Instruction/ maintenance manual of the product Ultra 160 Seagate
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Parallel SCSI Interface Ultra 160 Ultra 320.
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Parallel SCSI Interface Ultra 160 Ultra 320.
©2006, Seagate T echnology LLC All ri ghts rese rved Publication number: 1002 93069, Rev . A March 2006 Seagate and Seagate T echnology are register ed trad emarks of Seagate T echnology LLC. SeaT o ols, SeaFONE, Se aBOARD, SeaTDD, and the W ave logo are either registered trad e - marks or trademarks of Seaga te T echnology LLC.
Parallel SCSI Interface Product Manual, Rev. A iii Revision st atus summary sheet Revision Date Writer/Engineer Sheet s Affected Rev . A 03/27/06 C. Chalup a/G .
iv Parallel SCSI Interface Product Manual, Rev. A.
Parallel SCSI Interface Product Manual, Rev. A v Table of Contents 1.0 Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 How to use this interface manual .
vi Parallel SCSI Interface Product Manual, Rev. A 2.5.35 Receive setup time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 2.5.36 Receive REQ(ACK) period tolerance . . . . . . . . . . .
Parallel SCSI Interface Product Manual, Rev. A vii 2.12.8.3 QA S_REQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.12.8.4 HO LD_MCS . . . . . . . . . . . . . . . . . . . . . . .
viii Parallel SCSI Interface Product Manual, Rev. A 3.7.1 DATA phase overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 3.7.2 DT DATA IN phase . . . . . . . . . . . . . . . . . . . . .
Parallel SCSI Interface Product Manual, Rev. A ix 4.3.16 SYNCHRO NOUS DATA TRANSFER REQ UEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 4.3.16.1 Target initiated SDTR negotiation . . . . . . . . . . . . . . . . . . . . . . . . . .
x Parallel SCSI Interface Product Manual, Rev. A 7.3.1 Status precedence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 7.4 Command examples. . . . . . . . . . . . . . . . . . . . . . .
Parallel SCSI Interface Product Manual, Rev. A xi List of Figures Figure 1. SCSI client-server model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Voltage and current definitions .
xii Parallel SCSI Interface Product Manual, Rev. A.
Parallel SCSI Interface Product Manual, Rev. A 1 1.0 Interface requirements 1.1 How to use this interface manual This manual pr ovides a descr iption of the SC SI 1 interface protocol and some general timing information as implemented by Seagate p roducts.
2 Parallel SCSI Interface Product Manual, Rev. A 1.1.1 Scope of SCSI standards Figure 1 uses a represent ative set of specifications to show the functional partitio ns and the relationship s among SCSI sta ndards applicable to drives covered by this manual.
Parallel SCSI Interface Product Manual, Rev. A 3 1.1.2 A pplicable st andards The following ANSI st andards should be r e ferenced for more det ails about SCSI system standards o f opera - tion: • S.
4 Parallel SCSI Interface Product Manual, Rev. A Figure 2. SCSI client-server model 1.2.1 Glo ssary aborted command —A SCSI command that has been ended by abor ting the task crea ted to execute it.
Parallel SCSI Interface Product Manual, Rev. A 5 command descriptor block —A structur e used to commun icate a command fr om an application clie nt to a device server . Command structures of 6, 10, 12, or 16 bytes ar e used, but a new variable length command structure has recently been intro duced.
6 Parallel SCSI Interface Product Manual, Rev. A double transition (DT) —The latching of dat a on both the assertion edge and the negated edge of the REQ or ACK signals. driver —The circuitry used to contr ol the state of the bus. enabled t ask st ate —The state of a t ask that may complete at any time .
Parallel SCSI Interface Product Manual, Rev. A 7 I/O operation —An operation defined by an unlinked SCSI co mmand, a series of linke d SCSI commands or a task manageme nt function.
8 Parallel SCSI Interface Product Manual, Rev. A nexus —A relationship between a SCSI initiato r port and a SCSI target port, logical unit, or queue t ag that begins with an initial connection and ends with th e comple tion of the associated I/O process.
Parallel SCSI Interface Product Manual, Rev. A 9 protocol servic e request —A call to the lower level pr otocol service layer to begin a prot ocol service transac - tion. protocol servic e response —A reply from the upper level protocol laye r in response to a protocol service indi - cation.
10 Parallel SCSI Interface Product Manual, Rev. A service delivery tra nsaction —A request or response sent throug h the service delivery subsystem. signal —(n) A detectable asynchronous event possibly acco mpanied by descriptive data and parameters.
Parallel SCSI Interface Product Manual, Rev. A 11 third-pa rty command —A SCSI command which requires a logical unit within the targe t device to assume the initiator role and send a SCSI command to a SCSI target por t device.
12 Parallel SCSI Interface Product Manual, Rev. A 1.3 Physical interface cha racteristics The physical interface characteristi cs (cables, connectors, electrical desc riptions, termination requ irements, etc.
Parallel SCSI Interface Product Manual, Rev. A ) 13 2.0 SCSI bus This manual discusses only the “lo g ical” and timing char acteristics of the SCSI system and interface. A genera l description of th e SCSI bus physical characteristics (voltages, connector configurations, pinouts, etc.
14 Parallel SCSI Interface Product Manual, R ev. A ) The Host Adapter/Initiator must be identified by on e of the 16 SCSI Device IDs (usually 7, which is highest arbi - tration priority). Make sure that none of t he devices on the SCSI bus have duplicate IDs.
Parallel SCSI Interface Product Manual, Rev. A ) 15 2.1 SCSI bus signals overview Information transfer on the SCSI bu s is allowed between only two SCSI devices at any given time except dur - ing MESSAGE IN PHASE when QAS is enabled.
16 Parallel SCSI Interface Product Manual, R ev. A ) During the SELECTION PHASE, RESELECTION PH ASE, ST DA T A PHASE, COMMAND PHASE, MESSAGE PHASE, and ST A TUS PHASE, this signal is referred to as DB(P_CRCA) and is sour ced by the SCSI device port driving the Da ta Bus.
Parallel SCSI Interface Product Manual, Rev. A ) 17 When information unit transfers are enabled, the P1 si gnal shall be cont inuously negated by the SCSI device driving the D B(15-0) sign als and shall b e ignored by the SCSI d evice receiving the DB(15-0 ) signals dur ing DT DA T A phases.
18 Parallel SCSI Interface Product Manual, R ev. A ) Figure 3. V olt age and current definitions Figure 4 defines the signa ling sense of the voltages ap peari ng on the – signal and + signal lines as follows: a. The – signal ter minal of the dr iver shall be ne gative with respect to the + signal terminal for an asserte d state.
Parallel SCSI Interface Product Manual, Rev. A ) 19 2.4 Signal sources Ta b l e 3 indicates the type of SCSI device allowed to sour ce each signal. No attempt is made to show if the source is driving asser ted, driving negated , or is released. All SCSI device drivers th at are not active source s shall be in the high-impedan ce state.
20 Parallel SCSI Interface Product Manual, R ev. A ) 2.5 SCSI bus timing Unless otherwise indicated, the delay time measuremen t s for each SCSI device, defined in p aragraphs 2.5.1 through 2.5.60 shall be calculated from signal conditions exis ting at that SCSI devi ce’ s own SCSI bus connec - tion.
Parallel SCSI Interface Product Manual, Rev. A ) 21 T able 5: SCSI bus dat a and information phase ST timin g values [1] SCSI bus timing values specified by the maximu m transfer rate for the given range shall apply even if a slower transfer ra te within the given range is ne gotiated.
22 Parallel SCSI Interface Product Manual, R ev. A ) [2] Cable skew is measured at each SCSI device conn ection with in the same bus segment with the transmit- ted skew subtracted from the received skew . [3] Calculated assuming timing budget shown in T able 9.
Parallel SCSI Interface Product Manual, Rev. A ) 23 T able 7: T ransmit SCSI bus dat a and information phase DT timing values [1] SCSI bus timing values specified by the maximu m transfer rate for the given range shall apply even if a slower transfer ra te within the given range is ne gotiated.
24 Parallel SCSI Interface Product Manual, R ev. A ) T able 8: Receive SCSI bu s data and information phas e DT timing values [1] SCSI bus timing values specified by the maximu m transfer rate for the given range shall apply even if a slower transfer ra te within the given range is ne gotiated.
Parallel SCSI Interface Product Manual, Rev. A ) 25 T able 9: SCSI Fast -160 and fast 320 non-compensat able timing budget in nanoseconds Item Fast-160 Fast-320 Comment s REQ(ACK) period 12.
26 Parallel SCSI Interface Product Manual, R ev. A ) 2.5.1 Arbitration de lay The minimum time a SCSI device shall wait from asserting BSY for arbitrat ion until the data bus can be exa m - ined to see if arbitration has been won (see Sectio n 3.1.2 ).
Parallel SCSI Interface Product Manual, Rev. A ) 27 When information unit transfers are bein g used with syn chronous transfers, the A TN receive setup time is the minimum ti me required at the receiv.
28 Parallel SCSI Interface Product Manual, R ev. A ) 2.5.12 De-skewed dat a valid window The minimum difference in time a llowed between the rising or falling ed ge of a “1010.
Parallel SCSI Interface Product Manual, Rev. A ) 29 2.5.21 Dat a releas e delay The maximum time for a SCSI initiator port to releas e the DA T A BUS, DB(P_CRCA), and/or DB(P1) sig nals, following the transition of the I/O signal from false to true. 2.
30 Parallel SCSI Interface Product Manual, R ev. A ) DB(P1) signals. For p aced dat a transfers negative valu es as measured at the d evice conn ector are ac commo - dated by skew compensation in the receiver . Receive hold time measur ed at the device connecto r shall not exceed the skew correc tion range.
Parallel SCSI Interface Product Manual, Rev. A ) 31 2.5.40 Receiver amplitud e time skew The maximum time shif t of SCSI bus si gnals caused by the dif f erence in re ceiver switching de lay of a minimum amplitude signal ver sus a maximum amplitu de signal.
32 Parallel SCSI Interface Product Manual, R ev. A ) pensation. 2.5.49 Skew correction range The minimum skew correction capability of the receiver of a signal on the DA T A BUS or DB(P1) relative to the ACK or REQ signal as measured at the receiver’s conn ector .
Parallel SCSI Interface Product Manual, Rev. A ) 33 The minimum time that a SCSI t arget port shall negate the REQ signal while using synchronous transfers or paced transfers, pr ovided it is not transitioning P_CRCA during dat a grou p transfers.
34 Parallel SCSI Interface Product Manual, R ev. A ) SE SCSI devices with data transfer rates up to a nd including Fast-20 shall use the measur ement points defined in Section 9 of ANSI standard SPI-4, for the m easurement of the timing values.
Parallel SCSI Interface Product Manual, Rev. A ) 35 Figure 8 shows an example of transfers with a negotiated tr ansfer period of 6.25 ns at the receiving SCSI device’s connector .
36 Parallel SCSI Interface Product Manual, R ev. A ) Figure 7. DT synchronous trans fer example Figure 8. Paced transfer example 2.8 Paced transfer on a SCSI bus A SCSI bus that support s paced transfers has add itional dr iver and receiver functions re quired over those used with synchronous transfe rs or asynchronous transfers .
Parallel SCSI Interface Product Manual, Rev. A ) 37 The receiver skew compensa tion and clock shif ting adjust the timing relationship between the clocking signal (i.
38 Parallel SCSI Interface Product Manual, R ev. A ) 2.10 ST DA T A phase parallel transfers The format of dat a transmitted during ST DA T A phases consists of dat a and protection. Parity generation and checking give some error detection protection in the ST phase data.
Parallel SCSI Interface Product Manual, Rev. A ) 39 The iuCRC shall be used to prot ect all SPI inform ation un its. The SCSI device that origina tes the SPI informa - tion unit sends the necessar y pad bytes and iuCRC fields. An iuCRC interval may also be specif ied.
40 Parallel SCSI Interface Product Manual, R ev. A ) If the responding negotiation message contains values the origi nating port does not support, the orig inating port shall respond with a MESSAGE REJE CT message. 2.12.2 When to negotiate Each port shall maint ain a negotiation required flag for each other po rt.
Parallel SCSI Interface Product Manual, Rev. A ) 41 When negotia ting, the respon ding port sha ll respond with values that are a subset o f the values in the ori ginat - ing message as indicated in T able 12 (e.
42 Parallel SCSI Interface Product Manual, R ev. A ) 2.12.4 T ra nsfer agreeme nt s The transfer agreeme nts that are in ef fect for various combinations of field values are describe d in T able 13 .
Parallel SCSI Interface Product Manual, Rev. A ) 43 2.12.5 T ran sfer period fa ctor The T ransfer Period Factor field select s the transfer per iod and determin es which transfer rate’s timing values in T ables 5 , 6 , 7 , and 8 shall be honored, provided that REQ/ACK OFFSET is gr eater than 00h.
44 Parallel SCSI Interface Product Manual, R ev. A ) 2.12.6 REQ/ACK offset The REQ/ACK OFFSET field de termines the maxim um num ber of REQs allowed to be outst anding before a correspond ing ACK is received at the SCS I target port during synchronou s or paced transfers.
Parallel SCSI Interface Product Manual, Rev. A ) 45 2.12.8 Protocol options The protocol options fie lds affect th e protocol used betwee n the ports. The SCSI t arget port uses the protocol options bits to indicate to the SCSI in itiator port if it agrees to enable th e requested pr otocol options.
46 Parallel SCSI Interface Product Manual, R ev. A ) Ta b l e 19 de scribes the bus phas es resulting from IU_REQ changes. 2.12.8.2 DT_R EQ The SCSI initiator port shall set DT_REQ to one to requ es t that DT DA T A phases be enabled.
Parallel SCSI Interface Product Manual, Rev. A ) 47 Ta b l e 20 defines valid co mbinations of HOLD_MCS and other fie lds. 2.12.8.5 WR_F LOW The SCSI initiator port shall set WR _F LOW to one to indicate that the SCSI target port should enable write flow control durin g write streamin g.
48 Parallel SCSI Interface Product Manual, R ev. A ) 2.12.9 Negotiable field combin ations Not all combinations of the negotiable fields ar e valid. On ly the combinations defined in T able 20 shall be allowed. All other combinations of th e listed fields are reserved.
Parallel SCSI Interface Product Manual, Rev. A ) 49 2.12.10 Messa ge restrictio ns PPR may be originated by SCSI initiator port s but shall not be originated by SCSI t arget ports. If bus expande rs are present, SCSI initiato r port s should only use PPR when requesting values not att ainable via WDTR and SDTR (e.
50 Parallel SCSI Interface Product Manual, R ev. A ).
Parallel SCSI Interface Product Manual, Rev. A 51 3.0 Logical characteristics The operations of th e SCSI bus as described in this se ction are supported by the dr ive as specified in each individual dr ive’s Product Manu al. The dr ive always functions as the target unless oth e rwise stated.
52 Parallel SCSI Interface Product Manual, Rev. A a. af ter any bus reset event. b. af ter a transceiver mode change reset event. c. after an Abort T ask managem ent function is successfully re ceived by a SCSI target port; d. after an Abort T ask Set ma nagement fu nction is successfully received by a SCSI target port; e.
Parallel SCSI Interface Product Manual, Rev. A 53 SCSI devices with arbitration fair ness enabled shall main ta in a fairness register that records the SCSI IDs of devices that ne ed a chance to arbi trate (see Se ction 3.
54 Parallel SCSI Interface Product Manual, Rev. A 3.1.2.2 QAS p rotocol Quick Arbitration and Selection (QAS) a llows a SCSI target port with an information unit tran sfer agreement in effect an d QAS enabled (see Section 4.
Parallel SCSI Interface Product Manual, Rev. A 55 4. If the SCSI initiat or creates an att ention condition, the SCSI target port sh all go to a MESS AGE OUT phase, receive all the message by te s, and cause an unexpected bus free by generating a BUS FREE phase (see Section 3.
56 Parallel SCSI Interface Product Manual, Rev. A Refer to Section 3.4 for a descript ion of the fairness algori thm which applies during SELECTION and RESE - LECTION phases.
Parallel SCSI Interface Product Manual, Rev. A 57 3.2.1.1. 4 Se lection usin g attent ion condition timeout procedure T wo optional selec tion timeout proc edures are sp ecified for clearing the SCSI .
58 Parallel SCSI Interface Product Manual, Rev. A (a) Optionally , the initiator shall assert the RST sign al (see Section 5.3); (b) Optionally , the initiator shall continue asserting the SEL signal and sh all release the Data Bus, DB(P_CRCA), or DB(P1).
Parallel SCSI Interface Product Manual, Rev. A 59 glitch may cause the BSY signal to appear false for up to a round-trip prop agatio n delay following the release of the BSY signal by the in itiator .
60 Parallel SCSI Interface Product Manual, Rev. A 3.5 Information transfer phases The COMMAND, DA T A, ST A TUS, and MESSAGE phases are grouped together as information tr ansfer phases because they are all used to transfer dat a or control information via the data bus.
Parallel SCSI Interface Product Manual, Rev. A 61 Synchronous transfers shall only be used for negotiated tran sfer rates less th an or equal to Fast-80.
62 Parallel SCSI Interface Product Manual, Rev. A hold time afte r the assertion of the REQ signal. The target shall assert the REQ signal for a minimum of one transmit assertion period. Th e targe t may then negat e the REQ signal and change or release th e DB(7- 0,P_CRCA) or DB(15-0,P_CRCA,P1) signals.
Parallel SCSI Interface Product Manual, Rev. A 63 3. shall delay at least one transmit setup time; 4. shall transition the ACK sign al; 5. shall hold the DB(15-0) signals valid for a t least one transmit hold time; 6. shall not change the ACK sign al for a mini mum of one tran smit assertion period; and 7.
64 Parallel SCSI Interface Product Manual, Rev. A ABORT T ASK message (see Section 4.5.2 ) to the t arget. The target shall send a SPI L_Q/SPI sta tus informa - tion unit pair to the initiator wi th a CHECK CONDITION status and a sense key set to Ab orted Command for the task associated with th e received ABORT T ASK message.
Parallel SCSI Interface Product Manual, Rev. A 65 2. read the valu e of the P_CRCA signal within on e p CRC receive hold time of the transition of the REQ signal; and 3. respond with an ACK tra nsition. If the I/O signal is false (i.e., tr ansfer to the t arget), to transfe r the data field, the initiator: 1.
66 Parallel SCSI Interface Product Manual, Rev. A Note. The above requirement s in steps 6), 10), and 14) to not wait for the ACK transition correspondin g to the previous REQ tr ansition were not present in th e SPI-3 st andard.
Parallel SCSI Interface Product Manual, Rev. A 67 Pad field dat a and pCRC field dat a are tran sferred using the same negotiated transfer peri od as the dat a field data. The target may continue to send REQs, up to the negotiated offset, fo r the next data group.
68 Parallel SCSI Interface Product Manual, Rev. A The tar get shall read the value of th e DB(15-0) signals within one re ceive hold time of the transition of the ACK signal. The initiator shall use the pad bytes, if any , in the generation of the transmit ted pCRC.
Parallel SCSI Interface Product Manual, Rev. A 69 If the ret ain training infor mation is enabled, a trainin g pa ttern shall be transferre d at the start of the first DT DA T A phase for each dat a transfer direction af ter the retain training infor mation is enabled.
70 Parallel SCSI Interface Product Manual, Rev. A 4. simultaneously assert and negate P1, P_CRCA, and DB (15-0) signals at twice the negotiated transfer period (i.e., simult aneously repeat a 1 100b bit patt ern 12 times on each signal) while asserting and negating REQ at the negotiated transfer per iod 24 time s [e.
Parallel SCSI Interface Product Manual, Rev. A 71 The SCSI initiator port shall b egin the section A of its training p attern independent of th e start of the SCSI ta r - get ports training pattern if it det ects the SEL and MSG true, and C/D and I/O false on the first assert ion of the REQ signal.
72 Parallel SCSI Interface Product Manual, Rev. A The data inva lid state shall have at least one tran sition of P1 before changing states. The minimum dat a invalid time is four transfer periods. This ensures a maximum r un length of three cycles for P1.
Parallel SCSI Interface Product Manual, Rev. A 73 The SCSI target po rt shall begin p acing tr ansfers only after meeting all the follo wing: • signal restric tions betw een informatio n transfer p hases listed in Section 3.10 ; • the signal restrictions between a RESELECTION phase and a DT DA T A IN phase listed in Section 3.
74 Parallel SCSI Interface Product Manual, Rev. A and (e) shall hold the DB(15- 0) signals valid for a minimum o f one transmit hold time. If the I/O signal is false (i.
Parallel SCSI Interface Product Manual, Rev. A 75 T able 22: Wide SCSI byte order If the last information byte transferred does not fall on the DB(15-8) signals for a 16-bit wide tr ansfer , then the values of the remaining highe r-numbered bit s are un defined .
76 Parallel SCSI Interface Product Manual, Rev. A 3.7.3 DT DA T A OUT phase The DT DA T A OUT phase allows the SCSI t arget port to request that data b e sent from th e SCSI initiator device to the SCSI target device usin g DT data transfe rs.
Parallel SCSI Interface Product Manual, Rev. A 77 A QAS-capable SCSI initi ator port shall assert ACK for a minimum of one QAS non-data phase REQ(ACK) period.
78 Parallel SCSI Interface Product Manual, Rev. A d. When switching the Data Bus or DB(P_CRCA) signal dire ction from out (SCSI initia tor port driving) to in (SCSI target port driving), the targ et s.
Parallel SCSI Interface Product Manual, Rev. A 79 The final information trans fer phase is normally the MESSAGE IN phase wher e a DISCONNECT or T ASK COMPLETE message is transferred, followed by the BUS FREE phase.
80 Parallel SCSI Interface Product Manual, Rev. A 3.1 1.4 Phase sequences for physical r econnection or select ion without us ing attention condition with info rmation unit tran sfers ena bled The seq.
Parallel SCSI Interface Product Manual, Rev. A 81 3.1 1.5 Phase sequences for physical selection us ing attention condit ion with information unit transfers enabled The sequences for a selection with attention cond ition while an information unit transfer agreement is in effect shall be as shown in Figure 14 .
82 Parallel SCSI Interface Product Manual, Rev. A For COMMAND, MESSAGE, and ST A TUS phases, the DB(P_C RCA) signal shall indicate odd parity fo r DB(7- 0). The DB(P1) signal shall not be checked. For ST DA T A phases, the DB(P_CRCA) signal shall indicate odd p arity for DB(7-0).
Parallel SCSI Interface Product Manual, Rev. A 83 4.0 Message system specification SCSI protocol messages a llow communication between a SCSI initiator port and a SCSI targe t port for the pur - pose of link management.
84 Parallel SCSI Interface Product Manual, Rev. A T able 24: Message format 4.2.1 One-byte messages One-byte messages consist of a single byte transferred duri ng a MESSAGE phase. The byte’s message code determines the message t o be perfor med as defin ed in T ables 27 , 40 , and 45 .
Parallel SCSI Interface Product Manual, Rev. A 85 T able 26: Extended Message Code s 1. The EXTENDED MESSAGE ARGUMENTS are specifie d within the Extended Message Descriptions in Paragraphs re ferenced in T able 27 .
86 Parallel SCSI Interface Product Manual, Rev. A Key: M = Mandatory support O = Optional support NS = Not supported IN = SCSI target port to SCSI initiator port O UT = SCSI Initiator port to SCSI target port Y es = SCSI Initiat or port shall cle ar the attentio n condition be fore last ACK of the Messag e Out phase.
Parallel SCSI Interface Product Manual, Rev. A 87 4.3.2 DISCON NECT The DISCONNECT message is sent from a SCSI t arget port to inform an initiator that the t arget plans to do a physical disconnect by releasing the BSY signal, and that a later physical reconnect is going to be required in order to complete the current task.
88 Parallel SCSI Interface Product Manual, Rev. A Only one logical unit number shall be identified per t a sk. The initiator may send one or more IDENTIFY mes - sages during a task.
Parallel SCSI Interface Product Manual, Rev. A 89 4.3.5 INITIA TOR DETECTED ERROR The INITIA TOR DETECTED ERROR message is sent from an initiator to inform a ta rget that an error h as occurred that does not preclude the t arget from retrying the task.
90 Parallel SCSI Interface Product Manual, Rev. A It is recommended that th e targe t not attempt to move the data pointer o utside the range addressed b y the command.
Parallel SCSI Interface Product Manual, Rev. A 91 T able 32: MODIFY BIDIRECTIONAL DA T A POINTER message format 4.3.1 1 NO OPERA T ION The NO OPERA TION message is sent fr om an initiator in response to a t arget’ s request for a message when the initiator does not currently have any other valid message to send.
92 Parallel SCSI Interface Product Manual, Rev. A 4.3.12 P ARALLEL PROTOCOL REQ UEST P ARALLEL PROTOCOL REQUEST messages (see T able 33 ) are used to negotiate a synchronou s data trans - fer agreement, a wide da ta tran sfer agreement, and se t the protocol options betwe en two SCSI devices.
Parallel SCSI Interface Product Manual, Rev. A 93 See Section 3.5 for an explanation of the di fferen ces between ST and DT data transfers. The REQ/ACK OFFSET value is chosen to pre vent overflow conditions in th e port’ s receive buf fer and offset counter .
94 Parallel SCSI Interface Product Manual, Rev. A T able 34: V alid protocol options bit combinations A Parallel Protocol Request agreement applies to all logical units of the two SCSI d evices that negotiated agreement.
Parallel SCSI Interface Product Manual, Rev. A 95 be changed. Each SCSI device when transmitting data shall respect the negotiated limits se t by the other's P ARALLEL PROTOCOL REQUEST messa ge, but it is permit ted to transfer dat a with larger periods, smaller synchronous REQ/ACK of fsets, or both.
96 Parallel SCSI Interface Product Manual, Rev. A If an abnormal condition p revents th e target from respond ing with a P ARALLEL PROTOCOL REQUEST mes - sage or with a MESSAGE REJECT message, then bo.
Parallel SCSI Interface Product Manual, Rev. A 97 4.3.16 SYNCHRONOUS DA T A TRANSFER REQUEST Synchronous Data Transfer Req uest (SDTR) messages (see T a ble 36 ) are used to negotiate a synchronous data transfer a greement between two SCSI devices.
98 Parallel SCSI Interface Product Manual, Rev. A a. after a HARD RESET ; b. after a T ARGET RESET message; c. after a power cycle; and d. af ter a change in the transceiver mode (e.
Parallel SCSI Interface Product Manual, Rev. A 99 4.3.16.1 T arget initia ted SDTR negotiation If the ta rget recognizes tha t SDTR negotiation is req u ired, it send s an SDTR message to the initiator .
100 Parallel SCSI Interface Product Manual, Rev. A 4.3.18 WIDE DA T A TRANSFER REQU EST WIDE DA T A TRANSFER REQUEST (WDTR) m essages (s ee T able 38 ) are used to negotiate a wide dat a transfer agreement between two SCSI devices.
Parallel SCSI Interface Product Manual, Rev. A 101 fer agreeme nt sha ll remain intact; b. If a WDTR message fails for any o t her reason, the prior synchronous data transfer agreement shall remain intact; or c.
102 Parallel SCSI Interface Product Manual, Rev. A get causing an unexpe cted bus free. The in itiator shall a ccept such action as abortin g the WDTR negotiat ion, and both SCSI de vices shall go to e ight-bit data tr ansfer mode for data tra nsfers between the two SCSI devices.
Parallel SCSI Interface Product Manual, Rev. A 103 When a tar get does a physical re connection to an initiator to continue a t agged task, the Simple Queue mes - sage shall be sent following the Identify message to resum e the I_T_L_Q nexus for the task.
104 Parallel SCSI Interface Product Manual, Rev. A 4.4.3 HEAD OF QUEUE See T able 42 for the format of the Head of Queue message. T able 42: Head of Queue message f o rmat The Head of Queue message specifies that th e task shall be placed in the task set as a Head of Queue t ask.
Parallel SCSI Interface Product Manual, Rev. A 105 4.5 T ask management messages Ta b l e 45 lists the codes used for me ssages that manage t asks. Details about these t ask management mes - sages is given in subsect ions following the table.
106 Parallel SCSI Interface Product Manual, Rev. A 4.5.3 ABORT T ASK SET The ABORT T ASK SET message is define d in the SCSI Architec ture Model-4 st andard. In addition to the requirement s in the SCSI Architecture Model- 4 standar d the targ et shall go to the BUS FREE ph ase following the successful rece ipt of the ABORT T ASK SET message.
Parallel SCSI Interface Product Manual, Rev. A 107 5.0 Miscellaneous SCSI bus characteristics Asynchronous conditions can o c cur on the SCSI bu s that ca use a SCSI device to pe rform certain actions that may alter the phase sequen ce of an I/O process.
108 Parallel SCSI Interface Product Manual, Rev. A A SCSI target port sh all respond to an atte ntion condition with MESSAGE OUT phase as follows: a. If an attention condition is cr eated during a COMMAND phase, t he target shall enter MESSAGE OUT phase af ter transferr ing par t or all of the command descr iptor block.
Parallel SCSI Interface Product Manual, Rev. A 109 The effect of the hard reset on tasks that have not completed, SCSI device reservations, and SCSI device operating modes is defined in the SCSI Archite cture Model-4 stand ard. Any SCSI device that dete cts a ha rd reset shall also set it s transfer agre ement to the default transfer a gree - ment.
110 Parallel SCSI Interface Product Manual, Rev. A • Active po inters (one set per initiator only). • Saved pointers (one or more set s per initiator , up to fifteen set s total). The use of these two types of pointer s is described in the following paragr aphs.
Parallel SCSI Interface Product Manual, Rev. A 111 5.6 Command processing considerations and e xception conditions 5.6.1 Command processing consid erations and exc eption conditions overview The follo.
112 Parallel SCSI Interface Product Manual, Rev. A A task manager that detect s an incorrect initiator connec tion shall abort all tasks for the initiator and the associ - ated logical unit and shall return CHECK CONDITION status for the task th at caused the incorrect initiator con - nection.
Parallel SCSI Interface Product Manual, Rev. A 113 6.0 SPI information unit s An information unit tran sfer transfers dat a in SPI informa tion units. The order in wh ich SPI information units are transferre d within an information un it transfer fo llows a prescribed sequence.
114 Parallel S CSI Interface Product Manual, Rev. A Logical recon nections occu r on the su ccessful target transmission and init iator receipt of a SPI L_Q informa - tion unit for an existing I/O process. The logical recon nection reest ablishes the I_T_L_Q nexus for that I/O pro - cess.
Parallel SCSI Interface Product Manual, Rev. A 115 [1] See T able 49 for the format of the SPI L_Q information unit. [2] See T able 46 for the format of the SPI Command info rmation unit.
116 Parallel S CSI Interface Product Manual, Rev. A [1] See T able 49 for the format of the SPI L_Q i n formation unit. [2] See T able 52 for the format of the SPI Dat a information unit.
Parallel SCSI Interface Product Manual, Rev. A 117 [1] See T able 49 for the format of the SPI L_Q information unit. [2] See T able 53 for the format of the SPI Dat a information unit.
118 Parallel S CSI Interface Product Manual, Rev. A [1] See T able 49 for the format of the SPI L_Q i n formation unit. [2] See T able 54 for the format of the SPI S tatus information unit. [3] See Figure 16 . Figure 18. SPI information unit sequence during status transfers 6.
Parallel SCSI Interface Product Manual, Rev. A 119 If the T ask Management Flags field is a supporte d value not equal to 00h , the t arget shall perfo rm the selected task mana gement function before processing any fur t her SPI information unit s regardless of the command type.
120 Parallel S CSI Interface Product Manual, Rev. A T a ble 47: T ask Attribute [2] The T ask Management Flags field is define d in T able 48 . If a T ask Management function fails, the T ask Manager shall te rminate the t ask wit h Good status. The p acketized failure code shall be set to T ask Man - agement Function Failed.
Parallel SCSI Interface Product Manual, Rev. A 121 Management Flags field is not zero. Any bytes between the end of a 6 byte CDB, 10 byte CDB, or 12 byte CDB and the end of the CDB field shall be reserved. [6] The Additiona l CDB field contains any CDB bytes beyo nd those cont ained within the standard 16 byte CDB field.
122 Parallel S CSI Interface Product Manual, Rev. A [1] The T ype field is defined in T able 50 . If a SCSI initiator port receives a type code that is not defin ed in Ta b l e 50 , that initiator shall follow the procedures defined in Section 3.5.2.2.
Parallel SCSI Interface Product Manual, Rev. A 123 T a ble 50: SPI L_ Q in formation unit type [2] T ag field is a 16-bit un signed integer assign ed by the ap plication client and sent to the initiator in the Send SCSI Command requ est. See Section 4.
124 Parallel S CSI Interface Product Manual, Rev. A than 509 would transfer 509 bytes of dat a plus 3 bytes of pad plus 4 bytes of iuCRC for a total tran sfer of 516 bytes).
Parallel SCSI Interface Product Manual, Rev. A 125 6.2.3 SPI dat a information unit The SPI data infor mation unit (see T able 52 ) contains dat a. The detection of a BUS FREE pha se following a SPI dat a information unit by a SCSI initiator port shall be equivalent to the initiator re ceiving a D ISCONNECT message.
126 Parallel S CSI Interface Product Manual, Rev. A tion unit the P_CRCA signal was asserted and a SCSI init iator port detect s a REQ transition after re ceiving the last iuCRC for a SPI data stream info rmation unit, that SCSI in itiator shall logically disconnect from the current I_T_L_Q nexus.
Parallel SCSI Interface Product Manual, Rev. A 127 6.2.5 SPI status information un it The SPI st atus information unit (see T able 54 ) contain s the completion status of the t ask indicated by the pre - ceding SPI L_Q info rmation unit.
128 Parallel S CSI Interface Product Manual, Rev. A Data List Length field and shall assume a length of zero. [4] If packetized failure data is p rovided, the Packetiz ed Failures V alid (RSPV ALID) bit shall be set to one and the Packetized Failures List Length fi eld shall specify the number of byte s in the Packetized Failures field.
Parallel SCSI Interface Product Manual, Rev. A 129 The iuCRC field shall use the algorith m define d in Subsection 1 1.3, ANSI SCSI Parallel Interface (SPI-5), T10/ 1525D.
130 Parallel S CSI Interface Product Manual, Rev. A.
Parallel SCSI Interface Product Manual, Rev. A 131 7.0 SCSI commands This section defines the SCSI comm and structure and describes a typical SCSI bus proce dure involving a command, status retu rn, and message interchange.
132 Parallel SCSI Interface Product Manual, Rev. A The Command Descriptor Block alw ays has an operat ion co de as the first byte of the command. This is fol - lowed by command p arameters (i f any), and a control field.
Parallel SCSI Interface Product Manual, Rev. A 133 7.2.1 Fixed and variable length Command Descript or Block format s For all commands, if the re is an invalid p arameter in the command descripto r block, the device server termi - nates the command without altering the medium.
134 Parallel SCSI Interface Product Manual, Rev. A T a ble 59: T ypical CDB fo r 12-byte commands See notes following T able 61 . T a ble 60: T ypical CDB fo r 16-byte commands Bit Byte 76543210 0 OPE.
Parallel SCSI Interface Product Manual, Rev. A 135 See notes following T able 61 . T a ble 61: T ypical variable length CDB Notes for T ables 57 , 58 , 59 , 60 , and 61 . [1] The Operation Code field of the Command Descripto r Block cont ains the code value indentifying the oper - ation being requ ested by the CDB.
136 Parallel SCSI Interface Product Manual, Rev. A 8.0 where the details of eac h command are describe d. [3] The Logical Block Address on logical units or within a p artition on device volumes shall begin with block zero and be contiguous up to the last logical blo ck on that logical un it or within that partition.
Parallel SCSI Interface Product Manual, Rev. A 137 T a ble 62: Co ntrol field [a] The Normal Auto Contingent Allegi ance (NACA) bit is used to control the rules for handling a n Auto Contingent Allegiance (ACA) conditio n caused by the comma nd. Section 7.
138 Parallel SCSI Interface Product Manual, Rev. A 7.3 St atus A S tatus byte shall be sent from the t arget to the init iator during the ST A TUS phase at the termination of each command as specified in T ables 63 and 64 unless the command is cleared by one of the following co nditions: 1.
Parallel SCSI Interface Product Manual, Rev. A 139 Busy . This status indi cates that the logical unit is busy . This status shall be return ed whenever a logical u nit is unable to accept a comma nd from an otherwise accept abl e initiator (i.e., no reservat ion conflicts).
140 Parallel SCSI Interface Product Manual, Rev. A 7.4 Command examples 7.4.1 Single command example A typical operation o n the SCSI bus i s likely to include a sin gle READ command to a peripheral device such as the drive. This oper ation is described in detail st arting with a request from the initiator .
Parallel SCSI Interface Product Manual, Rev. A 141 7.4.2 Disco nnect example In the single command example, the le ngth of time necessary to obt ain the data may require a time consuming physical seek.
142 Parallel SCSI Interface Product Manual, Rev. A 7.5 Timing e xamples T imes (T00 through T35) necessary to define performance ar e listed in the in dividual drive’ s Product Manual, in the “Disc drive SCSI timing” section. F or timing wavefo rms to define these times, refer to the SCSI Pa rallel Interface-5 specification (SPI-5 ).
Parallel SCSI Interface Product Manual, Rev. A 143 The handling of t a sks created by initiators other than t he faulted initiator depends on the va lue in the TST field in the Control mode page (see ANSI SCSI Primar y Commands-4, T1 0/1731-D).
144 Parallel SCSI Interface Product Manual, Rev. A Note. Some logical unit s may not detect an overl apped command until af ter the command descriptor block has been received . 7.6.3 Incorrect lo gical unit selection The target’ s response to an incorrect logical unit identifier is described in the following p a ragraphs.
Parallel SCSI Interface Product Manual, Rev. A 145 The control mode p a ge cont ains para meters affecting th e use of asynchronous event r eporting (see Seagate SCSI Command Refere nce Manual, Part numbe r 100293068) . Asynchronous Eve nt Reporting is used to signal a device that one of th e four events listed below has oc curred: a.
146 Parallel SCSI Interface Product Manual, Rev. A 7.6.6 Unit Attention condition The drive sets up the Unit Attention co ndition when it stores ( within itself) a Unit Attention condition flag for ea.
Parallel SCSI Interface Product Manual, Rev. A 147 7.6.7 T arge t hard reset a SCSI target port hard r e set is a SCSI target port re sponse to a SCSI target port Reset t ask management request (see SCSI Architecture Model-4, T1 0/1 157D), or a reset event within the service delivery subsystem.
148 Parallel SCSI Interface Product Manual, Rev. A The I T L nexus specifies th e relationship so that the drive can a lways reconnect to the initiator to restore the pointers for t ask as long as only one command per I T L nexus is issued. It is the res pons ibility of t he initiator to assure that only one command is issued at any time.
Parallel SCSI Interface Product Manual, Rev. A 149 The drive recove ry option, is to cont inue execution of commands in the q ueu e after the contingent allegiance condition has cleared. The drive retur ns Busy status to all other initiators while the continge nt allegiance condi - tion exists.
150 Parallel SCSI Interface Product Manual, Rev. A Since new operating definitions may pr eclude the execution of tasks that ar e already in prog ress, the target may disconnect to allo w completion of any tasks tha t ar e in progress.
Parallel SCSI Interface Product Manual, Rev. A 151 8.0 Drive features 8.1 S.M.A.R.T . system Some drive families me ntioned in Section 1.1 implement what is called in the industry the S.M.A.R.T . system. S.M.A.R.T . is an acronym for Self-Monitoring Analysis a nd Reporting T echnology .
152 Parallel SCSI Interface Product Manual, Rev. A The test s performed in the segme nts may be the same for the short and extended self-test s. The time required by a logical unit to complete it s ex.
Parallel SCSI Interface Product Manual, Rev. A 153 T able 65: Exception commands f or background self- test s a. Device types not listed in this t able do not have commands that are excep tions for background self- tests, other than th ose listed above for all device types.
154 Parallel SCSI Interface Product Manual, Rev. A T able 66: Self-test mode summary 8.3 Alternate error detection for the asynchronous information p hases (AIP)— Command, Message, and S tatus 8.
Parallel SCSI Interface Product Manual, Rev. A 155 8.3.2.1 Covere d signals Ta b l e 67 defines the signals to be co vered by th e protection code and th eir bit location s in the 21-bit code word. When a SCSI device receives an information byte , it also la tches the st ate of the othe r SCSI signals and values noted in T able 67 .
156 Parallel SCSI Interface Product Manual, Rev. A For each new run, the Sequence ID is set to zero for the first word transferred , set to on e for the second wor d transferred, set to two for the third word transferred, and set to thr ee for the fourth word transferred.
Parallel SCSI Interface Product Manual, Rev. A 157 8.3.2.2 Code des cription The protection code (see T able 68 ) is a cyclic bi nary BCH code . T able 68: Protection code The BCH protection code is a cyclic code with a generator polynomial of x 6 + x 5 + x 2 + 1.
158 Parallel SCSI Interface Product Manual, Rev. A 8.3.3.1 Protectio n code transmi ssion SCSI devices supporting this protec tion code transmit t he protection code check data during all Command, Message, and ST A TUS phases.
Parallel SCSI Interface Product Manual, Rev. A 159 8.4.2 Case 1—Power off during removal or insertion a. All SCSI devices are powered of f during physical reconfiguration. 8.4.3 Case 2—RST signal asserted continuously during removal or insert ion a.
160 Parallel SCSI Interface Product Manual, Rev. A c. A SCSI device being removed sh all maintain its power gr ound and logic grou nd prior to, during, and for at least 1 ms after the disconne ction of any device connector cont act from the SCSI bus. d.
Parallel SCSI Interface Product Manual, Rev. A 161 Index A abort message 138 abort task 138 abort task message 105 abort task set message 106 aborted command 4, 143 , 15 0 ACA.
162 Parallel SCSI Interface Product Manual, Rev. A code value reserved 131 command 4, 6 aborted 4 completed 5 ended 6 linked 7 overlapped 143 SCSI-3 standards 2 single, example 140 third party 11 unli.
Parallel SCSI Interface Product Manual, Rev. A 163 disconnect privile ge 148 domain 5, 9 dormant task state 5 double transition 6 DP-1 signals 34 drive select 17 driver 6 driver precom pensation 36 DT.
164 Parallel SCSI Interface Product Manual, Rev. A information unit seq uence 113 information unit transfer 6, 38 initial connection 6 initiator 3, 6, 14 , 131 , 140 faulted 6 multiple 3, 14 single 14 initiator connection incorrect 150 initiator dete cted error message 89 initiator port 13 input/outpu t SCSI bus signal 15 input/output.
Parallel SCSI Interface Product Manual, Rev. A 165 multidrop 7 multimode SCSI bus signal 15 multimode I/O circuits 15 multimode single-ended 7 multiple initiator 14 multiple initiators 3 multiple target 14 N NACA.
166 Parallel SCSI Interface Product Manual, Rev. A protection code er ror 158 protection code ge nerator 157 protection cod e transmission 158 protocol 8 layer 9 lower level 7 option 8 SCSI 9 SCSI-3 s.
Parallel SCSI Interface Product Manual, Rev. A 167 RSPVALID. see Packe tized Failures Valid RST. see Reset S save data pointer message 96 , 141 saved pointer 110 SCSI standards, scope of 2 SCSI applic.
168 Parallel SCSI Interface Product Manual, Rev. A SPI status information unit 113, 127 ST Data phase parallel tran sfers 38 ST DATA phas es 37 ST LVD phases 34 state of the bus 6 Status SPI status in.
Parallel SCSI Interface Product Manual, Rev. A 169 two-byte message 84 Type SPI L_Q information un it 121 , 122 U Ultra160 1 Ultra320 1 unconfirme d protocol service 11 unexpected bus free 138 unit at.
170 Parallel SCSI Interface Product Manual, Rev. A.
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Seagate T echnology LLC 920 Disc Drive, Scotts V alley , California 95066-4544, USA Publication Number: 1002930 69, Rev . A, Printed in USA.
An important point after buying a device Seagate Ultra 160 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
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