONTROLor DATAinforrr,rEtion is on the $Cgl databus.

HE.6

vo

HE6 is an inputin the initiatorroloandanoutputin the targetrole.I indicatssa requetlor a REQI AGKdatatransfer.

tnrffi*

ikl|fi

$CSl lnterface(Cont) l{anr

UO

Fune&r

bo

vo

16 is an irput in the initiatorrcle and an outputin the tflget rde. lt controb the dkectbn d data movem€nton the scsl databus with reopectto an lniliator.

sE'GsD'7 vo

SCSIdatabus.

SDP

yo

SCSIdatabusparitys[nal.

BSY

uo

EW is assertedwhenthe 33Cg3Ab attemptirgto albtr*e lor the SCSfbusor whenconneaed as a Target.

ffi

b('

SsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssI is assertedwhenthe SICgBAis afernsing to sehct or resslecianotherSCSIdwb.

fiX***********************************************************************************************************ofe; All pins have open4rain output drivers.

AmSSCSIAREGISTERS

ReglsterMAP

ffofe8.'

l,

Rt/w

ReglsterAccesscd

R w RW R/W R/W R/W R/W R/W R/W R/W R/W FUW FUW Rtw R/W RtW R/W R/W M,1, R/W R/W R/W R/W R/W FUW R R/W R/W

AUXILIARYSTATUSREGISTER ADDRESSREGISTER OWNID REGISTER CONTROLREGISTER TIMEOI'TPERIODREGISTER TOTALSECTORSREGISTER TOTALHEADSREGISTER TOTALCYLTNDEHS REG|STER(M$B) TOTALCYLTNDERS REGTSTER (LSB) LOGTCAL ADDRESS(MSB) LOGTCAL ADDRESS(2ND) LOGTCAL ADDRESS(3RD) LOGTCAL ADDRESS(LSB) SECTORNUMBERREGISTER HEADNUMBERREGISTER oYL|NDERNUMBER(MSB)REGISTER cYLINDERNUMBER(LSB)REGTSTER TARGETLUNREGISTER COMMANDPHASEREGISTER SYNCHRONOUS TRANSFER REG]STER TRANSFER COTNT REGTSTER (MSB) TRANSFER COUNTREGTSTER (zNDByrE) TRANSFER COUNTREGTSTER (LSB) DESTINATION ID REGISTER SOURCEID REGISTER SCSISTATUS COMMAND REGISTER DATAREGISTER

Addnrr (HEYI

xx rcDB SIZE ,CDB lST ,CDB zND ICOB 3RD &DB 4TH 'cDB sTH ,CDB 6TH /CT}B 7TH ICDB 8TH ICIIB 9TH rcDB loTtl ,CDB1lTH rcDB 12TH

)fi 00 01 a2 03 04 05 06 07 08 09 OA 08

0c OD OE OF 10 11 12 1g 14 15 16 17 18 19

Afl unusedtits of a deflnd registerare rcseruedaN mustfu zero.

2. Readingan undefinedor unavailabteregisterresurfsin an all+lnesdata bus outrlul

Rqistor addressesaredeterminedby the ADDRESSregisterbits ARTthroqh AR1. Wlen usinga multiplexedaddress/data buswith ALE,theAA pinis igrwrd andthe ADD1ESSregister with ALE.ln thismde, the AUXILIARYSTATUSregisteris mapped-athex tF. SeePage 14for a descriptionof how resetaffectsthe internalregistera.

{.38

Am3{893A

i;

1

li 4

r

'i*\-*\g,;:ii;i,

Regl*ter l}iffi crlptlons AUXILIARYSTATUSREGISTERS The AUXILIARYSTATUS register is a read-only AUXILIARY STATUSrryiSer mayb? aFessedat any regbterwhichcontainsganeralstatusinformatbnrpt time,exceptduringDMAaccessss(ffiR assertedin drsctry associatedwith the intemrptmndition. The DMAEurstnpde or DnQ as$ertedin DBAbus u}. 0

DATABUFFEHREADY PARIW ERROR !,fotUscd lSt U$ed COI'IUAhDN PROGRE$SBUSY BUSY LASTCOMMANDilSNORED INTERRUPT PENOI}€ .

Btt

ilame

lt's$sl*

,

De*rlpton

DBR

DATABUFFERREADYis ussddurirqprcgrammed ll0 ts lndicateto theprocessoiwhsther or rpt the DA;[A registeris availablefor ruadirg or writing. DurtngSend or Transfer comrnardswhichtransrnitdataovertho SCS|bus,the DBRbit is sel whenthe 33G93Ais redy b takoa bytefromthe tpst; the bit is re6etwhentho prooessor writesthe byteto the DATAregister.DuringReceiveor Trsnsfsrcom:mands whichrecelvedats ovsr ths SCSI bus,the DBRis set whena byteis recelved;',ft ie r€setwhenthe procassorreadsthe byte fromthe DATAregisler.

PE

PARIW ERRORstatusirdicatesthet ,u,onpfiritywas detecfiedon * dda b$e rec-eivod duringan intormatbntransfer,Parityis checkedon data reseivEdfromthe b$ busfuring translersout to the SCSIbus ard is cheslffi ori data,reoeived frurnthe $OS]bus drnr€ transfersoutto ths hostbus.Detection of a padryerTorwillsetthePE statusbit regardless ol the stateof ths HHPor H$PbitslntheCOfiITftOLregister.Tlls PEbit is clsarsdwhena new commandis issued.

clP

GOMMANDlN PROGRESS, when sel, irdicatesthat the SSGggAls interpretingthe tast @mmandenteredintothe'COMMANDregflgtsr ard thereforethis regisleris unavailable. tfilhenthis bit ls reset,a sn1land maybe writtenb the COMMANDreglster

BSY

BUSYindbatesthat a Level ll commardl$ ,cunentlyexecrrttqgard rtherefsreonfy the COMMANDregislsr{whenCIP = 0}, the ,'[i$TAregiiter,and the AUXILIARYSTATU$ reg,isteraFs'aoceasibfety the host. A LEvelll cornrnandr€y rpt,bs written lo ths registsrwhoathisbit is one. COMMAND

LCI

I-.AST IGNORED COMMAND irdbatesthata comrnand wasissuedby the fp$ iustpriorto or @ncunentwitha perdinginterrupt,ard thereforethe @mmardwlit be ignored.

INT

INTERRUPT PENDING indlcates thatths INTRQprnis assefied.Thehostshouldreadthe SCSISTATUSregisterto clearINTROprhr to issuirganycommaruds.

AmS$ffi8^

4"$?

AOORESgNE$STEH The ADDRESSregisterb a writeonV regbter whbh ffintains the add,ressof ths registorto be accs$sod. Regi$ersin ths 33cggAmaybe messed in oneof two ways: . Directaddressir€{nnrltiplexed addresydalahrgses). In directaddressirg,the fallirg e€s of the ALE sfinat is used to fatch the addrus ifito ths ADDRESSregister.The A0 pln shouH be connectedto grouncwhenueirg thb meilrod.TheALE is typballythentoltowedby the F aruCWE or FE sQnab that accessths selectedregister,Alm, ln directackfressirg,the AUxtLtARySTATUSregister is bcatedat addresslF hex. . lrdirest addressing(separateaddress/&ta busses).In irdlrect addressilrg, the regisleraccessis perfornd in tws separdecyctes.This mettprl is enabled by dtachltlg ALE to ground. First, the ADDRESSregisteris ba@ by perforfniqgo write of the desirsdaddressto the ggCggAtWE-anCCS assertedtwith-A0-0.Thsnlhe registeris amssed by assertirq6 and WE or FE,-withAO-t A|so, fofftnrtirqsvsry accesswlth A0-1, fiE ADDRESS regislerwlll automaticallyincrementto polntat the yuiththe exceptlonof the folknvirq 1ten register, hcatbns: AUXILIARYSTATUS regbter, DATA register,ard the coMMAND register.fn lndirect adcfressing, tho AUxtLtARy STATUSregisteris accsssod by pertormirg a red (eS and HE assefted)withA0=0.

owr{tD/cDB $tzEnEGSTEn

The owN IDrcDBslzE register,in its firct mode,oontains botbrhe e@ to 6t ne 33c93A on lhe sCsr bus and several@rtrot bits that are used to initielly cort'lgurethe dwbe furirq the "Reset' comrnard. Thesebits mntrol 'advarrcedfeature'selectbn,host tus panly enabb, ard selectionof the divlsorfor the inprt cbdc fn ile $eoord rrnde {whendanced featuresareenabfed,segB.io), thisregisteris useddurlrq the eortbinatbn cornrnardsto seecifyttlg scsr cDB size if tho onilnard grqrp is urkrpurnto ths gitcggA. In the first mde, this register(as definedberon) is sarrqiledand bgcomcseffectiveonly after a "Reset' commardb issuedto the devbe.This registermustbs lnitialized,ord a "Reset" command rnrst then be lssued.Doirq lhis will set the Scsl bus lD, the cbck divisor, ard operatirq modesbefore arry otfer @mmardsareissued. ln the secondnpde, bits 3-0 of this registerare ussd during the setect-and-Transeraruc wait-for-select smrnards to specfy th€ scsl GomnrardDescrlptor Blocksize tr it b r,pt,a g1otfp0, group i, or group5 cqwnard. This nnde is er€bfodonly when advarped featursearoef$hd tsae p.16).

lD bir0 lD bi,t1 lD bir2 EnableA&anced Fealures F-na!!eHostParity Nd Usod FREAUE}SY SELECTO FREQUENCYSELECTI

rrE6&tEA

grr

Name

0-2

lDn

$CSl lD Bits&2 setlhe SCSIhrs lD nunberthatthe33C93Awillusedurirg arbitrationard selectbn.

EAF

ENABLEADVANCED FEATURES, whensetto one,causesthe 33CggAto enabteceilain advarrced features(seePage16).when thisbit is zero,thosefeaturesaredisabled.

EHP

ENABLEHOSTPARITY,whensetto on€,enables@ parltycheckingon the hostbus;ths PE bit in the AUXILIARYSTATUSregisterwill irdicatdparityenorsdetectedon the host bu8,and th€ HHP Ht in the CONTROLregisterwill be used.Whenthis bit is'zero,no checkingis performed on thehosttus;ths pE bit is notsetwhena parityerroris detectedon ths hosths, andthe HHPblt nr.lstbe setlo zero.NOTE:Parityis ahraysgeneratedon the hostdataparitybit (DP),regardtess of the statoof thisbit.

{-38

DesrlSton

ffi3WSA

Btt

Nurc

v7

F$n

FREQUET'ICY SELECT0-l selsc{tha dvisorlhat b a#ed u ttu il4lutchctr.T}p resrftirg cbck b tsod for dgtatrarilstsrtimfq srd br $SSl hti arffiratbn timir€. Ths tablg beb; d'gorrw cugErtor 9ftryE inputqpd( trequsneyf8lp6$ ar-dthe currceporwrg,,ff{rlsor8. the lrPut slod( t$rsilbo usd, cr SO$lbus,t*nfu ry,ootrbatbrs,nf,ryfFt be gl€il. FIPUTCLOCK FREqUENCY Gfl,{I) 8-10 12.15 f g-20 11

F$l

Flso

0 0 1 t

0 1 0 1

NEgULTilITI DilVTg(H

e s I : U r e d

,Wtp tlffi an ,t MI$Z alcxJ(ru$eEfiputr rp$ &, ssd, ss ffie frsu*frWS6$t bus dgErdg/€lytrry rribHc$6gf,Wdth$ftns, Tln u1y166fw oonryrtfuryd,lc alnrenrrnses, dafi fra,rsf,grr@ fit;

lrtratirnum$CSl TransferRate-

krputClod( Fequeruy lt Clooft$ivi$Er,

r8scl

CONTROLREGISTER Ths COf-{TR*.tgSgr is taed to enabl€fdls#s certainfurrc{bns, - rY'se' rsspons€to parit} as rr'!'f't"'' ' such attentbnwffibn;irfiernrfl rraruffq, ;rfi;t"ir""tfo npdes.

HALTm SC$I.PAR,IWERffiR , . HALTon ATTENTION ]ilTERMEDIATE DISCONNSCT INT ENDINGDISCONNECTIHTERRUPT HALTon HOBTPAHIW,ERROR DMAMode$elecf blt 0 DMAtvlodeSelect,bit1 DMAhrbde$Els€ilbit 2

T'hgHALTon SC$l PARIW EfiROR tst enaWu th* SIlCggAto iriunediatstytsnrltnds I frmfue orTransfersrnrnarld:ff,aparity'orcr,}$ dot Aon an irroonifigSCSIdataby{e.ln rtle tnirtatorrote,terminatbnfte ts 8 scqt Bf,rityoqq cquss tm laR"sn to bs tsftin tfF dlvs state in order to hhhl.rnf,sddilblraf data traneferstREOs)ty tttr frygor; this facilhateserror data tlansrerschedr Barnyev€ry llnotit€ witl the fargot. Svffi* 4@6 bytes,or at the endof ffia rernainirqtransfer@unt,wfrficfrwerls lees.Aglyrp#orpu; : tfirneilerscheckpari$ on sr$ry-r$1to,. ' HA

Ths HALTon nTTENTtOltl'hn rmoe only)o-nebbstho a$cggA to tsffiinets a fin6* Sendor Receivecomrnandif the ITfr inp.rtis as#hed- TG **rv ittdbd;r n*-tnt Iniliatordetecteda parry ero{ while receivir,qdAa fis{n the 3$CCAA:fhs ffi irp,fr i; tsstd bobretheSartof a datatransfer,everyCmObytesil thstransfetcourtris gr".ifd; 4GlSf ar$ etter the ed of ttp transfer.ThE$srutes appryto both syrphlbrpt s ard asymfmrnugtransfers.

IDt

The INTERMF!$IE DISCS,INECT INTERRUPT bit, wfien set, enablestm gftCgSAto .tnd-*t{ele^ a Selec{-ard-Transfer. q|Tot? an 85H ift*p! @mrnandif the Tarryt dismnnectsacmrclirqto the delirredSCSIprotocol.Whenthls bit is reset,rrr lrterrupi-n

gsryr.qlsq i'isognnsct. Thisfeaturd, !y a,vattd whenussdwtthtd RJs#il bffi ffi*i"[*i[ ptsyHsu ry

fdr.overlappodSGSf operatione,fDl b also $s6d to selec*cxocutbn Corminationcornmardsthatservoto redlm froat$yutgrfiorcrhead. $tpm,inTfrffi Bsferts GS$uAI{D$*.p.lEfor rnoredstaifs. &lH.'

Btr

5-7

Hame

Descrlptlon

EDI

Whenthe ENDINGDISCOI{NECT INTERRUPT bit b set,the rOHintemrpturhidrrnrmasy folbwsth$COMMAND COMPLETE messagedrirqthe exocutbnof a Sefecl-ard-Transfar @mrnandwill be suppresseduntilthe Targetdisconnsctslrom the SCSIbus. EDIis aFo used in the Target npde Combinationcommards to ersle chainirq betweentt6se @mmaruds, resultingin reducedhostsySemoverhead.RefertoGOMMANDS p.ts for more details.

HHP

The HALTon HOSTPARITYERRORbit enablesthe glGg3Ato immediately terminatea Serd or Transfer@mrnandlt a parityenoris detededcinan incomlnghoS databyte.Host parltyono18arec{red(edamrding io the rulesfor ched(irqSCSIparilysrrors.Hqrwer, a halton a hoslpantyeror will rpt holdthe Am sbnal assorledwhenan emtroccurs.Fbst paritycheckirqis perfonnedat the sameintervalsas SCSIparilycheckirq.

DMx

DMA MODESELECTbits 2-0 ars used to selectthe DMA ntode ol operatbn,whbfr describesthehosthrs trans{ermodeuseddurir€ DataInor DataOutphases.Thefolbwirq tabledescribesthe diflerentDMArTrodes, ard the staleof thesebitsto selectthem: D[t2

DMl

DHO

DfnAHodc $lqotod POLLEDMODE,or no DMA en$led, All date phase trangfersere performedby pollingfor DBR in the AUXILIARYsTARts regbter,and thenwriting(roading)rhodatato (from)the DATArTpter. BUB$I!,|ODE sektE a demand_ node DltA inrerfee. ln thie mde, the Dffi sgnal witf bo rerive as bng as there is atJ;pr* fi-fr; intsrnal FIFO to allow the transferto,csntinue.The DtlA eorrtroltii rospondsS assertingffieRand HEfrilEas bng as Dffi is mrtve. DBAtsus lrroDEis selecledwhenthe ggcggA ie mnneEtedto a DBA Bus.Thismodoalsocanbe callodDirectBufferAccess(DBA)mode.In this mode,the 33C93Aastsas a busmaster,andalldata'aee'sss(lnals reversotheirdirectbn:TheEmouput signalbecomestheDRQiitput, whbh enablesthe 33C93Ato driye![e bufferbus ontrol signals.Tho D7reRouputs[nal beomes theEG input,whichis assertd as a dlip selectforthe buffer.TheREandWE inputsbeome outputs*'hbh drive the read and write fundbns ol the RAM buffer.As long as the DRo signalis asserted,transferswill continuein a buretmannsr,untilthe !S$er is emplote or it decidestq pausethe transferby negdlngthe DRQ_glgna|;gne mo-retransfermayoccurafterthb transltion,ard thsn ths DACK,RE,ard WEsk;nalsare negated.

[:";,, :

i:]-.

i..{i.'':

DMA ftloDE is eeleciedwhen the slC93A is to be usod wilh a DMA mntrolferin eingle-hiletransfermods.tn thb mod€,Dffi b aEs€rtod and!!gt nggtd, ondthe DMAcomroflerrespondsby assertingDffiandwE or RE,lor eachdatabytetransferred,tofirom the fflcg3A

TIftiEOUTPERIODBEGISTER The TIMEOUTPERIODregisteris an B-bit register containing a presetvaluewhichdetermines thetimeout porbd for Selsctand Beselectcommards.This value maybe cafculatedas a furrctionof the inputcbcAfrequenoyard the desiredtimeoutperiod,as shownin the folbtvirg eguation: registervafue= 4E![ 80 Where: Tper * Thedesiredtimeoutper'rodin millisemrds; Ficlk= The inpt cbd< frequencyat the CLK pin in MHz(withno divisorapplied).

4'r*0

Theconstar$'80'scalesthe unitsof the equatbn,as is based on tho intemaltimeoutcycle time. Th€ ussr shouldroundlhe resultlng'registervalus'upto thenod intografvalusto ensurethatths usefs mininurm timeout reqlirementis met. Thetirneoutperbd specifiestprv longth€ 38C9$Awill wait for a rsspon$e(indlcatsdby asserlionsf $rs EW g]ggaflaftsr '$$t @$gun the selectionphaso (aesert sEL ard n€gateBSY)beforeterminatrng thocommard. The tirneoutfurption can be disabledby loadingthe TIMEOIT PERTOD registerwithzero. NOTE:Thefoltowing twefu regbters arcu*d exclusivel by

AmgltcgsA

the Tnnslate Addressandfur 'nmbination' &mmendrs. Tftefurr/rrrnof e*h registeris ddenninedby ths tyry of oomnandrbsuad.

TOT'ALSECf,OR8, HEG:IfITER/CDB r ST BYTE I'randats d#ressj Tho-TOTAL ,S.ECfoH$Jqffiar etpuhf bo $st to ffi |oref mrmbr of egctOe,perlra* prbr to issuirg a TranslateAffiruss mrnrnard.

Wstl-fe7$eh6t-61l&fieoejya;t,'.fw $il.st *:.w ntffi byta sl e ten or twatueqfio r lvd eng ft,thi*,, registar.

,, t0T]t BYTE sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssls6 Tfrb regristersfu.rH be badod HE*D $Uil8,FR RES$STEFIIB$B rransfinfs*dl''ss$ TtB HEADNuliBER,,rqls[er ffilr wilh tfts firs,tbrle of ttu couuAND DEscRtproR BLocK bebre bsuirg a sefect-ard-Transferooril- tains,tha r€ u[ing neio rnrr&er tglle$irq {rransss Address cornrnald, ff ,sutormsc eerrpaneEtbnfor manil. spare geatorsoR il, dlsfuie to bE peffuf,ff*d ry ffB wait-tor-sbcf-ardl*wvllve;ThaggcggAwillstorethe tfpn ths rurr,&r,d,spafiB perc$l*. , |rnryCg3A, first htto ol tte rec€ivodCDBin thilsregister. der ilurst be wrlttenirrtothis regicterhfore bstff$,sra TranslateAddresscommard. lt shouktbe rp-tedttrat when@rnFnsatbn b used,the rnaxinu,lm TOTALHEAI}SREGISTER/CDB nunber of 2NDBYTE TnnslateA&ress;This reglstertpltfs thetotalnunber cylffiers allqiledis 4096,andthe ma
AiltStG$ilA

+fr

TANGET'LUN REGISTER The TARGETLUN registeris used to tbkf both the LogicalUnltNumber(LUN)ard Targetstatusinfsnratbn duringvarious33CggAcomnnrdsard sesrences. Duringa select-ard-Transfer or Reselgct-and-Transf er commard,the mnlents of this register(alorq h'iththe SOURCElD register)are usedto generateand ctreck the IDENTfFYmessagostransfenedacrcssthe SCSI hrs. ln adclttion, the TARGETLUNregisteris usedto holdthe.Teqet Statusbyte receivedd.rringa SelectarSTransfgr@rnmand.

Com.Phaseblt 0 Corn.Phasebft I Com.FhassUt 2 Com.Phasebit 3 Corn.Phasetft 4 Com.Phasebfr5 Com.Phasetft 6 NotUs€d fiGtsrA

DuringWait-for-select-ard-Receive oomrnatds,this reglstermay hoH the imageof the ldentfi message recoivedfrornlhe lniliator.lf the TLV bit is zero,there wasrp ldentifymeesagsreceived.ff the TLVbit is one, thena valH ldentifymessagewas received.The DOK bit wifl then indbatewhetherof rpt the lnitiatorhas enableddismnnects.

SYNCHROHOUS TRANSFEN REGISTEF The SYNCHRONOUS TRANSFERregisteris usedto selectbetweensynchro'rous ard asyrrchrorpus transfers, and is also usedto deflnethe maxlmumtransfer rate.Forinlormatbnphasesotlpr thana "data"trander phase, or when the selected otfset is zero =OF0=0),asyghrorpus transerswill (OF3=OFZ=OFI occur.Valuesgreaterthan zsro definea syrnhronous DuringReselect-ard-Transfer commands, this register transfsrnr* ard the offset is detennind as shwn is usedto sst the LUNto h usedin tfe ldentifymes- below.Thieoffs€ildsterminestho effec[]veFfFOrfssh sagtssentto the lnitiatorafterSelectionphase.TheTLV - tor syrrchrcmusdata transfers,and ls typballydeterard DOKbitsare not used. mircd by negptiationwith the othar $CSf &vbe (as The TransferPeriod In advarrcsdmode,durirg Select-ard-Transfer com- definedin the SCSI staruCard). mards,this registeris usedto hardlereselecthnby an @rtrol blts selestthe minirnumlransterFrlod for both ard asynchrcnous SCSItransfersand,ll unexpe€tsdTarget.ln this case,this registerwill hoH synchronous the bgical unit nunber of the reselectingtarget.The AM-Busrnodeis used,thetransferperiodandthewirJth of the AEfiilE srobes for'fpst transfers.The perbd is TtV and DOKbitswill be zero. defired in tenns of the intemalcbck cycb tirne;the 7 0 frequercyof this cbc-kis determinedby the divigor selectedin the OWNlD register. TARGETLL.F.l bit 0 TARGETLUNbit 1 TARGETLUNbil 2 Not Used Not Used Not Ussd Disconnects OK TARGETLUNValid 1860SZA

PHASEREGISTER COMMAND TheCOMMAND PHASEregisteris usedduringconbinatbn cornmardsto indlcatewhbh phasesof these nr.llti.phase commardshavebeencorrpleted.Thus,il the mmmand.hasterminatedabnormally, the processor can readthis registerto daterminethe causeof the terminationand how to respordto it. This registeris alsousedto resurnscombinatbncommarrds by loading thb registerwitha valuethat indicatesthe nextdesired or sxpeqtedhls phase,and reissuingthe commard. Relerto the descriptionof the specificoommandsfor defiallsragardingthe va/pus commandphasesand resumevahres.

+42

Am33G1XlA

OFFSETbit O OFFSETbit 1 OFFSET bil 2 cFFSEf bil s TRANS. PEfi. b|t O TRAfifS.ffiR. bil 1 TFANS. PER. blt 2 Not Used fisc&t

BN

f{ams

0-.3

OFx

Desffp$on ThoOFFSETHts areusdlo solectthe &sired offsetamrdirry to tho fotforirq: 3

2

0 0 0 0 0 0 0 0

4-6

TPx

I

0

0 0 1 1 0 0 t I 0 0 1 1 0 0 t

0 I 0 t 0 1 0 t 0 1 o 1

o ,l

X

sehsredoftcat 0 (Asynchronulsdata phasetranefers) 1 2 3 4 5 6 7 I I 10 11 12 Undefined Undefined

TheTRANSFER PERIODilts areusedto seleclthedesiredtransferperiodaccordirqto the folbwirq table:

scsl 6

DBA Bus TransferPerlod

5

4

0

x

I cycles

1 1 0 0 1 t

0 1 0 1 0 l

2 3

i

4 5 6 7

I

t

(4 qlrcles) ( 1 ' ) ( 1 ' )

1 2 ' ) ( 3 ' )

t

( 4 " ) ( 4 r )

t

The 'cych' referrgdto fuve fs lfre perid of the intema!data transferM apltd. Thtsperitil is cahu|prted by thefoltowingforrnula: CYCLE.

TRANSFEN COUNTREGISTER The TRANSFERcouNT registeris a 24-bitregister containing:a preset value for the internal tranger counter.This presetvalue is baded into lhe intemal transfercounterwhen a send, Rgceiv6,oFTransfer commandis isued. This counteris used to define comrnardcompletbnby decremeilirq as each data byte is transfenedover the sc$l bus and gausinga "successlulcompletbn' interruptwhen the coulier reacheszero. fn combinatbnofiunards, this register lpecifies'thenunberof bytesto be transfenedduringa Dataphase.

(CSI REO/ACKSynchronousputre Wtdth and DBA Bus FEffiE putse Wdth)

dter the divieorchoganin DMISOR(fromOWNlD) (1mec) 2. INPUTCL@K FREOUENCY (MHz)

send,Receive, or Transfercommardwillbeconpleted whena singlebytehasbeentransferred. After the completionof any successfultransfer,the TRANSFER couNT registerwifi be zero.Thisincfudes commardsissuedin SingfeByteTranslernpde.

when a transleris interrupted by a halton efforcondition, a SCSI h.rs phase change,or an abort,the TRANSFER couNT registerwiilcontainthe numberof bytesNor sumessfullytransfenedto/fromthe scsl Pgr, inclulingclearingthe internatF|FOof any bfles leftin the FlFo (seeDATAregister). ThisFtFodtearirE The counterfurutioncan be disabledby badingthe proces$ maycausetheTRANSFER couNT registerto TRANSFERcouNT register with zeros prlor to differwith the user's DMA controllercount,because issuinga commardor byrsettingthe SINGLE-BYTE somebytesmayhavebeentrans{eredintothe FlFo, TRANSFER bit in the CoMMANDregisterconcunefi but not to the scsl bus; therefore,the TRANSFER withiseuingthoomrnard. Ifthecounteris disabled, theactualnumber the couNT shouldbeusedto determine of bfles transfenedtoffromthe SCSIbus.

AmlXffiftIA

4-fi1

,

I.,,

EG$jrxf{fifi$}t tu nggf$Tgn rogistor@nte#rsttp ermdod Ths OE$TIF,IATION,ID SCSIbns lD of the &vlce; which is to be sobded or reselectedwhen a Rseslsd or $elsd sonffi,Hrd ls

b'susd. This regieter'alsoooilaifts mrilrol bits tfnt efffffi ths opcrdbn of wrtEfin bn itomnufds.

7

SESTINATfi)NID UtO DESTINATONID blt T. DESTINATT}NID.Ht 2 Not Ussd Nd Used Nd Used DATAPHASEDHECTIDil SELECTCOMTJIAND OHAF{

8rr

De*dptlon

0*8

Dfx

D'E$TlNATlOlllD BiteDfO-Dflcortqinthe ermd€d SCSIbu lD of tfredev*mwhldr b tb be sabutedor resetsctsdw{ *,BE$ELECTor I SELrcT eonmard &sbsued.

DFD

DATAPHASEDIRECTION, whenadvancedfeaturesare Gnabbd(ss€ p.14),is usedto srelfy tha eryected diredion of the $csl data phase,whsn lt owlrs. ThF alfowstfp trlG93Ato veritythe direstiondurfngSefect-and-Trarsfer commandgbefore@innirq ths trensler.whsn this bit b zero,the exFcied dirsctbnls out (tothe Target).when this bit is qfie,the eryeeleddirectbnis in (fromlfie Target).An unexpectedirfonrutbn phaseenor wilfoccnrif tho'direcfibn doesrst'r$atsh,thesettingof thisbft.

scc

SELECTCOMMA|-|D GHAINis used only whsn the Reseld-arxf*Tranefsrmr,rffTtafd b issuedwlth,EDl-l. Thisblt selec{swhbh cornmandis chainedto whentfredatatranslerb ermfeted. Whnthis bitis zero,a Serd-$tatus-and-Commard4onptete cornrrardbegins executir€.Whenffrisbit b one,a Sen&Dis@nnect+vlessagp conmard boginsoxecutirq.

SOUNCEIO REGISTER ThssouRcE lD r,egrister b usedto reportths scsl fus lD of tm thathasselsdEdor rer It alsomrfrainsbitgthatenabteard controlre$ponse to selecfiion ard'resslection.

Blr

hfsmg

0-2

Slx

lD,B}bO*earevalidonryil the $lV bit is setto one.Theeebits lrdhats ttp $QSl SOU,RCE h.ls lD of the devlcsthatselectd or reselec[edthe 33G93A.

I

slv

VAttD is sotto oneafterths33C9SAis sebctedorreselectedtrtheother$C$t SOURGE'ID busdeviesassertd itssiln hrs lD bit (inaddltbnto the h.rslD blt'ofthe33C9SA)durirqthe phaee.ThisM is zeroil onlythe buslD bit c}tths 33C93Awas asserted. selectlreselec{

DSP

DISABLESELECTPARITY,whensel to ons,causesthe 33C93Ato igrnreths busparily whenresFordirq:tosele6{bnor reseledbn.Whenthis bit is zetro,anyielec{bn or resebCtionwitha parityerroris igrrcred.

ES

ENABLESELECTION, whenset to one,enabbethe 38C93Ato resporxilto a sstectionby ls bnored. anotherdevi:e on the SCSIhrs. Whenthlsbit is Esro,anyselecilion

'

5 ,"' '

:

,

J

.. 6

.,. '

,

t '"

,EH

Semrlpelon

i

ENABLERESELECTION, whensetto ons,enablesths83CggAto ruprxd to e reselacfiion by anotherdevhesn ths SCSIbus.Whenthis bit is saro,any reseledionis (7nored,

AnS$SgA

sclst sTATrfs'nE GISTER The $Q$l'rsfATus ragsor is a readrnS reglster whi0hi ated the.causeof the rpst recentINTRQ asssrtion.INTRQ is assertedwhenevera mrdition occurswit[gr tl.te6633993A that rsquiresinteruefiion by"tha fn$;,foJ'Gnrf,rfiple :

' Tns mC93A hasbeenreset; . The@mmardcompletedsuccessfulU; . Thebusphasechanged; o An qrmroccuned. OnceINTRQhas beenasserted,the conterilaof this registerwilf not changeuntil after the SCSISTATUS registerhas been reador urflifthe gACgSAhss been rgset. 0

bit0 sosl STATUS scsl $TATUS bil 1 scst stATus bit2 scsl sTATusbir3 scsf STATUS bir4 scst sTArus birs scsl,sTATusbn6 scst STATUS bft7

fi85&Or2A

Btr

Name

0-3

SSx

SCSI STATUSbits 0-3 are $atus qualiliercwlpse meaningdependsuponwhbh upper (F7l statusbit is set.

#7

SSx

SCSISTATUSbfis +-7 de{inetle type of internrptthat ocqrrred.The possiblecodesare definedin the folbuvingtable:

Descflptlon

qmo 0001 0010 0100

xxH xxn xxxx xxxx

1000

xxru(

The33C93Ais in a resolstats. A 33C93Acommandhascompteted successfutly. A ggcg3A mmrnandhas paussdor was abortedby an Abortmmmand. A 33C93Acommandhasbeenterminatedprematurely du.eto an enor or otherunexpected condition. An eventon the SCSIbus requiresservice.

Allother$tatuscode groupsarecurentlynotusedand are reservedfor ftrtureuse. ln the followirqtables,the '$TATE colurnn,,ffibates the cunentdate in ufibh the StatusCodecan omur. Also,ths'M0l fieH refersto the signatstfgt defirp a SCSIhrs inforrnatbntransferphase:MSG,C/D,end l/o. A bit st to one indbatesthatthe slgnafis assened on the SCSIh.rs.A zeroindbatesnegation.Whsnever one of lhese StatusCodesoccurs,the REQsignalis assertedon lhe scsl bus.Thetablsbelowsummarizes the meaningof tho MCIfield:

uc,fcoDE

Amen93A

000 001 010 011 1m 101 110 111

MEANING

DataOutphase DataIn phase Commandphase Statusphage UnspecifiedfnfoOut phase UnepecifbdInfoln phase MessageOut phase Mess4e In phase

&rl$

ftDl$triaFtbrugr sr$l||

'cdr

SEtr

W

mm

tlTr

0000

@01

oTt

WSelhrnflg gtGggA Hesst.The dwhm has b€enrerol, or a Resd commandhas €xscutsdsuec€rslulfy with no advaneedfedures enaUed.The nw $atc of the $rcs}A is dbconrnded. ggq0S4 t Tha&vhe hassuseaslulsomflsted a ReadcsrnmendwlBr dveirced featwe* ensled. The newstde ol the agcgsn ie dbenns.ted.

$rcmrtul Gompbtbnfnt rru$r s[|b

Stur 0001

@00

D

s001

0001

D

0001 0001

@10 001I

OT

0001

0100

OT

0&1 mol qoo! 000r

0101 0 11 0 0111 lMCl

DT DI I

$fficmrnftg A Resobcnco Ttrs nerucileteaf the SgCSg b connected FflId .*bd$rocegailulU, aBa Targd. . A Selecioommardcomplrtsd$rooesddry.Ths ms steteotm€ 33CggAis onneated as en Initiets. R$eryed'hrtsura uE{g. A Rslvq Ssnd, Resel€ct-ard-Trarder,Wait-for-Scld-and-Receiw, Send-Stetrpand-Gofirry49ornpl{te, or a Send'Dbsflnsct- tlessqe oommandcunphted srncascfully1Fffi' b rsaeserted). A' fuebg, S-md, Rg6ded-*rd-Trangfs, Wafr-hr€ehg-and{le€ivu, $eld-$tsttsand&mtnand-Complete, or a Sand-Disconnecil-Meeeqeommand com$etsd eumcedugy1ffi ie asseiled). A Transldo Addresscommardompletod wwcsfulfi. A Selecil-ard-Trenefer oommardonpleted umeefulfi. Rsseffodfor futun usc. A Transfer(non.MESSAGE IN Srase)oonrrnarder@ted strcceasfully. l{Cl ddines thr nsw ldormetbn tlpe (SCSIbuephase)bdng nguessd.

Prurrd or Abortrdhtrnupts &df

$ecruthnhE

0010 '

00m

I

0010 ,

0001

I D T T

ooro

ooto

0010 0010

0011 0100

0010 mto 0010

0101 0110 0t t 1

g0t0

tfiFl

A Tteneferfnfo (MESSAGE4HS*asel oommandhas paussdwith EeR assertsd.Thls allo*s lhe hoetto exsminethe messsgebeforercg$rq lt. A Save0ata-Poirfiermessagswasreceiveddurirq a'scfern-an&Transfer oomrnand.The ho$ ehouHsaveilg currentC*. hrffer pointer. A Selecror Reselectcommandwasabofied. A Receiveo-rSendmrnmandhasluttrd by an erroror $as abortedtffil. nd asswted). { lgeive * SonOcomrnqndhashrttsd bi an enoror by ae$ortbndl ffi or was#ned (mis aseertd). Reg3$vod for futurgu8e. : :: Reeerwdfor futureuse. Ths SilCggAhas been resslecteddurirlga Select-and-Tranefer (rvlfr E)l-O)by e Taqrst that does ld mddt the SC€l but lF haded into tha DESTINATilCI-| O regieteror the tol$irq Hrrffy mess{e did not rnddf the LUHbded hto the TARGETLLrNregister. AeK hasbeenlefl assertsdfolfou*rryttn Hentr'fimesEagp,ard the bus lD arrdLUNof ttre resel*lirq Targletdre evailde. In r$,n SOUACE D ard fARGef f-Unf.rugkrters. (AdvancedModeonry) A Traffifersmmand wasaborLd.ltQldsfkrg thr mn lnfrorrnatlon typs (SCgtSlr phare) beingreque*ed

t:

'

,: aaat

a

' : 1 a

:

.q

'

' , 1 . . 4

.'{ {s { .!i

5

{ '

i

l t 1 '11

i

,d

_:!i

j i {.i|fi

*tr${ISffiA

4

I

.{f

;-s-;il

Tcrmlnrtedlnterruptr $tetss

Cdi

Shte

0100 01m

0000 0wl

DTI I

0100

0010

D

0100

0011'

TI

0100

0t00

TI

0100 0100

0101 0 11 0

DT D

0100 0100

0111 1MC]

$cclffa trbanFtg An invalidcommandwas lssued. An unexp€cted dkrconnect iSCSfbusfree)by the Tuget eused I6mmgrd to terminate. The nsw stateof the SlCggA is dismnnociled. A tim@ut ocalred dwing a Seleetor Regelod ernmar-d. T state of the ggCSA b A pantyerrcrcauseda @mmandto termindo1Fffi-is nd assertod).Thetran$erdpection delermineswhetherfr b a SCSIor hostparnyerrof,. A panU enor carced a cqmmandto ternrinatefiTF ig $serted). The translerdlrg6tbn detennineswhetheril b a SCSIor hostparnvet$oF. The LogicalAddreesexcesdedthe diekboundaries. A Targetwhosescsl busdevicelD doesrpt matehthe bus lD set in the DESTINATIoNlD registerhas rosel€dedthe 33c93A duringe $ehcn-and-Transfer ommard (with lDl-O). This intorruptoocur8whenthe 3tlCg3Ab not in Advancedtfode. The new stateof the

ffiffi lffillfr il-:'* An

tmlh

-rran during asetecr.and ere rcommand.

unelqrec'ted inlormatbnphasewas requested.MCIdefinethe SCSfbus phasewhbh is reqmsod. This ig typicalfr causod by a phase change before the Transler Count has roachedzBroor ry an unexpec{ed phaeessquer}moelning durirq a Select-andTransfor comrngnd. $ervlcr Rrquhad fnterruptr

$tatus

Code

1000

0000

D

1000

0001

D

1000

0010

D

1000

0011

D

I 000 1000 1000 1000

0100 0101 0 11 0 0 11 1

T I

1m0

1i,rc|

Spcdflc iileanlng

T

The3IlCgSAhasbeenreselocled.The newaiateof the 33C93Ais ennected as an fnitlator. No ldentilymessagetransferhasyet rotrrred. The3$93Abaa boenr€8elsc't€d in AdvancadMode,TheSCSIbuslD of the Targetmaybe readfrornthe SOURCElD=r.eglster. The Hentifymessag€fromthe TargetmaybJreadf;; the'BAfA rtgisrter.Tfre AGR signal is teft asserted.me n€w state of tho ggCggAis connestedas an Iniliebr. Tho SSCSA,heebsonselected(trfi was not asssrted).The n6w etateof the 33Og3Ais onnestod as a Target. Ths SIC$BA has been sdecild (Hffi was asserted).The nEw $e19 of the ggCgAAis onneciled aBa Target. TheIm sgnat has-beenaseerted. A disconnecihasoacurred.The newstateof the 3ll0ggA b disconnecled. Reservedfor futureuse. The lfVeit'fsr'$elst-8ftd-Recslve commard has pausod beoatrcsthe'firsl Uts: of ths i*Try GDBie not a ltrpwn command mup. The OWH D reglrter mug Oe6eded nlth qts CqB hng$t, ?4d the commqndresumed.The CDBI rql*r msy bg examinedto determinethe SCSI€mmand groupfiom the opmde. Ths new stete of ths gggggA lg onneded as e Targg. {Advancodlriodeonly} The ffEQ signal,hasbeen assortedfoltowingconnscibn or when ths 3$IGggAis in ths lnitialorslate and no smmand i* exsautirtg,The informatbnphaeety1pn ehotrldbe erErnined.MCIdEfinethe information phae (SCSfbus phaoe)whiit is beidgroque$ed.

ffi8iffi}A

&{7

.tn

CO.m[tAf{DREGISTSR : The COMITANDregfisterie usedh hsue the 33Cg$A Thisregistershouldneverbs lodsd when @rnrnaFrds. the CIPor INTbits(in AUXILIARY STATUS)arosotto one,and a Levelll commandshouHnevorbe bded whenthe BSYbit is setto one.

coniurdbn wfrhong of these&nunsnds, the trandsr mlnter i dlssblsdars exacillyoR8ryte is to bo trensforred, regerdlessol the vah.rein th6 TRAI{SFER COUNT reglster, Ths prevbus mrsents ol ths TRAI{SFERCOUNTregisterare nd preserved.

The SINGLE€YTE TRANSFEH(StsT) bn in the Refarto the COMMANDSsecilbnfor a descri$bn of COMMANDregisteris only usqd dlrirq ir$.onnatbn th conmar{ts and their con€sporulirg omrnard transfer type commards. When thF ffi b sst in codss. 7

0

i

COITMAITD @DE Bt O cofrfiiaNDooDEBir1 csrM No coDEBir2

CODEBlt 3 COil,IMAND qOMMAI.IDCODEBiI4 C0ililillAf.lD@DE Blt 5 @Iffi'IAND COOEBlt 6 SIHCLE€YIE TRANSFER nc!.omA

DATAREGISTER The DATAregisteris usedto transferdatd'Wes ''b6tween the ho$t and the SCSI bus firrir€ the SCSI inforrnation transferphases(conrnard,data,status,or messagephase).lt nuy be aocessedby fte prosessor duringany type of informatbnphase(slnple Level'fl Businterface commarxls) or viathe DMA/DBA duringa scsl Data ln phase.orDaraQrt phase(sintrleard Levell! comrnards). cornbinatbn The DATAreglsteris actualtya portfor the hostinterface inlo the intemaltwelvebyreflFo of the 3Ec93A. The'FIFOi$ ussd for,all transfers{syrrchronous ard betweenthe SCSIbusandthe hostfus, asyrrchronous) for both DMA arut prgcogsoraccesstranefers.ff tlmp ABORT, 3SC93Ais to be haltedtoranyreason(thrgt4gh for exam$e),then data transforswith thb FIFOrrust offilm. ThHrT,ilitit contlnueuntilanrintemJpt be &ne m thatths'FlFOis returnedto a readystatsfor subseqgent transfsrs,andto fftrshinornirtgdatato the hosthts, ,

sefoctgd the tdlEard RE pinsbecone outtr*s, albwitg ths 33C93Ato *rtomaticalVtrander databetween fts DATArogisterard the extemalhrffer. In this trpde, buscorfrdcqnbe returrcdtothc enemalprocessoror anyotherdeviceby negatingthe DROpin.

AsqqtGonoi$onc HANSWARENESET Thsfstbtningresuils'omrrwhsnthe ggC93Als resetby tm ss$dtbn of t'frs,mT'signal:

. ThBAUXfIIARYSTATUSregisterls resetto zslo. ThofNTbil tandthe |NTRQpin)is setto onewhen tlp har$rare ressl cornpletes. . Th$O.|N lD r.eglster is resetto zero. . Advanosdirnods is disabbd. r The ES; EH, erd DSP bits in the SOURCElD reglslerare resstto zeto. . TlregCSrSTATITSregisteris resetto zero. . Ths isernsl FIFO, irrtemaltransfercourter (not TheDATAregisteris meesed by the procsssordlring a dataphasewhen'ttreCONTROLregisterDttA rrpde tho 'h6t accesshleregister),offsets,ard state selectbitsareall reset{-S},andwhenfte DBRblt inthe machinesaredeared. AUXILIARYSTATUSregisteris true. Ths processor The internalcbck dtuldercircuitis set to divkfeby writes (reads) tho DATA register by bading the two. registerwith ADDRESS a hexvalueof 19ard assertirq folbwing-hgst aocessble registers are NOT The pins. (m WE This 6 also occurs the ard a@ess affectedby the MR signal: duringnon-dataphases. . Regis{ers 01 hexthrough15 hex; WhentheCONTROLregisterDMArnde selectbitsare . lD (16hex)registerbt'ts0-3; SOURCE $etfor DMAmodeor BURSTmode,the DMAinterface . COMMAND is enabled.In this case,the.F$ registerb written register(18hex); (read)whenthe ffi andWE (HE)pinsare asserted Note: Ifre SCSISottfresetmayb tmplemented byusfrgfhe in responssto the assertionby the 33C93Aof theDm lo causea resefof thw83C934 SGSIbusresetsrtynal pin. (for example, with Ofr tie hosfpoyrer on resets$1nal the received SCSIbusresetfiST) s$nal).Thelwst Whenthe DBABusis selectedby the DMAmodeselec{ nay examine tto rryiisters flret are tlrlt afteded by ttn bits,ttre HCS pin furrctionsas an exlemalbufierchip MH s$nal to recrorv*rfrom fhe SCS/ rsset orndftbn.

e48

.AmSlG$ilA

SOFTWARERESET Thefolbwirg res.rltsoccw wfrenthe gScggAexecuteg the Resetmmrnard: . Th8 DBRbil intho AuxlLfARy STATU$registeris resstto zsro.The lNT btt (andINTRO$n) is setto ons wlrenthe Reset@mrnandls corplete. . All SCSIhls spnah areresetto the negatedstate. ' TheirfiemalFIFO,lnternaltrangfercounter(rpt the hosl accessible rqgister), offsets, and state . machines.are deared.

. The OWN lD registeris interpretedard the cbck divisor,tpst panty, ard advarrcedrfpde arg oonfigured. . Registers 01 hexthrough16 hexaro rcsetto zerc. The COMMANDregister(tB hex)is atsoresetto zero. . The SCSISTATU$registeris set as commarded by the EAFbit in the owN tD register.

coMMAt{DS GommandLlst Command code (HEX) 00 01 g2 03 04 05 06 07 08

s

OA OB

0c OD OE OF 10 11 12 13 14

r5 t6

r7 18 20

vand Command

States

Reset D,T,l Abon D,T,l AssertATN I NegatsACK I Disconnect T,l Reselecf D $elect-wlth-ATN D Select-without-ATN D Sel€ct.with-Imq and-Transfer D,l Select-without-ffiN and-Transfer D,l Reselect-and-Reeive-Data D,T Reseled-ard-Serd-Data D,T Wait-for-Sglgct-ard-Receive D,T $erd-Status-arilt-Cornmand-CompleteT,l S€rd-Disconnect-Message T SetlDl D,T,l RecoiveComrnand T ReceiveData T RecsiveMessaga&rt T RoceiveUnspecillsdInfoOut T Serd Status T SendData T Serd"Message In T $ard Un$pecilidInfoIn T' TranslateAddress D,T Transferlnfo I

33Cg.tA s!€te€,' D --Disr:;elnnectedT - hnnectedas a Tuget I - funneded a$ 6u, lnitietor

!--

il tl ll tf II lf ll tl I tl I il tl ll ll tl ll tl tl tl ll

cl

&mmand Levets: I - Level lcommand ll - Level ll command

AmSllSA I

Lovel

/*-{0

i "i l' ' ' i " : : ' i ' f i U l - l E I t F E g f E O F g S E L l g ' C nr O Therearetruobasft:typesof ffl093A mnrnards: Levef Whsn in nonnal (33CS3A}rno&, s rumhtilbn ndrsn drrlrq s Seld-ardi I andLevElll. LevslI oonmrardsmayb€ lssuedwhilea klle(ER-l) or urhendlscorslactod ,.(ard $s "T.8rggl, bus lS doss llot Lsvel ll mnrrnrd i$ in progres (irdi€ted by an Tran$ef mttm AUXtttARY$TATU$ot B$Y*1,G|PFO) ard, exffpt for nuEh the DE$iflNATIOI'IHl'rrufi$ter]caroosan lltsnsthe "Amil" afd "Re$gt"wmrnands,do rpt gensratsan date lnft$lfir$ aftar tfn rsgeMhn ,har$gfiake b inilsrtrr$Wq0lf$lr mrlpletion. Levelll mrrunard exe- s1rplete" In AdvancsdModa,tha SSCggAwill rcnlinue qltbn will ailrays result,in an lr$errupl.lf a Levsf ll to the MessageIn phassto fetchthe ldentifyrnessage. wifl comrnardis is$usdwhileamther Levelll comrnardis lf'the'S$ggA was HlE,the $CSl STATUSrugfister be setto 81 hex,andtho kkrltify msssagesrillbo in thg cxqgqtirg,urprodbtaple-resultsmayoecur. DATAregbter.lf the 33C93Awas exeantirqa SlectThere are two tlpas of l-evel ll cornmarffi. '$irplo' ard'Transfersmrflard, tho SCSfSTATUSregieterwill Levslll srffnands are associatedwith a slngleopor&. be setta 27 hox,andthe Hentffymessagpwiltbe h the tbn or phase (for exarn$e, sslsctionor ir*orrnation TARGETLUNreglster.ln eilhercass,tlB ffi,ltrcE lD, tmngfefl. 'Gonbinatbn' Lsvel ll snunarde combine registerwlll eontainthe $C$l bus fD of tlp reseMirq multl$s phases irtto a sirqls 33C93Aomruand to Target,anilth€ACKs$nalremainsaeeorted sottrattho minimizeir*erruptoverhsad.The lnitiatorcomHnation ldemifyrneesgp'fiEy bs reigctsd, 'expect'csfiain SC$l busphasesat certain ffirnrnands times&rirq a sequence.Theseexpec{edphasesare UNKNOWHSgSl COIffi'*ND GBOUPS bassdon cornrnonsequencsspeilormedby a Target Whena SCSIGonsnanC Descfiu Bbd( is lransfened on the SCSI h.rs; any dGviationcausesan intemrpt. on the SCSIbus,theomrnand lerqrthin bytesis dsterTarget csmbin ion commandscan bs chalned to- minedby the group€de, whichis tourd in Uts 7-6 ol gether to furllmr minirnize interrupt overfead by the first commardbyte,or o@e. Group0 (opoodes creatingbngorphasesequences. 00 to lF hex),gmup t (opoOe$g0 to 3F hex),ard group5 (o'pcodes A0 to BFhex)Gomrnarxte aredefined I@TE: When usit:ggg command draining, eare mustbe taken ff ()6.13f-1986)as six, ten, aftd by the SC$f st btoensum thd, all canmands in the ehain an inltialtwelve byte camrnnds, reepectively.All other conrEsd prior to issuing the ammad. mard grcupsap urdefinEdby th$ stardard.fn nsrmal ThE 3SC93Awl$ bs ln ono ol three lstates' during msds,,,tt$S3C9{}A'willassurnethet ttreesurdefined epr,f,t$rn: Dlwonnedsd, Connecitedas a Targol, or grgffi;,cro$ix by{ecsmmarulslfhgn executing$e&ctConnoe{ed as an lnltjator.Certaincornmardsarevalid aiuf.Trensteror Wait-for-$elact-an$Rocgive mmonlyin partkxrlarsilatesas irdbated in the COMMAFID mards. tn AdvarnedMode,the tollowirq eventswill UST,An attemSto iesuea Levelll mmrnardwhishb oGcrrf: irwalHlorthe preser$33C93Astatewillcau$san Tnva'' tnnsfar: rnmsnbsding the CDB lnto the lid conrnarrl" intemJpt.Level I commardsissled in $e CDB regietersprbr to issuirg tte mnunetd, the fpS irwallt stateswill be ilgrrcred. aFo'bffithe expeetEd mmmarnil'len$hlntothe OWtl Adllgncod,:Modg,,Fml u ros lD roglsturr, The 3S93A usss this valueto makesurs Tfia $3CS$Ahas'ssrs,rafr€rnrfeaturegirahded whbh tho ffirf'$# inumbarof byteoare thentran$0rrodln ths sdd nsil, frrnctbn$to th original3tl093 dosign.Some mmm$dlpha$e. of tfrcssfeaturescaussths 33CggAto be lrreompatible Whenreceivingthe CDB rd'-Recerva; wilh ths SgC93.Tho,ssfeatureshave been gnouped Wait-for-Sbtecf-a tqg€therurder the headlrq of 'AdvarrcedMode'fea- fromthe ilfiiator, the 33G93Awill c*redrthe tlrst CDB tures.Thesefeaturesaredisabledwhenthe 33G93Ais byteao Wrr as it is received.lf the grrouBls undefltled, rseetby ttreMF'signal(turdnvarereset).Theynnrstb€ an interyuptwill offirr so that ths hostcen examinethe ensbtsdby the host by bsuirq ths lReeet'mmmard tirst mrnr$Srdbytein the CDB 1$T regiser, ord then (EAF)bitsetin the bad th€ T0fel commard brsh inlo ths OWN lD withthe'EnableAdvarrced Features' OVtfNlD registsr.Ttrs hostcan determineil advaned register,l't6 SCSISTATUSregiser is sst to 87 hex, featureshave been enabled(therebyinplying that a ard the COMMANDPHASEregisteris eetto 31 h€X, s3Cg3Ab instalfedlby examiningthe SO$l STATUS whsnthis interruptoccurs. rrytiuteralterissuirgthe 'Regaltmrnmand. After the intgm.tpt,the 33c934 wilf onry accspt a Tha fealurss enabledby this bit are descrbed in the ResumeWait-for-SeIect-ard-Receivecommard,Abort, Disffinnect,or Rssgt comrnard.,All other mmmards folbvirg. tha 33C93A are invalH;duringthe intsrruptprg-cessirg, will contirueto transferthe first six b$es of the cornmard intoits intemalFfFO.

$$C$S Co

#t0.. ,,i,i,,:,lti

Types

81ffi$*

n*?A PHASE,Slf,Et:mam During a sebd-arxt-Transferooilunand in rprmal rnodo,lhe Dataphasedirectbnis determined solelyby . the Taqet; il thb directiondoesrK)tmatchthe oireaion expoc{eelby tha host,ths 33cg3A wiil not detectthis enor hlt expsctsthat the transferwill contirrue.In Advarrcsd Mode,the DPDbit in the DESTINATfON tD regf$Ierls compared$dthths stateof ths lro slgnalon ths sc$l bus. lf the expectedandactuatdirectbnse not match, an interuS will occur with ,unexpected phase'statusin the SSt STATUSregbter. Level I Cornrnards RESET(m HEX) The Reset@mmardperformsa similarfurrctionto the hardrarer€setcausodby assertir€the t[F'gn except that the ovvNllD registeris sanpted for infonnatbn cotrcerning th6 operaiingconfigurdtion of the ggcggl. The 33c93A is also initializedas describedin the - RESETcoNDlfloNs section.The Resetcornmand maybe executedin any33cggAstateandwilltorcethe 33c934intothe Dlsconnected state,abortirganyprevi. ouslyis$uedcommandin progress.uponconpletionof the Resetommard, an interruptis generatedthe scsl $TATUSwill be 00 hex or 01 hexl dsperdingon ttre ffntonts ol the OWNlD rugistor. ABORT(01HEX) The Abortfffilrnard is valu in the Disoonnected ard connsctsd-fls-B-Targst statos.The Abort@mmardhas dllfershtefiectsdeperdir€ on the state ard tho Fmmard that h affentry exscutirq,as dsscrhedbelow:

DrscoNHEcT(04 HEX) The Dismnnect@mnrandmay be used in eitherfiE Targetor tha fnitiatorconnectedsates. fn the Targret role,tho Dis@nnectcommardb lhe nonnalprocodrru lor dismnnectirgfromthe scsl busforknrirrythe infrcrmationtransferphase.In the lnitiatorroh, Disconnsd can be ussd to refeasothe bus loflowirq a tirrmut corditlon.The Disconnect commardcausssthe immediatereleaseof all bus slgnalsand, in Targetrpde, retumsthe SCSf bus to the Bus Free phase.tf the Disconnedcommandis issueddurirgan activeLevelll commard,lhs Levelll comrnandls lilrnsdietelylenninatedard the 33c93Atransitbnsto the Dimnnected state. , t .

ASSERTATN(02HEX) The AssertATN mmrnandis onty valkJwhen Connectedas an Initiator.lt is normallyusedto ahw the Initiatorto irform a Targetthat it hasa rnsssagepsrda ing (TheTargef_isexpectedto respondby performing MessageQrt Phase). ATNis automatically negated: . Beforethe last bfte of a Transferlnfo conunard issuedin responseto the MessageOutphase; ' when the ldentilymessageout is transfenedto tfre Targetduringa Sebc{-ard-Transfer command; . Whena SCSIBusFreephaseoccurs. The sefect-with-ATNand $etect-with-ATN-ardTrans{er@mmandswi$ causetho33cg3Ato automatically assgrtfffi prre'^r to the releaseof m providirq the busarbitratbnis won.

Diesonnectedstats: In the Dlsmnnect€dstate, the Abort commard may be used to halt an attenpted NEGATEACK (03HEX) sebct, select-ard-Transfer" Reselgct,or [email protected] the Abort commandis issued TheNegateACKcommardcausesAEKtobe negated. folbwing a select or Reselectcommandard the It maybe usedin the fol|owingsltuations: . after auccessfufmmpletion of a Messag€.ln A|T!33C93Alus won arbitration,the Am33cg3A TransferInlocommands; rsleasesthe scsl h.rs by removingthe Bus lD bits . afterthe33C93Ahasdetecteda parityefforon arry $ilr ffi n assertsdand-checkirqrir llgg",sd ETi s{pal. lt afterat leas 200ps,thereis noBEVresponse, receivedSCS|infonnatbnard the HALTon SCdt theAfig3c93Aguosloa BusFreecondition andgenerPARITYERROR(HSp)bil is ser; atesa pausedlabortedinterrupt.lf thereis a response . after unexpoctedreselectionin advarrcedmode; "successfur withinthistimeperiod,thena compietion' ard intemls will resultinstead r &fter a ggyg-rlgltfointer message is recsivd, Nols that th8 Am33cg3* wiHneglectAbon cornrnafd &rring8 $sfo{t.and-transfsr comrnard. unlsssthe comrnardis mnpleted. Afterthe cornpletbn partty Host efforsdo not affec[the lffi'slgnar. Forarl of a oorffrland,tho Am33Gg3Awit| s-ceeptan Ahort otherlnitiatortransfers,m negationis auiomatb. $rnrnard and:will.go to thg Bus Free phaso ard gsneratea {Pause/Aborted lril€rrupl'.

Amfim0(}A

&5f

ln thg ca$s of a lile,wAgo-lnt lrssr lr sryss Frsybs r#cilsd ard the tnitidor msy irdicateits mtafit to,,sord efthar a IT|ESSASEnAIEC-r or I "IIESSAGEPARITYERROR'Messqe by beuirg the prbr to lsurir,qthe Nsg#e A* Aswrl rtThf,ogrfilTtitrtd ceqmsrs. ll tha inmrrfrrgme$sagpis b,bs ascess4 onlythe NegnteAd( conrmardsfprfiil bs hsnsd. Drrfrrgrpn-Messag€-lntrensters,il the TnansferconF manl is tsnninatedby a parfiy srTotr, the AsssrtATN Go-rnrm$oan'qaFrbs'bsrr d pbr to NogateACK,this mq irdbetirq tho lrsthtofs trfent to send 8n "lNfflATORDETECTED ERROR"Mess€s. sET rrlr (0F HEX) Tha $st lDl mrrrnam- is ueed h thq |nitistor tole to s.FBort overlappedSCSI opsrations.ff a SCSI mmr$gr-,S. is exoartfE,vh a $elsst-ard'Tranefersrnrnard, thn theSst fDlcomrnardmayh usedtosttho lDl ffi in the CONTROLregister,whicfrlhen causesan irilernfr to mrr upona Targotdisconnedion.This ability a$owstf tBl bft to b left roeetwfpn the first $CSf opgratbnlg $arted,whicfrmay re*a0e,tfiGmrr,tgr,of !qC93A mafnlss, Id slso ahw$ a eeoondopo€ttln to be stanedwhen meded wilhoutwaltirg for tha lirst ryeratbn to be onpleted.

Slrnpile,Lsrrl'$ Ggrnmailds

sdbatss $rt tf$ ssld-$ilF*TT{ mmmf: aor@ed alwssfuHy.

em

.

lf tho 3llC93ASes rpt win tte arUtratbnor tture is m rossorl$sfmrn tf-ffoTaryel a4 the titlle-outfeature ie disablsd, ths Sstsst:lffih-ATN commard caa bs abortd with an Abort mmmand. l/llhen tho Abofi oommarrilis guccassfully exealtedun&r thesecilcunr starrces,lhs StlCgSAia dlsconneciled fromttp busand a lausad/abortsf intemrg is gernrated. (W HEX} $E|.ECT;WITHOUT.ATil The Select-wnhotil-ATN comrnandb ffintlcal,to Sp Sslest-wfrh-ATN conmard excepttfrat Fffi h rpt set &ring the SslectbnPhase. (05 HEX) RESETEGT The Reselsct cqmnf,rd is irtontirpf to ths $efgdwithfi-ATN consnard exceg $lat the UO sfinal is essertsdupon mm$atbn of ths Ahitration Phaso. Succes$ul conpletiln of the Reeelect conunard resultsin the 3gC93AbeingConnectedaea Targot. RECEUE(1S13HEX) Thgrs ar€ f€ur ,Rscsfuesrxnald$ whiSt,,firgdi$inguiehodfrornef,shotfieroffy by th etatsof ttreg SCSI il*srfm g$nalsandths typs of datathat b transteFr€d. Thess 6-ornmands,consisting of.,.the Re-csiva QrynnnA, :RoceiveDsta,Rgqive,Memqe Out,aruil R UnopeclfisdlnfoO,4oonunandoare vafil on$ in,,tho,,Gfrilracted.gg-a-Targgt Gtale.Ttlg $ps of ths RSffiVsoornrnandsolestsddstgrrnirpsthe stqt€ol the t6, C/D, and M-S ouputs during ths comrnard ffifdirry lo the fosowirqcharl(lco$ssrld):

sELECT.Wfrlt-ATil (06 HER $sbct',$ftf,l'ATNis val$ on|yin ths Offinlwed stde stld r$en ,htuod'ryllt causs the 33Cg3At'o eehd a Terget.&fErs lssrrl!€,this@rnmand,th $CS,l&ls lO of tfts Target daviso uhouH bo Hrlilsn ir$o,,'lhs DESTiNATIS| lD ragnuilBr; Utlhenttu $etsct-wHtrATN sonur*ud le lssrJsqthe 83Cg8Ahryins buoart$tratbn. lf .:tho,, 39CggAF oebtf;od,or"''rguqlecil6d by another Rreh$ sornmand Tm &vbs durirrythe arbitratbn,the $elecf,-with-ATN @,n1., Rqsivs Command ' mand k abofted ard a lservbe rcryired ifiorrufl ': ' :.; Reaeive0da r (Sxfrux)b ggnorals. $lWtH tlB gACg$Aw,in,rtf,p, arWr$ion,,6Et ard Itrfr ars scso6gq[, ltg Targrst, @rlnitiato{ guef08 proSa€d on ths $CSf {tats hl$, n{S,han ffi U d*asooded.*t thb tlne, a tFfioor$sqnrm wfioee lsrrytfl b &torrffned by the vatueln the ilEOUT:trRtOOrsgtstsr hg$ns. ff B$Y is t$t asssftsd,b,yth8 Taryotbsfsre a ffinc{ut oodhtrs,,tttsffi$9A Wifis its sletilisn abort $qr€rs {ae,desorhrf in the tbnl, ard,ff thers is rF Tf,rgct,rc$poru$e tha $sfectwilh-ATNommand is termlnstedand a tenninatef irtsmrs b generated.tf ttu Targetrespordsbeforethe tirruot$psrbd hasdqpsd or beforetho sElactbnatoil sqt€nce ie mnql|ete, tfp 33C93Anegatcsths ffi *[nal, F$tlng the 33Cg3A in e Coruucted-?$-dhIn$tiatoratate. A "Sr.lccesgfulmnpletion" ir*erruS

|.t8f.

Rssive MessageOr$ RsceiveUnspee$f,i:lnfoOut

OFG€IDE fFC , GrO UO 10 tI 12 13

0 0 1 1

1 0 1 0

0 0 0 0

The Receivemmnur&, are lnfofin$lqn trangfefiing mmmards arxl are fiFraforedeperdert on the SBTbit ln tfn COIIMANDregbterfor detennlnatbnd a $rccessfulconpfetbn.ln a*fitbn to a tsrminatbncausod by reset(viaeilhsr a Reset@mrnandbeirq issnledor pin],a fiwive mmn.tlm mns-' assertlorlolf,rthe,tfrFl tbrf ori filtldbnwlll ffi$ uressrany of thgggwld.tbrx: tf l T:,fu,ir*omal translsr muntgr is dieabbd (SBT*{,or tfulTHAN$FEfrGOUNTregiuterb loadd with zero) ard a slrgle $fie has been read frcm the DATA register;{2) The munter has decrementd to rero ,(wfth$Ef=91 irdicatingthat the spsgffledrrun$ar of bytashave beentransfened;(3) A paritytinor has

*ffilffisr*r i

;r ;lx ::':-rd

been r!6sn cflffiteo dstffited on on ons ons d ffie the rcceivd rccoivd data (ard data bytes bytes(ard HSP-I); (4) The Fffi prn b asserted (and HA=rli tSt

Ths Ahfi cornrnf,rxlis issued; or (6) A Disconnwt cofiunandis iasugd. whenthe freceivgrcmmard iscompletedas a resuftol receivingthe conect rumber of bytes, a "successfuf compfetbn'intemrptwitl be gen€rated.lf a parityenor has causedterminatbn,a tenninded" irilemrptwill iretead h generatd. In this cass, ths THA}-t'Sfdn couNT registerwiffmntainthe numberof bytesyet to be transferred.Alter any conpletionor terminationof the [email protected] a sub€e. qrent Dismnnectcommandor reset,the ggcggAis in the Connected-as-a-Target state. As data tran$er cornlmrds, the Receivecommands are d frdent on the DMA rnode s€fect bits in the CONTROLreg*sterfor ths DATA reEisteraccessirq mod8.Thesebltsdotenninewtetherthe DATArogisilor rcceeseswill be hardledby the processoror througha DMA/$BAirfisrfaco.wh$n ttp proc€ssorts reqrirsdb raadthe 0ATAregister(i.o.DMAnFds selsctbfrs-0),it rarsl rnpnltor the DBR status bit (in AUXlLlAiiy STATUS}. to daterminswhen'a byte b avaifablsfor readirg. Durif€ Receivecomrnsfids,thb statusbit ryifl bs rse€twhena byte'isreadfromffiBDATArogisterard setwhena byteis badedintothe DATAregsterviathe SCSI interlace.DBfl is also reeotwhsn a REceive @mrnandis issued.

The Ssrd comrnandsare aho iffio

.fi

mmrnar,rds anqas sugF*rs alsodoBefssnt

'ffi

SBTbit in ttm COIdMANDrqister frir enunar$. pletbn.In additbnto thatcausd by reeet(viaeit$wr.e Resetcorunard beirq issuedor assofibn of the Mn' pin), a Serut@mmardmnpletbn or terminationwilll @ur urder any of these @rsitbns: (t) The lrfiemsl transfers$ntar b disal*od($8T,*t ortho TRANSFER COUf{Tr{ilsbr b bffi wfih zero},at$ e sinds,hytg hasboenred fromths DATAr,ogistec {e} Tfrc@ur$sr has @rsrnersed to zero (wth Ser.'ol iii#stirE filat ths wifbd nurrsar ol Spteshe\riobssn t{urfisrsned; (3) A parityeror hashssn,detgqtod onotn oi,,tf$&ta Hfieefromttu host(andHHP*l); (4) lf ffi pin:is asso-rled t*rd HA*l); t5) TIE Abonmmrnrrd b.bsugd; 0{r(6}A Disconnectconsnsrdis fq$od. Th ffiSgA rumains Conn*tg$as-a-Target fotbw@ the ,SM cornrnardoorrpbtftrrfiennlnatHrnunleesthe Dhoonr€atco-rrunardor regetwaeusedto brc€ a terminfiilon.

Duringa Serd oornmard,DATAregbter aqstsirrg is contrulbd by tho DMA npde selest bits in th6 CONTROLregister.Whenthesebits are set to ttreap proprktenpdo, batlirq of the DATAregisteris ammplishedby a DktA controllsror throughthe Am-Bus ifierfrce. lt the DMA nrgdembet bits are.zero,lhe processorrnrst poll tho AUXfLIARYSTATUSregister ard canwriteto the DATAregisteronly whenthe DATA -Serd BUFFERREADYblt is sst (DBR=1). conrnands eaUsgtho SBRbil to be res€ileverytimeths pnoees&r All informatbntransfersinrrolvirgoherthan dffi infor- bads a bge intothe DATAregFterandset$hsn a grte is transtsnedfrom the DATArggisteronto ths SCS| mgtion,ar$ a$yncfiromug., lfueveF, lf 'thg inlon tbn data bu,s.The DBRbit wllf afsob set upon iss$rg a plrese hvolws data the SYNCHROf{OUS , THANSFEH registerwillbe waluated.ln thiscase,any Serd comrnand. selectedoffsetotherthan zoro resultsin synchrorpul As in the cass of Receh€ oornmard$,symhroturrs tranehm.Ths minimumTrang{srPsrfodlor botlrtypes transfers will occur only when data tranders ars lnol lransfercis detenninedby the Fansterpgrbd in vofuedard an oflsetotherthanzerois selected. hlts : :"'. : thissameregister l

SEHD(14-17HEX) As in the csseof tho Rmive corrunands, therearahr Sent mmmarde wtrlchsra-$Btingutshed onty by $re siateof theiF, CrD,andffi pirrs-and the rypl of dsa tf,Htis transtgned.Thetour arld,comfFard$,, abs,,voftl in the Conrpcte*as-a silateonly,are the Sgrud $tatus,,Send Dstg,,Eetd Mgggngg,[$,, grd Ser,S Unspecifbdlnfo,ln mmrngrss. Tfie SC$t pln statffi. d.lringthe $erd ffimmards,ere deternilinsdby SrspsF. tirularcorntnandss follows{aEEefied*l,}: .,. $and Conmal..rdTypl Scnd Status Sond Dala Send Meseqe In Sgnd Unspecified Into ln

opcoDE lmG, GitD ss 14

0

16

, 0 1 1

r5 r7

i

t

mANSFERfNFO(20HEXI The Transferfnfo oomrnrd b vaffi onry when CoBrpctod as an,lnitistorard ie usedto serd end receiw dfita,@mmarril,status,,arNdrngosaggirsorma$on. The firs{ Rm asseilbn tollonrirtrX connectbnas an lnitiatorresultsin a lservbe reqnired"inlernrs. The processorshouldexarninetha SCSISTATUSregister to delerminethe typgarfr dlrsdion of ir$ormatbntrans, fer reqrestedby tho Target,ard then iszuea Transfer Info commard in re$ponso.While an Initiator,ths 3rc93A wilf also generatean interrupteach time the Target devbe reguestsa nsw type of inlormatbn tnari$er$aso.

0 1 0

AmSASSA

+$s

*r AB.in.tftssas of the $erd s t Rgwht,:etrrnltrat!&, ufien coilFlstklrr of ths Transfer lrfo wmrnand &. pords uponthe lnternaltransfer countsr,the processor shouldload th€ TRANSFERCOUNTreglsterpbr to isruirg,thisffinmand. TheDMA'rDd-e ssf€ctbitsInthe regfetur,tfrooffsstandtrshsferperiodbttstn GONTH,OL rho sYNcHnbNous TRANSFERregist'er,ard the SBT bil in the COMMAT{Dregluteraie ueed drrirq Transterlrto emmar$ iust as they are durlrq the $dffi. srd,:Rscelvsornfnfilde. Honever,for proc{ssor ffis s of the DATAre$$gr durirg Transferfrrfosrnmande(whenthe DMArnodsseleclbr'tsarezsroor the bus:,phrrcs b otfrerthan Dataphase),hhavbr of the DATABUFFERREADY(DBR)statusbit is dEtennirpd llthe directbnof informatbntransferas defirrcdby the l/O pin Whenthetransferis fromlnfrialortoTargiet; tfre DBRbit is rsset by writingto the DATAregistorand is setwhenthb byteb transfarredfmm the DATAregi$sr 'the oFrto",tfte'$C$l data"hls. Wherf transter'i$ffufi Taqet to lnitiator,DBR is set when a byte i$ ecefu€d overthe SCSIdatabus ard transferredir*o the DATA registerandis resetby readingthe DATAregistar.DBR is aM re$€twhenevera TmnsJerk$g.cotnmardie issued.

nsgatbn of-the ffi signal (i.e,lho Tgpst srd&Ifi dismnnocts)sr I transltbnInthe l/O,Ci/D,andor M8G pinsdurirq a Transfermmrnardwil abo temFratethe oomrnandanCgerrcratea terminated interug. lf e pq$y errorls dstdod on e bytabut parifi €nor conunard terminatbn b disabbcl (HSP-O sr HHP"'O,8s approprfate), the 3tfC93AwiHdill sst the PARTWERRORs{atJsbil in the AUXILIAHYSTATUS reglstarhlt will not terminatathe mnrnard as a resu[ ol this error. ' . . : TRANSLATEADDRESS{rS HEX} The TranslateAddressComrnardperfoms a logisah adtreesto physbal-dhoss translatbn.CertainSCSI commatdairwska a Q[cal sdrees whhh maybe W to gAbn$in bnsth. Vllhsn4'st''ilrnard,isdst€c*ed's,hblr reqlires d#,€$ translatbn,tho'rcc€gsorffil relO$ the lqgieal .address into ths gSCgSA LOGICAI ADDRESSro$ster snd then lsara the T,rEnElate Addressmrnrnar$ to havetfu gg0gqAdo the"mmrersion; Upon receiviqga lsuccs sftrl oorrpplbn' intorrupt,lhs proces$ofcan red tte CYL${DERNI9MBER, HEADNUMBER;,a;dSECTORNUMBERruffitBrc to df,tractthe Fghal e*lress. Tho,ffik pqramot€rs@n* tsir"rWin the TOTALSECTORS,,TOT:AL HEADS,snd TOTALCYLINDERS rqisters rrustalsobe velidbefore is€rllr€a TrandatsAddreseoorurrard

Therearo severalcausesol a Translerlrfo corrnand in adfrtbn to a reset.Justm for mrnpletbn/tennination a $erd or Receiw eornmand,tfie Transferlnfo commandcan be terminaledby issuinga subsqquentDismnnect or Abortcomrnard.The Abott comrnardwill tf a$tomaticconperusationfor epars sectorsls to b 'ppffifnlqdbytf€ ArnS$€ggA,,thntfle runrbsrof spare causea lausecUaborted" irterrud to be genaratedaftsr executbn (leavlr6 th€ 33c93A in' a aofmoded sdQ*p,p6r c$irder and total rrumberof gec*oru"por 'als,bs bM; respedivsly,lnto the sta{e};whilethe Disconnect:o0mmarid causesanlrnrne- cyffi,fiu$t HEAD;hlul, B€R ar$ OYLIIIOE R Ntlt{BER roflstere.,-A diatedismnnectard &es notgeneratean intemlpt. tert$-ffiEd1 interrupt.wifl offur il arrydivisbnoperdion A Transferlnfooommandwill eitherconplatoor paues per,f@during this commardresu$sin an overflow. :a' wfmnthe'specffiedmrmbsrof bytes(oithOra sirqle byte of rnrfiiple bylas as defined by thB SINGLE-BYTE Conblnaflon Levefll Commands TfiA}{SFERbit in tns COMMAI.IDrcgbter} haebeen (OSANDOgHEX} sgrltot recgi\ted.Tho33C93A,gsnerat€s e *Bucceesul SELECTTfiND.TRANSFER The Solsc.t-and-Transf mmmands er $tsatryrsdrs-thg gpttpr csrylstion" lRterrugonty afier,rereivlrg HEei processu froil| 16s Target durlng ren-Msssrye-ln tnfonrntbn host sr bcalgSCSilA's lrfrsnryt-fuandlirgburden by tilternafrniuoproms$orto nnnphasesh.rt gerrerstese ?zused/abortd interng tor enstirlg,the pffiml, resufiirEln as fsuvee agp'ths b.w-lsvsl,,$C$f Uersage-lnphaseswithoutwaitirg for an additbnal one irtsfr,Upt', S0$I,sperEtbil;' $OlSdArd-Trarnsfer Ff REO(NotethatwhenthecorpletedTransferlnfommard typi. mandwas a Message"lntransferphass,ttn ACKpln commandeare usedwheRin an Initiatorrob, phases:(1) teast folhrirg calty corwbt the SCSI of at witlbe leftassertedbythetrl0g3A in the lastHEQ-ACK (2' Ssndfqil d s srncyc{eof the command,ard the prace$soris requiredto Slwtbn of a Targ€ildsvice; issuea NegateACK or an AssertATN folbwed by a mar$; r{31 freceptiun ol $Blrrr! lrfrormstbn; ard t4} GOMPLETEMossqo. Negate ACK command to accept or reiect the Rece$bm,of a CCFvIftfAND Th€ss',ffir.1tmgrd$ optionallyonsist of' a'DataTrengls message). phaseard additbnalMessageTranSerphasas. lf a pariiyeffor is dete.Asdon a databyters.olvsd frcm ths SC$l bus (srd H$P-l) or on a data $te hrte TheSSCSAwilfupdatethe COMMANDPHASErqi$commandexecules. recetued,frorn the host(andHHP*I),thenths SSG9SA ter a8 thg Sglgd-aruC-Transfer mnpletbn or terminationof the corunard, the wllllerrriiqa!-e for S€$l parilyarrors, Uponprocesscr the commardar'dd, can read lhis regiser to dotennlne will leaveEffi assertsd(to alsohattthe Tirget). tn this hal where $B SC$l operati,on $opped. caso a terminated"intemJ$ is generated.Finally,a

+a[

im$f,@$A

Th$' ftvo,$glectand-Trensfercolrunardsditfer from effih otheronly by wherheror tu fire ffi-O;is ilffird during$p Solectionphase.The abiiltyto ass€rt lrlf rturtru $efeetbn silrffirts ths ssl Meseagn Protoml whictrcatfsfor an |DENTTFY Messagecjlrt phtee folkxringtho SsMiOn. tJVtton exeafiingaSelec{ wATN-anc-Transercommands,the gtlcggA expects ths Tafsrstto r€gus$ta Meesagsafi phaseinrneoialely folbwirry eebdion, whersasfor a select wo ATt{-ard-Trarufer@mrnar$,il expeclsthe Targetto directly enter command phaee. The selectancTrqnsfer @mmands, fiproover, suport Group 0 (6-brteCD8), GroupI (t0-byreCDB),and Group5 (l2-bfle CDB)SCSIcommarxfs.

FHtqlregietor udttffiitain, hsx gS wt*cn d byfts of the cDB tuva beentransfoffi::

Aftertheconrnandphass,theelcg3Asxpectgeittpre DataIn phase,DataOutphase,Stalusphase,or M€Bsageln phase.lf the Targptis re$lestlnga Mms*gu tn -The phase, a perdirg dlmnneGbn is eezuilrgd, SscggA tfpr€fors expods b rsogFe eilhar a,sry* Dd*Pointer fiEgsagp {hex 0e} or a Diffir,nffit mossage{hex04}, ff.gfthr nussage ls h6ns$, or il f, differersmsss4p is rmelvd;,a *ts|mlnatsd Frtemry will be sneratBd to abrt tfn processorof that f8d ard to allor the messsgFto be readfrcmtha DATAFag,issr. A "tenninated"intemrplwill arso be generated lf the -the Target dismnnects before sendirq Dism*ntri whsn a Selmt-erd-Transfer',comrnand is issued,the message.when a conectsave-Dati-pointermessagp 33c98Aabitratdsfor the busandsebctsa Targntjust is receivsd,a pausedlabortedInterruptis generatgd ag.durlru a selgct commard.lf tlp rar,gretdoes not ard the setect-and-Transfer commardterminatedto -respord before a tirrpout occufs,.the seld-anclafturtrtherprocessorto save the scsl rl-atapoirrt*r. Transfercommandhailsard a tenninated'irrtemrptis However,if a Disconnectmessageis received,tle generated.Failureto mnpbte ths sef86{ionphaseis coiTMANDPHASEregisterwiil be updatgd hsr to 4l alseirdlcatedby the factthat ttle cs{*tAND pHAsE anqcommar$exgcrlttonmntinues, reglstsr@rsslne gLrcess{ul, : all aBro8.lf fi,rgsbction is rp intemrptls gen€ratod,h* tho contMAND pHAsE when the ac{ualralgetdisconnectiondoesoffir, ths OOMMAND PHASEregisteris updatedto hex4if ard ff registerwiil be eetto a hex 10. the lDl bit b ast,tho *rnggcgsAterminates ths $bdan gstf internrpt. Ittr.r conpletirg the setoctionphase,_l& g{tcgi}A 3$-Transrepoomrl#d by gonerattng '.r€ssl, begins'aninformatiori transferFhase.lf ffi trasbeen However,fi ths lDf bit is thgn lfrsteadthe assorted(i.e.a solect wATN-and-Transfer commarrd Arn33c93Asitsin an ldleBtets,wailirgfor theTargetto wasissued),the3ilcggAexpectstheTargetto respord reconnect.lt a differentTargetdevile nesete{ili thg witha Messa€pOutphase.lf thefirstinformation phase 33c93A, a terminated' intemrfl is generated.Hourresiost ls other than a Messageo,fi regro , the ever, it the originalTargetReselects-the BtlCgSAm 33c934 will terminatethe commandard generatea interruptis generatedard th8 CoMMANDpHAsE terminatsd'internpt. However,whentho Targstdse€ registeris setto hex 44. requesta Messagebut phase,theggcgoAwill-respord by automatically serdirp an IDENTIFYlieseage.'Thls Fotbwirgthe originatrarget Reselsctbn,the gilcEgA sirqle byte messagpis of tho binaryform: 1o00ttt, expcts a MassageIn phasertfiicfi eturu consbt ot wh€ro r*'l if ths ENABLERESELECTTON_ Thb sirgrF b,ilh fhe thaTarystscrdingan tDENTtFyMeesage. $ouncE lD registoris eguatto 1, andttt isthoermdod byta iTrsssqF sfioutrlbo of fu blnery,ioum:.t000Qe Ta,rgetLoGlcAL uNtr NUMBER@ntainedin the wherettt ls the TargetLtrN. tr ths dsta roceivedby ile TARGETtuN register.once thE tDENfiF/ Messago 3ltlc93Ais dlfferentor ttreTargetLUN,spdtsd h $ris bytedoesnotmatchthecontertsof the TARGETLUN ha$ been sent, the 33cg3A wiil set tho coMuruto register,a 1erminatsd"intgnuptls genetded ard ule' PHASEregisterto hexA0. Messagebyte may be examinedUi the prooessor.A Folbwjq.the Messrueo.rt phase(or setectionphase mnect'$gNTIFY ltfsssagpIn phase resultein the whenATNw&snot as$rted during$electbn),a corn- COMMAND PHASEregisterbeingupdatd to hsx 45. mard phsss is ocpectedby the OgCggA.Again,ard througflqrt ttrc entire Select-and-Transfer mmmard After the IOENTIFYMessagels recaivedfirorn,,ttp afterthe commard out phase exscutbfi, if lhe Targetreqresilsan unexp€dedirilor- Targelor imrnediatety (whenthoreis rp dlsenn6ctbn),a,Da|gtn phase,Dete mationsrase type, the 33cg3A termi:nates the conr- qn phase, or $aUs phase shou$, osur,. lf the mand ard generatesa "tsrmlnated"intemrpt.lf the comrnard phase is requestedin this situation,the TRAf{SFERcouNT rwbtor cofitakurany rpn-r€K} 33C9SAwill eilmct the $csl commandfromthe inter- value,then the 33cg3A win,expac*a Data Transfer phaso. lf AdvancedFeaturesar6 enslsd, thsn the nal colriMAND DEScRtPToRBLocK regstersard sendthd6-, l0-, or l2-by{esof commardinformation as DPD bit will be examinedto verify the cons{t data determinedby its evaluationof the scsf cornrnard dtrection.lf the datadirec{bnis irrconecl,th€n'a"temiInthisphase,theggcggA code in the CDB1regisrer.The COMMANDPHASE nated"ifiemrptis generated. registeris setto hex30 beforethefirstcommandbyteis will usethe TRA^ISFER couNT registerto determine sentandlhenincrements witheachbytetransferred, so the numberof bytesto be transfeffed,ard all host-slde that for a 12-byteCDB commandthe COMMAND DATAregisteraccesseswill be acconprishedvia tfre

Aa€Sgg*

It"$S

rrptW,ssbdd by ttls B[fA'nFdg sem bJ|sln the Wten $F htemalcqrnbr reetpg regrister. SOS{TROL refoi tho Deta Transferphase is mmplete and the PHASEregisteris set to hex 48. OO[dtrtAND

Colrrmd. Ffter

Nots thet arry nlrbsr d disconnedbrVreconnectbn 6yes may o@Jr durirg ttts Dda Traruslerphase so brrg s*they art @rnplished acmrdirgto thedefind PHASEreglsterwill rnessagpprolscol.TheCOMMA|,ID ths dimonnec{phases(41-45}wist each cyderthru4gh diEmnnectklnsnd a$mquen resnrection ur*il all sf ths daia has been treriSenedand $F Data Transfer phaesis conplste. A Statusphaseis expcted byth€33c93Afolbwingthe DataTransterphase{or insteadol the DataTranster pfrasswhenthe TRANSFERCOUNTregi$ercontains a yaluoof zem). At ttm start of the Statls phase,the CQI{IiAND PHASEregisteris foadedwith hex 47. Upanmr$etion of the $atus phase,the COMMAf{D FHASErcgisterwill be Wdated to hex 50, and the recoUEdstatus byte b storsd in the TARGETLUN reglstorwhere it can be read upon corrpfEtionol the connnanil.

10

3x 11 42 43

&

fFlmng hb SC$l hlr devb hs born aslodcd. Th. SilCgS ie in the disonnected state. b The Targothes,,t'ffii ssHed. The SSCO3A nowin the onneeiled s en hitiator stde. An Een$y mosagp hs'been sent to $e Taqnt. Cornmand phase has start€d, no b:ftes trandened Command phase, x bytes have been trandened. messagereceived. Save-Dda-Pointer bus notfres, Disconfiestmsae€t roe;eived, Targra has disonneded (SCSf bus free) blbwir€ a sr,lresfuf fan$sr of a Dissrned messag.. The 33C93A is now in lhe discsrneetedstde. The glC93A hs,been reselgc{edby the Terget,wtloeeSCSfhle lD mebhs the trdus }n the DESTINATHIilIfD ngirt*. Ths gtl0ggA b tw in ths omrcc'ted.asen hitids *tdo. The33Cg3Ahas rmlsad an Hentfi meesqs from the Targd uhose Log*lel.Unit Number matdns the vahn in tho TARGET LUH regisfier. The number ol bytes specified in the TRANSFERCO|JNTregista havebeentransferredtor{romthe Targstdwing a DataOu/fn phase. TheTargsthubsgun a Reclw Stdurdrmo. The 33C93A has smssfully rrceiued e Satus bytefromttreTrygetend cbred il h the TARGETLUN register. rcoeiwd a Comhassuceeesfully The&3Cg.3A mandCompldomessry fromthe Target.

45 Folbwirgcompletbnof the status{ytetransfer,a Messags ln ptr*o is expectd. Tho 33C93Aexpectsths COIilPLETEMessage Ts$et to send a COMMAFID (hex00) to irdbate u|d the scsl cornmardoperatbn 46 has ben mmplsted.Atter the 33G93Arecelyesthis COUU*UD CQMPLETEilessage, the COMMAND :l PHASEruglsteradvarpesto hex60,andll th EDIbit is "succss$ul resst,a completion'irilemrptis generated 47 The processorshoukl then read the TARGETLUN 50 regrbterto examinethe Target status.An additbnal ir,{ernlptwill thenmq.lrwhsr the SC$l hls gpssto the Bur Froe stats, or ryftenarclher REQ is asseiledto 60 bryin an hilormatbntransferpfrase(as in SCSIfinfted cornrnars), lf the EDI blt is set,the "sumessfulcomdetiorf irilernpt will be suppresseduntil the Target A "FosutTtsS6lsct-an&Tran$efesmlmrd Is aseunpd dbconn*{s fromthescsf ht8. ufienevsr a normal€ebct-arxC-Trandefmnunard b At arrytimsduringexecutbnof the Select-ard-Transfer issuedwhilethe SSCgilAis in the Confpd€d-lnitiator @mmands,an abnormalor unexpectedconCitionwill state. When the "Resume"is issued,the 33CggA cilrse ths SilCgSAto terminateth€ cotrunard,set the examinestheCOMMAND PHASEregistertodetemrirp approprise da&.tsqralifiors, ard generatea "tsrmi- whre to rs$art tho Select-ar*Transler onuftarxt nated' intemr$. lf ths terminationocarned durirg an exocutbn. Thi$ featurs, in sniur$lon wlth ttts lr,*ormdbntransfsfphaee,ths 33C93Atrei$be lsft in a ]NTERRUPT eN*H€d, ]NTERM EDIATEDISCONNECT C'gnnst#ae-dt'lm'tiatorsteto{unleesterrdnatbnwasallowesupportol rnrlti-lhrsadedor ovet@Fd UOon *re to a afikfen Taqnt dismnnsclion).Cornmard the SCSIbr.rg. terrrdnfrtiondurirg any ottur phase will result in the S{IGSSA birr€ in a Dis@rrwtad Sate. Transfercom- Tholollqilirq lable brieflydescrhestlrEvalHeettit€sof rmr-,S$,may be ussd to handb ths exce$bn by tho coMMAt{D PHASE Fgister when rezurnirg a : comrnarud tranEfsrrrhu Select-and-Transter mes$agaswith.tb Targqt.

possiblevaluesthat ThElohwiru tablesurnrnarizesths ths CoMMANDPHASEregistercan take durirq the mnuTrards,ard their meanings Selecl-ard-Transfer reletiveto commardterminatbn:

*s

ailfltis9llA

Sotr-,*nrml ' Pfp;; :

rhwtffrf

lO

BerumnafierT*tg* EeMion h eornpbte. fussme dt*1 Her*lfy qnqsagsout,Cornnrsd dt$q b expecred;an implbd Negate AcK o@llr&

g0'

Rgsuflre when C0mrnand pharo has begun FtEci asseiled). Resurne after Gommand phase or after SaveDate.Pointer message. Dat+ Stslue, or iiloceage ln phases are expeded. An implled ' Negrde Ag( oetrs.

41

42

Resume b cornplete Dirsmnnect Message h; an lmplfiedNegde ACK oocurs.

U

Resume after resdectbn by a Targd.

4$

Resurne b tranefer npr€ dala in e deta tr,*ns. ferphase. M.ly:Ipect Status or Message In as rseH.An irrplied Nqate ACK osurs.

46

Reeurne after the data phas€ has beon ompleted, elpeciling Status.phase or a Saye, Dda-Poidon0bconnu Message ln phme. An imdied ilqde ACK does NOT oeGUr.

SO:

Rsurno b oornpfde a StA,u* phcsq; en int1$i€dNogate ACK oqlris-

80

Resurae to ondete a Command GonrSote rftess€gs from tho Tsrg*t,ail irftsied $fry*e ACK o@urs.

rsWfiSffi, ESI'ol,afH 3; ,R SGC=0: . Resdedbn pfiasC ' . Serd klenttryMesssg,sIn; . RgcgivgDataSlt pfme; . Cluinto S€rd-Stafirs & ConWte; 4. Resetect-ar$Serd mmmanil;EDl.l, and SCC-O: '' . Fg,sgbc[bn

'g€; '

]

',.

,,tt

. Serd ktentis Memageln; . $Erd:o*ie,ln'Fll*sei . Chainto Serxt-Stdns-anG ; 5. lgryne-arxi-Reeivs @mmard,EDI-I, And , ,: SCC*It . Reselection phase; . Serd ldentitytriesoageln; . ReceiveDataAg phase; . Chainto Sen&Dle@nnecil-Messagn; 6. Resgle€il-arild"Ssfit oorffnard,EDI'"I, erd SCC-I: . Reseft$ctbn pheee; . Seruildentifyiltessegsln; "'sgr.dxt.Dat,a.tnf;'']i.,'.. . Ghainto Serd-Die@nne€f-t*euuege .

lf lhs resoMbn attenetllmss out d,rlng a Ressb€fiar-,xFTrarelsr cortnarfld,ATN:,b,Sgtt$ ard FliA**,6,r FESELECT-A}|STf,*$|SFEn(0* Ar{D 0B HEX} it a parityenor b &tocild on a lrwn{r,q dda bfio {erd The Rgse,bct-afSTransf,srmnsnafds inclt.ds lfp H$P-l or,HHP*l,n'dgp0: ths - Ut o$ df,ta dir,ectkln), Roeobct-end-RCegfug-Dgta arxil the Res€tect-gnd- commardwill bo tsrnindsd,sf,ld,ttle,,Sptrffiifrts status Send-Datammrnards. Thesc oorffnandscause the willtresst"ln tf$s€aBrB, ths GS{UAI{D, FHA$Sregs+r 3ilC93Ato executecertaincommonSCSItus phase shouklbe evaluatsd|o dsterminethElast succeesfusy squen€o es a Targetfolbrringa Reoelec[bnphase. compbted blp Ecctffi,sll Bhase..lfFmn€sf :$saa Thsss ph*ees ars detenninedby whlctt commar,dis phaseseorr,plste rsrmalh ard il EDI*O,tlpn a "$$S. eent; ard the ssttFE d tr,r€ bits: tho EDI bit in fiF cesslulcorrp|sqbn'intgfruF utoufdbe gsrpra.$dat thie CONTfiOL reglster; and ths SCC bit lp, thg poirfr.However,if EDI*I, no lnterrugls gernretodsnd DESTINATIOf.IlD register. The SCS| bus phase @rfirnarxtshainoccurs descrbsd abwe} {ae sotgJsncos ars surnrnarized bebw. Referto the 6mmard degcrisbneof ths Ssrd-Status-and€omrnand- Thefolbrrirq tabb sufiunarizea the posslt*evafuesthat Conplete ard Ssrd-Disconnec{-ilileseage comrnards the,CSW{I{$D FHA$E regiser scn taks &rilg,,lhe for datnlHon tlloss mqlences. Reselsfit, r co_,rffnatdg, ard thair:rrpanjryS$ re&atlv,g to'@fllrryrd tstminsttuln.$se gtfisr m$n-Hffid, 1. Reselect-ard-R€osiw comrnand, EDld),ard &scr$lons for addllbnalvafueethat can oocurwhen SCC-don'tcare: cofiunardchalningls us6d. . Ressle$bnpfrase; Csr*nend . SendldentllyMess4e ln; Phrm ttu*lng -r 'P|66,;u*Dfitg,Oiltphagn; m Ho $C$l'bu$ d€vh0 has bennr.eselectsd. The . Corplelbn interupt gg0g3Ab in the dismnnw{edstate. 2. Reselect-ard-Serd commard,EDI=0,and 10 The 33Gl9ttAhas sumessfullyreselec'tedthe SCC-dbn-lcare: Inltiator;The SCOSAic nowin {to mnectud as a Targststats. . Resebctbnphase; e0 Srs,Hsntily m$ssfrglshs beon eurcesslully . SendldsntllyMesaagotn; asntto the lniliamr. 4S . SerudDataIn phase; The, reguortod deta trengfer has been complatedi . Comdsrnr'-it intemrpt.

ffi#ffi*

+57

rg

A" Rossbct€rtsTffisf comrmtd ,ls 8s€ilffi urtlofrovera nonnaf "Rasglectand.Transef mrunard b bsued whlfe tho 33cg3A ie in the gtate.Whonthg"Resums"is isConnscilosas-a-Targot flIod, tho 3itc93A examinesthe COMMANDPHASE regtsterto&termlnewtprc to redsil the Reselect-ardTrandsr conmandsxscnsion.Thisfeature,in confurntbn 1tt{htm capabiRyto chain to other comblnatbn ootnmfiftds,albrrs tongerSCSI bus sequen€s to be eroartsd by a sirqlo command. TheloffowirqtableHlefly descrbesthe msaningof the COil|MAND PHASE register when resuming a Res6,bd-s*Tnarrcfier mmrnan* Oonxnrnd ?hrrr 10 t0

filemlrXg Resumeafter lniti&r reselectbnis compbte; slart with Hedlly lbeerye Qut. Resumesfter Hentrfymess{e out; etad with data transferphase.ll TRANSFERCOTNT is zero,rp data tander Srce oocurs.ln either sern, a chain to Er,dhsr contbindbn 6mmard canoccurif enabled.

WAIT.FOnSE[JECT-AilDRECEIVEtrc HER The ttYalt-for€elect-an&Rmeive causesthe SCSIA to Ulo ufitil il b eebctd bVan Inrliator,et whichtirTpths trlC.93Awl$ er*er tfn Targetmodeand nessage ard oorrrr*nd hto{rnatbn wS autornatkral[be reguestsd. As sr optbn, th 3tlC93Artvy be pognarnnndto diewlmn a SGSfred @rnmandis r€c€foedwfiib oor exect$Fq a Wail-fof€efecil-ar$Rgcelve@mmard. Uscd ttfr oomrfiandthereforeeliminatestfere irtomrpts utrddr mnr ooqrr after sebctbn ard after each engsSrenil SGSIbt.rs$rass, ard resuftrsin very shoil iFA lirrp &rirg SCSfreadmmrnards. hrs

wilf terporarilf supp'ressthe InBrnry and cfiEFrb beginexecutbnd a Seru&Dlsconnecil-Messago oonrmard.An irffem.rflwillthenbe generatedafterconpletbn of this conrmanC, whichrprmallywlld irdlcatea transitionto the bus fres corditbn. Rs,ferto the SsndDismnnect-Message comrnarddescriptbnfor rprg details. lf durirq executionthe messagoor commandinformatbn receivedfrcm the lnitiatoris irrualkl,the impfied receive@mmardwill be terminatedandthe appropriate status reported.In this cas€, the COnlirfnifO PHASEregistershoutcfbe red to dstsrnine whicfl phase of lhe Walt-for-$eld-ard-Receiye cornrnard wasla$ completedbeforetha ensr conditionoccnrned. A COMMANDPHASEhex valueof hex 10 indimtes thatthe3ilCgSAwaseuccessfully selected.A hexvalue of 20 indicatesthat a illessagBufasrecelvedfrom the Initiator,and whenth€ 3itC93A@ins receMrgcommard $[es, the COMMANDPHASEis set to hex 30 ard increrents with eachh[e reeived (to a nraxinuum of 3Cfor a l2-byteCDBcommant). possblevaluesthat Thefolbwirq tab'lesumrnarlzesthe the COMMANDPHASEregbtor can take drrir€ thg Wait-for-Select-ard-Rseeive cofiunard, and tfreir meaningsrehtivoto commardtennimtbn. $es:sthr comffi&rddescridbns for #lil)nel values that can occurwhenoorrrnardcfialnirq b usd. Commald Ptlrtc

s t0 2A

Hsrrtg The 33GSA has not besnrebc*ed, lTie trlC93A b in the disconnededstate. The 33G93Ahs beenguccessfrdly sebcted by rh€ krilisr. The slcg3A is rpw in the connec{edas a Targetsilate. The Hentfi me*age has hn strcessft$fr recelvsdfromthe InitiatorThs *lC$fA has begunsnmard phassby ssttingthe SCSIhs phme srtlnduw$ assertingRECI. The 33C93Ahastransfend ono flnmand bytefromthg Initidor.The SCSISTATUS mayindi,mtethe negdfor the hod to bad the commandsizo intothe OtAtll lD register. The 3ilC93Ahaetrarpfered x ommend bytesfromthe hifiabr.

|| mwas acsert€dby the lnitiatordurirgthe sebction 30 ptrmo,,ths 3rc93A will firlil execute aR imsied frscoivo lrteosagaOi$'oommandto get the f&ntlfy rrcsry I'romthe lnitiator,beforecor*inuingon witir 31 tb ir$id fresfve Conrnanf to receivetho SCSI lrilormatbn.TheSCSI@rnrilardirilonmt*)n cofn$fiand tG0ts' wifl be silored In the CDB regstors (hex Arftroosatm b 0E),andlt a wlH IDENTIfVrnassage 3x F rumfusd,ils,if bo earedin tfie TARGETLUNreglster {tpx #rese 0n. Tfp nun$er of conunard bytes f€$rs€*sdby ttp 33c93A is deterrninedby the scsl A "ResumeWait-for-Select-ard-Receive' commardb grqp oadsin ttE first byteof the cDB. assumed whenever a normal Ytfaft-lor-Sebct-ardAfrer ths 33C93Ais sebcted ard recsivesall valid Receive"orrnarrd ls issuedwhilstho 3s0ggAis in the state. When the ficsufns' is mmrnard ard rnessagleinfonnatbn, a 'successful Connected-as-a-Target mfpletbn'intem4il willnonnallybe generated to albrr issued,the 33C93Aexaminesthe COMMANDPHASE th hcsf procossorto read out ard interpretthe SCSI registerto determinewhere to restartthe t/tlait-forCU8. lbwever, by $ettirgtho EDIbil prbr to issuinga Select-ard-Receivecommardexecutbn.Thisfsature, withthe capabilltyto chainto othercomWeil-for-$ebd-arxl-Racelv€ cor,nmand, the 33CggAis in conjurrction allqffsbngprSC$l bussequetrces sr$lod b Frform an automatbdisonnect when a binationcommaFtds, SCSf nad oomrnandb rmeived. Therefore,when to be executedby a singlecommand. EDI-I and the lst CDB byte recsivedcontain$a S, lD, or lz-byto readoorrnandcode,thenthe 33CggA {ff

AmSSSA

n.-::lH'ffi*j':.1'*'besthemoant'gofthe2.cDB12bit0=.1,bit1-0:Thesta uuMMANuFl-fASrregtsterwhen rasuming a Wait-for. Bsnt, fofbwed.,by e Linked,( .Solect-ard-Rscsive cohnrarU: Fortbn of Wait;for-$elect-and-l Cormard

qn,qo,:

lil*, 10

Resume after selecilbn by the Initiator is comp{eto; start with Hernify l#essage Out if ATN b asseried, otherwbg, starl ,with mmmand phase.

ilesurne after a rns'Bagsour; efrpckrhe recsivedmessagoin the TAHGETLUNregisrer for a valH ldentifymsssage Resumeaftor Hentifymessqe out. Startwith commandphase. Resumoaltsr the &?CggAhes transfened1

30 31

*nt"nsun"-irdili;iti"il.'iiil;;;;;

point is uEedonff whon an unknowngroup 6de heg bsen detectedin Advanoedlr,lode, and the commardsize has been loadedinto

,

,.

th?ow! f?tg.giltet ,, '

,

SEI{D_STA''*.AND€O$'*AN*GOM'LETE 'v nrlr 'r'vr"rr''rrrv-\'t/ilrr-rr*rE (0D HHx)

:?JiliilT_ffi":?ilf$J COmrnand. ,-,^. . g. CDBIA , r_h,r bitO--i, bifl ot: The slal 8ent, folbtrd by a Lirked-Corn

Flag messruE (08 hsx). A chain to the co fetch Fortion of Wait-for-select-and-Receh O€Cur8to fotcfi ths next CDB from ths I 3elC93A frd eregutttn p for that mrnmard.

A Serd-Status'and.Cqry6nd.Compfere cor

may be terminatsd by ffi asserted,,wh€fi H, when a Disconnector ffeeet connnard b isguer The forfowingtabre summ,ariaesth

theco[{MANDpHAsEregreter Send-Status-ard-Comman&Com thgir rrpanings relatiig to cornlni

i"neserd.sarus-and-commard-comprere command St#ffiXi:il,; vglid in the Targetrola, ard ls usedto mrwete a ::Tr"ffi"#ffiS

is SCSIoperationby transfeningthe appropriate Command status informationto the Initiatorprbr to disconnection Phase from fthar thescsl bus.This@mmardatsosupportslirs<ed scsl 00 l*o oB*ratlrn occut?s operatbnsby optionallyallowinga'rinreCco1r11xgrd: found lo be a$ertsd. compfetemsssageto bo sent after the status is S0 Srq$dphss'iransfar c transfened.Linkedconnnandoonpletefftsssagesare ilr'\' comrnincGomptrile r corilrolledby tho CDB1Zregisterwith Oimmat COre. gerod. spord to the standardlinkedonrnand controtbits in 6t ti;k; command com thecDB il;t"d:'

A "Resume send-srarus-and-( f,Xff:-il,T$i5ffiif,ff:l$ffi;ffyg';ltffi;

byre which witfrhen berransrened across rhe I sraru$

scsl h.rs.Also,the finkcontrorbits from the current ssil:lll-ffn:ffi..k$iffi'", cDB mustbebadedintothecDBr2registertoensrrre while the 33c93A is in the Gc

rhar rhecorrqq ocours" Nore rhar rhebils tleyer,rco used by the 33C93Aar,eidsnticalin meaningto the il:y,ilftsJffixffii3;xi:trfl SCSIslandardlinkcontrotbits.ThefE${procgls_or may simplyloadths controlbytefromtheicunentSCSIcontmandinto cDBlz to grstthe correctfurKtbn. As lhe

where to restart the $end_Sti Comptete ,;;;nd'execution confrrrstbnwittrthe capabilityto r

phasecompleted.

The{otbwingtabtebrtefrydescrlbe

-cdrrrilNb command execution-prosfssses, tn, PHASEregisterwitt b€ updstedto indicatethe la$t ffiitrfrffiftffi,:ffij

rhepossible sequencss caused bythiscomrnand are 3ffilYffi":ffitrH1lil,rf: asfollows:

'

r,

1. CDB12bit0*O,gitl-dont care:The statusbyte in CDBll is sent,folloeredby a CommandComptete msssage (00 hex). A isuccessfulcompreiionl

,l

,,

cornmand phrca

irnsitwtA

s0

-t-

.

',

,t,

I

,

,

,,

-

ile*r Rosumesfter status F

-il ain to tr :ll rf$*"*"*"Xffi ;H',f

/*s0

gsilsDaco-ilH$cr.$EssAcE (0EHEI(} T[g $erxt-Dbmrred-Messagesmmard is a Targetrole coFunArdnrhbhmay be usedto disqonnsctlrom the SCS| bus at sny time &rrirq a SCSI comrnand Eogrsnce.T.hbwrlrnard mnsistsof ssrdirg a DisconbVphy$caldlsconnactbn @ messagqb.yto,fosouved fromtfrebus (SCSIbusfree).An internr$b generated to bus free occurs.As an optbn, a only afiertnansfrion rrrss4e will automatbal$be sent Save-Data-fuirilgr meseagpwheneverthelDl blt is beloretho Discormect s6t prbr to iss rg thls cornrTlard.

A Send€isosnned-4lcssap eofirrtqff rny be terilSnatedbyffi assertedwhsnHA'.l, orwhena Disconnector Resetcomrnardis issusd. Thefolbwingtablssupqtadzesthepoaslblevafuesthst th6 COMMANDPH SE registercan take duringthe relative ard thslrrneanings Ssrd-Disconnscf-Messagn, de*ripto oornmadterminatbn.Sse olherconsnanC tions, for d$tbnal valuss ,that can o6ur whgn camrmrd chainlrEis used.

The COMMANDPI{ASE register b updded dldrq exocutkmof ttle Son&Dismnnoct-Messqncommsnd to irdicatebusSrasegtdtrs,Aftera,SarrsrDataP.ointer rns$ agpb sert, thECOMMANDPHASEwill be set to 4lH. Afterthotllsconnect;ressagetransfer,this rogister will bs updatsd$ 4AH,ard dler disconnedbnthe cortaina 4i]H. COMIIANDPFIASEreglster,will

Cotrnrald Phesc 00 41 42

{r

Ithnlng No operabn occuned; beically, Iffi was fourd to be asserted. The Saw'Date-Pointermesage was transferred. The Discqn@ messegewastrensferred. The bus fre ddo oeurrd afrerthe Dlsconneci messagowastrandened.The33C93Ais nowin the diwnnec*ed ltale.

CHARACTERISNCS ETECTR,ICAL ABSOLUTElfAxllf UMnAT|hfgS

-0.5 V to +7.0V Voltageon anyprinwith r*pect to GND 0 to 70 deg. C temperature Qpemting -65 to +125 deg. G Storagolenperature 5@ mllll fuwor dbslpatbn lnpr$Statb DischargeProtectbn 2000 V prn lo ptn

'#f,iii#; X':,H#;, i'##::,ffiffi

at or eblp lhesEfiitrtfsis rrit imf,iod. *psuro to atrnllv/rel maxlnun ratirrystar extendedprbds nay atfoc/.devicn rc,i&iw.

DC OPERATINGCHARACTERISTICS Ta - Ob 70"C, VCC - +5 Vt0.25 V, GND - 0 V

S.ymbqf

Gondltbng

chrrd|rldb

VS'l-.4to \rcC VOttT - .5 to VCO VOtT-.4toVCC

lnputLo*age SQSfotrqn,ttLedc4c {lnactive} qupul Leakage(Tri-State) lnpu Hbh Voltage

v V

v 0.5 0.4 20

ilSO ,

Am3{ffi91}A

v v v mA

il) . -4t10ttA il} - 48.0rnA t) - 4.0 fiiA Ta - +?S*