Page 3 - Parallel SCSI Interface
Page 4 - ©2006, Seagate Technology LLC All rights reserved
©2006, Seagate Technology LLC All rights reserved Publication number: 100293069, Rev. A March 2006 Seagate and Seagate Technology are registered trademarks of Seagate Technology LLC. SeaTools, SeaFONE, SeaBOARD, SeaTDD, and the Wave logo are either registered trade-marks or trademarks of Seagate Tec...
Page 5 - Revision status summary sheet; Revision
Parallel SCSI Interface Product Manual, Rev. A iii Revision status summary sheet Revision Date Writer/Engineer Sheets Affected Rev. A 03/27/06 C. Chalupa/G. Houlder All.
Page 7 - Parallel SCSI Interface Product Manual, Rev. A; Table of Contents
Parallel SCSI Interface Product Manual, Rev. A v Table of Contents 1.0 Interface requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 How to use this interface manual . . . . . . . . . . . . . . . . . . . . . . . ....
Page 13 - List of Figures
Parallel SCSI Interface Product Manual, Rev. A xi List of Figures Figure 1. SCSI client-server model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2. Voltage and current definitions . . . . . . . . . . . . . . . . . . . . . . . . ....
Page 15 - Interface requirements; How to use this interface manual; Unless required for clarity, “SCSI” is now used instead of “SCSI-3.”
Parallel SCSI Interface Product Manual, Rev. A 1 1.0 Interface requirements 1.1 How to use this interface manual This manual provides a description of the SCSI1 interface protocol and some general timing information as implemented by Seagate products. The features described in this manual are typica...
Page 16 - Scope of SCSI standards; Functional scope of SCSI
2 Parallel SCSI Interface Product Manual, Rev. A 1.1.1 Scope of SCSI standards Figure 1 uses a representative set of specifications to show the functional partitions and the relationships among SCSI standards applicable to drives covered by this manual. Figure 1. Functional scope of SCSI 1 standards...
Page 17 - Applicable standards; General interface description
Parallel SCSI Interface Product Manual, Rev. A 3 1.1.2 Applicable standards The following ANSI standards should be referenced for more details about SCSI system standards of opera-tion:• SCSI Architecture Model - 4 (SAM-4), T10/1683-D• SCSI Enclosure Services - 2 (SES-2), T10/1559-D• SCSI Block Comm...
Page 18 - SCSI client-server model
4 Parallel SCSI Interface Product Manual, Rev. A Figure 2. SCSI client-server model 1.2.1 Glossary aborted command —A SCSI command that has been ended by aborting the task created to execute it. ACA —Auto Contingent Allegiance (see below). additional sense code —a combination of the ADDITIONAL SENSE...
Page 19 - See
Parallel SCSI Interface Product Manual, Rev. A 5 command descriptor block —A structure used to communicate a command from an application client to a device server. Command structures of 6, 10, 12, or 16 bytes are used, but a new variable length command structure has recently been introduced. complet...
Page 26 - Message Name
12 Parallel SCSI Interface Product Manual, Rev. A 1.3 Physical interface characteristics The physical interface characteristics (cables, connectors, electrical descriptions, termination requirements, etc.) for the drives covered by this Interface Manual are found in each individual drive’s Product M...
Page 27 - Parallel SCSI Interface Product Manual, Rev. A ); SCSI bus
Parallel SCSI Interface Product Manual, Rev. A ) 13 2.0 SCSI bus This manual discusses only the “logical” and timing characteristics of the SCSI system and interface. A general description of the SCSI bus physical characteristics (voltages, connector configurations, pinouts, etc.) are given in the i...
Page 28 - SCSI IDs and associated SCSI bus arbitration priorities
14 Parallel SCSI Interface Product Manual, Rev. A ) The Host Adapter/Initiator must be identified by one of the 16 SCSI Device IDs (usually 7, which is highest arbi-tration priority). Make sure that none of the devices on the SCSI bus have duplicate IDs. Certain SCSI bus functions are assigned to th...
Page 29 - SCSI bus signals overview; Multimode—SE or LVD alternative
Parallel SCSI Interface Product Manual, Rev. A ) 15 2.1 SCSI bus signals overview Information transfer on the SCSI bus is allowed between only two SCSI devices at any given time except dur-ing MESSAGE IN PHASE when QAS is enabled. All SCSI devices that have QAS enabled are required to monitor messag...
Page 30 - P_CRC signal usage requirements; DT Data phase
16 Parallel SCSI Interface Product Manual, Rev. A ) During the SELECTION PHASE, RESELECTION PHASE, ST DATA PHASE, COMMAND PHASE, MESSAGE PHASE, and STATUS PHASE, this signal is referred to as DB(P_CRCA) and is sourced by the SCSI device port driving the Data Bus. The DB(P_CRCA) signal is associated ...
Page 31 - Drive select; Signal states; SE signals
Parallel SCSI Interface Product Manual, Rev. A ) 17 When information unit transfers are enabled, the P1 signal shall be continuously negated by the SCSI device driving the DB(15-0) signals and shall be ignored by the SCSI device receiving the DB(15-0) signals during DT DATA phases. During DT DATA ph...
Page 32 - DIFFERENTIAL B
18 Parallel SCSI Interface Product Manual, Rev. A ) Figure 3. Voltage and current definitions Figure 4 defines the signaling sense of the voltages appearing on the – signal and + signal lines as follows:a. The – signal terminal of the driver shall be negative with respect to the + signal terminal fo...
Page 33 - Signal sources; SCSI bus phase
Parallel SCSI Interface Product Manual, Rev. A ) 19 2.4 Signal sources Table 3 indicates the type of SCSI device allowed to source each signal. No attempt is made to show if the source is driving asserted, driving negated, or is released. All SCSI device drivers that are not active sources shall be ...
Page 34 - SCSI bus timing; SCSI bus control timing values in nanoseconds; This is a recommended time. It is not mandatory.
20 Parallel SCSI Interface Product Manual, Rev. A ) 2.5 SCSI bus timing Unless otherwise indicated, the delay time measurements for each SCSI device, defined in paragraphs 2.5.1through 2.5.60 shall be calculated from signal conditions existing at that SCSI device’s own SCSI bus connec-tion. Thus, th...
Page 35 - SCSI bus data and information phase ST timing values
Parallel SCSI Interface Product Manual, Rev. A ) 21 Table 5: SCSI bus data and information phase ST timing values [1] SCSI bus timing values specified by the maximum transfer rate for the given range shall apply even if a slower transfer rate within the given range is negotiated. [2] Cable skew is m...
Page 37 - Transmit SCSI bus data and information phase DT timing values; Timing description
Parallel SCSI Interface Product Manual, Rev. A ) 23 Table 7: Transmit SCSI bus data and information phase DT timing values [1] SCSI bus timing values specified by the maximum transfer rate for the given range shall apply even if a slower transfer rate within the given range is negotiated. [2] See Se...
Page 38 - Receive SCSI bus data and information phase DT timing values; Calculated assuming timing budget shown in Table 9.
24 Parallel SCSI Interface Product Manual, Rev. A ) Table 8: Receive SCSI bus data and information phase DT timing values [1] SCSI bus timing values specified by the maximum transfer rate for the given range shall apply even if a slower transfer rate within the given range is negotiated. [2] See Sec...
Page 40 - Arbitration delay; Item; from table 6; Transmitter and receiver errors:; Cable skew; Crosstalk time shift; Time impact; ISI of data; Worse case pattern; Total interconnect budget
26 Parallel SCSI Interface Product Manual, Rev. A ) 2.5.1 Arbitration delay The minimum time a SCSI device shall wait from asserting BSY for arbitration until the data bus can be exam-ined to see if arbitration has been won (see Section 3.1.2). There is no maximum time. 2.5.2 ATN transmit setup time...
Page 47 - Measurement points
Parallel SCSI Interface Product Manual, Rev. A ) 33 The minimum time that a SCSI target port shall negate the REQ signal while using synchronous transfers or paced transfers, provided it is not transitioning P_CRCA during data group transfers. Also, the minimum time that a SCSI initiator port shall ...
Page 48 - LVD measurement points; Clocking methods for data transfers
34 Parallel SCSI Interface Product Manual, Rev. A ) SE SCSI devices with data transfer rates up to and including Fast-20 shall use the measurement points defined in Section 9 of ANSI standard SPI-4, for the measurement of the timing values. The rise and fall times for the SE REQ/ACK signals shall be...
Page 50 - Paced transfer on a SCSI bus; transfer period = 25 ns
36 Parallel SCSI Interface Product Manual, Rev. A ) Figure 7. DT synchronous transfer example Figure 8. Paced transfer example 2.8 Paced transfer on a SCSI bus A SCSI bus that supports paced transfers has additional driver and receiver functions required over those used with synchronous transfers or...
Page 51 - Data transfer modes; Asynchronous transfers; SCSI device ports default to 8-bit asynchronous transfers.; Synchronous transfers; Optional
Parallel SCSI Interface Product Manual, Rev. A ) 37 The receiver skew compensation and clock shifting adjust the timing relationship between the clocking signal (i.e., REQ or ACK) and the signals being clocked (e.g., the data bus signals). That adjustment causes the clock signal to align with the mi...
Page 52 - ST DATA phase parallel transfers; Data group transfers; The value of the pad bytes within the pad field is vendor specific.; Information unit transfers; The value of the pad bytes is vendor-specific.
38 Parallel SCSI Interface Product Manual, Rev. A ) 2.10 ST DATA phase parallel transfers The format of data transmitted during ST DATA phases consists of data and protection. Parity generation and checking give some error detection protection in the ST phase data. 2.11 DT DATA phase parallel transf...
Page 53 - Negotiation; Negotiation algorithm
Parallel SCSI Interface Product Manual, Rev. A ) 39 The iuCRC shall be used to protect all SPI information units. The SCSI device that originates the SPI informa-tion unit sends the necessary pad bytes and iuCRC fields. An iuCRC interval may also be specified. The iuCRC interval specifies the number...
Page 54 - When to negotiate; Field name
40 Parallel SCSI Interface Product Manual, Rev. A ) If the responding negotiation message contains values the originating port does not support, the originating port shall respond with a MESSAGE REJECT message. 2.12.2 When to negotiate Each port shall maintain a negotiation required flag for each ot...
Page 55 - Responding message requirements
Parallel SCSI Interface Product Manual, Rev. A ) 41 When negotiating, the responding port shall respond with values that are a subset of the values in the originat-ing message as indicated in Table 12 (e.g., if the originating message requests a REQ/ACK offset of 10h, the responding message has a RE...
Page 56 - Transfer agreements
42 Parallel SCSI Interface Product Manual, Rev. A ) 2.12.4 Transfer agreements The transfer agreements that are in effect for various combinations of field values are described in Table 13. Table 13: Transfer agreements Transfer agreement REQ/ACK offset Transfer period factor Transfer width exponent...
Page 57 - Table abbreviations are defined as follows:; Transfer period factor
Parallel SCSI Interface Product Manual, Rev. A ) 43 2.12.5 Transfer period factor The Transfer Period Factor field selects the transfer period and determines which transfer rate’s timing values in Tables 5, 6, 7, and 8 shall be honored, provided that REQ/ACK OFFSET is greater than 00h. The field val...
Page 58 - Value; Value; Obsolete
44 Parallel SCSI Interface Product Manual, Rev. A ) 2.12.6 REQ/ACK offset The REQ/ACK OFFSET field determines the maximum number of REQs allowed to be outstanding before a corresponding ACK is received at the SCSI target port during synchronous or paced transfers. For ST synchro-nous transfers the R...
Page 59 - Protocol options; Table 18 lists the protocol options bits.; Protocol options bits; Name
Parallel SCSI Interface Product Manual, Rev. A ) 45 2.12.8 Protocol options The protocol options fields affect the protocol used between the ports. The SCSI target port uses the protocol options bits to indicate to the SCSI initiator port if it agrees to enable the requested protocol options. Except...
Page 60 - Bus phases resulting from IU_REQ changes; or BUS FREE phase; a. PPR negotiation keeping IU_REQ set to one; BUS FREE phase
46 Parallel SCSI Interface Product Manual, Rev. A ) Table 19 describes the bus phases resulting from IU_REQ changes. 2.12.8.2 DT_REQ The SCSI initiator port shall set DT_REQ to one to request that DT DATA phases be enabled. In response, the SCSI target port shall set DT_REQ to one if it agrees to us...
Page 62 - Negotiable field combinations
48 Parallel SCSI Interface Product Manual, Rev. A ) 2.12.9 Negotiable field combinations Not all combinations of the negotiable fields are valid. Only the combinations defined in Table 20 shall be allowed. All other combinations of the listed fields are reserved. Table 20: Valid negotiable field com...
Page 63 - Message restrictions
Parallel SCSI Interface Product Manual, Rev. A ) 49 2.12.10 Message restrictions PPR may be originated by SCSI initiator ports but shall not be originated by SCSI target ports. If bus expanders are present, SCSI initiator ports should only use PPR when requesting values not attainable via WDTR and S...
Page 65 - Logical characteristics; SCSI bus phases overview; The drive responds to the following phases:
Parallel SCSI Interface Product Manual, Rev. A 51 3.0 Logical characteristics The operations of the SCSI bus as described in this section are supported by the drive as specified in each individual drive’s Product Manual. The drive always functions as the target unless otherwise stated. 3.1 SCSI bus ...
Page 66 - Expected bus free phases
52 Parallel SCSI Interface Product Manual, Rev. A a. after any bus reset event.b. after a transceiver mode change reset event.c. after an Abort Task management function is successfully received by a SCSI target port;d. after an Abort Task Set management function is successfully received by a SCSI ta...
Page 67 - Normal ARBITRATION phase; examine the Data Bus.
Parallel SCSI Interface Product Manual, Rev. A 53 SCSI devices with arbitration fairness enabled shall maintain a fairness register that records the SCSI IDs of devices that need a chance to arbitrate (see Section 3.4). Fairness in normal arbitration is enabled in targets by the Disconnect-Reconnect...
Page 68 - QAS protocol; to enter selection phase; QAS phase overview; then wait for ACK to be true.
54 Parallel SCSI Interface Product Manual, Rev. A 3.1.2.2 QAS protocol Quick Arbitration and Selection (QAS) allows a SCSI target port with an information unit transfer agreement in effect and QAS enabled (see Section 4.3.12) that is currently connected to a SCSI initiator port that has infor-mation...
Page 69 - SELECTION phase
Parallel SCSI Interface Product Manual, Rev. A 55 4. If the SCSI initiator creates an attention condition, the SCSI target port shall go to a MESSAGE OUT phase, receive all the message bytes, and cause an unexpected bus free by generating a BUS FREE phase (see Section 3.1.1.1 on page 51). 5. If the ...
Page 70 - Selection overview
56 Parallel SCSI Interface Product Manual, Rev. A Refer to Section 3.4 for a description of the fairness algorithm which applies during SELECTION and RESE-LECTION phases. 3.2.1 Selection overview The SCSI device that won a normal arbitration has both the BSY and SEL signals asserted and has delayed ...
Page 71 - Selection using attention condition timeout procedure
Parallel SCSI Interface Product Manual, Rev. A 57 3.2.1.1.4 Selection using attention condition timeout procedure Two optional selection timeout procedures are specified for clearing the SCSI bus if the initiator waits a mini-mum of one selection timeout delay and there has been no BSY signal respon...
Page 72 - RESELECTION phase; RESELECTION phase overview
58 Parallel SCSI Interface Product Manual, Rev. A (a) Optionally, the initiator shall assert the RST signal (see Section 5.3); (b) Optionally, the initiator shall continue asserting the SEL signal and shall release the Data Bus, DB(P_CRCA), or DB(P1). If the initiator has not detected the BSY signal...
Page 73 - Physical reconnection timeout procedure; SCSI bus fairness
Parallel SCSI Interface Product Manual, Rev. A 59 glitch may cause the BSY signal to appear false for up to a round-trip propagation delay following the release of the BSY signal by the initiator. This is the reason why the BUS FREE phase is recognized only after both the BSY and SEL signals are con...
Page 74 - Information transfer phases; Signal
60 Parallel SCSI Interface Product Manual, Rev. A 3.5 Information transfer phases The COMMAND, DATA, STATUS, and MESSAGE phases are grouped together as information transfer phases because they are all used to transfer data or control information via the data bus. The actual contents of the informati...
Page 75 - Asynchronous transfer
Parallel SCSI Interface Product Manual, Rev. A 61 Synchronous transfers shall only be used for negotiated transfer rates less than or equal to Fast-80. Paced transfers shall only be used for a negotiated transfer rate of Fast-160. 3.5.1 Asynchronous transfer The target shall control the direction of...
Page 76 - DT synchronous transfer; and
62 Parallel SCSI Interface Product Manual, Rev. A hold time after the assertion of the REQ signal. The target shall assert the REQ signal for a minimum of one transmit assertion period. The target may then negate the REQ signal and change or release the DB(7-0,P_CRCA) or DB(15-0,P_CRCA,P1) signals. ...
Page 78 - Data group data field transfer; P_CRCA signal for a minimum of a pCRC transmit hold time
64 Parallel SCSI Interface Product Manual, Rev. A ABORT TASK message (see Section 4.5.2) to the target. The target shall send a SPI L_Q/SPI status informa-tion unit pair to the initiator with a CHECK CONDITION status and a sense key set to Aborted Command for the task associated with the received AB...
Page 80 - Data group pad field and pCRC field transfer to SCSI target port
66 Parallel SCSI Interface Product Manual, Rev. A Note. The above requirements in steps 6), 10), and 14) to not wait for the ACK transition corresponding to the previous REQ transition were not present in the SPI-3 standard. For compatibility with old designs SCSI initiator ports should generate ACK...
Page 82 - Paced transfer
68 Parallel SCSI Interface Product Manual, Rev. A The target shall read the value of the DB(15-0) signals within one receive hold time of the transition of the ACK signal. The initiator shall use the pad bytes, if any, in the generation of the transmitted pCRC. The target shall then use those pad by...
Page 83 - DT DATA IN phase training pattern
Parallel SCSI Interface Product Manual, Rev. A 69 If the retain training information is enabled, a training pattern shall be transferred at the start of the first DT DATA phase for each data transfer direction after the retain training information is enabled. The SCSI device shall save training conf...
Page 84 - Start of section C
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., simultaneously repeat a 1100b bit pattern 12 times on each signal) while asserting and negating REQ at the negotiated transfer period ...
Page 85 - P1 data valid/invalid state transitions
Parallel SCSI Interface Product Manual, Rev. A 71 The SCSI initiator port shall begin the section A of its training pattern independent of the start of the SCSI tar-get ports training pattern if it detects the SEL and MSG true, and C/D and I/O false on the first assertion of the REQ signal. The SCSI...
Page 86 - Starting pacing transfers at end of training pattern; X X X X X X O O O O O O O O O O X X X X X X X X X X X X O O O O O O X X X X O O O O O O; X X X X X X O O O O O O O O O O X X X X O O X X X X X X O O O O O O X X X X O O O O O O
72 Parallel SCSI Interface Product Manual, Rev. A The data invalid state shall have at least one transition of P1 before changing states. The minimum data invalid time is four transfer periods. This ensures a maximum run length of three cycles for P1. The data invalid state shall last an even number...
Page 87 - Ending pacing transfers
Parallel SCSI Interface Product Manual, Rev. A 73 The SCSI target port shall begin pacing transfers only after meeting all the following:• signal restrictions between information transfer phases listed in Section 3.10;• the signal restrictions between a RESELECTION phase and a DT DATA IN phase liste...
Page 88 - Deskewing; All SCSI devices shall support 8-bit narrow data transfers.
74 Parallel SCSI Interface Product Manual, Rev. A and (e) shall hold the DB(15-0) signals valid for a minimum of one transmit hold time. If the I/O signal is false (i.e., transfer to the SCSI target port), to receive SPI information units the SCSI target port: (a) shall read the value of the DB(15-0...
Page 89 - Wide SCSI byte order; COMMAND phase; COMMAND phase description; DATA phase; DATA phase overview
Parallel SCSI Interface Product Manual, Rev. A 75 Table 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 transfer, then the values of the remaining higher-numbered bits are undefined. However, when using parity protection, the ...
Page 90 - STATUS phase
76 Parallel SCSI Interface Product Manual, Rev. A 3.7.3 DT DATA OUT phase The DT DATA OUT phase allows the SCSI target port to request that data be sent from the SCSI initiator device to the SCSI target device using DT data transfers. The target shall assert the MSG signal and negate the C/D and I/O...
Page 91 - MESSAGE IN phase exception condition handling; code to Message Error or; Signal restrictions between phases
Parallel SCSI Interface Product Manual, Rev. A 77 A QAS-capable SCSI initiator port shall assert ACK for a minimum of one QAS non-data phase REQ(ACK) period. 3.9.2.1 MESSAGE IN phase exception condition handling If the SCSI initiator port detects a parity error on any message byte it receives, the S...
Page 92 - SCSI bus phase sequences; SCSI bus phase sequences overview
78 Parallel SCSI Interface Product Manual, Rev. A d. When switching the Data Bus or DB(P_CRCA) signal direction from out (SCSI initiator port driving) to in (SCSI target port driving), the target shall delay driving the Data Bus, DB(P_CRCA), and/or DB(P1) by at least one data release delay plus one ...
Page 95 - Data bus protection; Data bus protection overview; Action
Parallel SCSI Interface Product Manual, Rev. A 81 3.11.5 Phase sequences for physical selection using attention condition with information unit transfers enabled The sequences for a selection with attention condition while an information unit transfer agreement is in effect shall be as shown in Figu...
Page 96 - DT data bus protection using CRC
82 Parallel SCSI Interface Product Manual, Rev. A For COMMAND, MESSAGE, and STATUS phases, the DB(P_CRCA) signal shall indicate odd parity for DB(7-0). The DB(P1) signal shall not be checked. For ST DATA phases, the DB(P_CRCA) signal shall indicate odd parity for DB(7-0). If 8-bit transfers are enab...
Page 97 - Message system specification; General message protocols and formats
Parallel SCSI Interface Product Manual, Rev. A 83 4.0 Message system specification SCSI protocol messages allow communication between a SCSI initiator port and a SCSI target port for the pur-pose of link management. The link management messages used for this purpose are defined within this stan-dard...
Page 98 - Message format; The EXTENDED MESSAGE LENGTH field
84 Parallel SCSI Interface Product Manual, Rev. A Table 24: Message format 4.2.1 One-byte messages One-byte messages consist of a single byte transferred during a MESSAGE phase. The byte’s message code determines the message to be performed as defined in Tables 27, 40, and 45. The IDENTIFY message i...
Page 99 - Extended Message Codes; in Paragraphs referenced in Table 27.; Message categories; LINK CONTROL MESSAGES
Parallel SCSI Interface Product Manual, Rev. A 85 Table 26: Extended Message Codes 1. The EXTENDED MESSAGE ARGUMENTS are specified within the Extended Message Descriptions in Paragraphs referenced in Table 27. 4.3 Message categories The messages supported by the various drives are divided up into ca...
Page 101 - DISCONNECT; current task may be completed.; IDENTIFY
Parallel SCSI Interface Product Manual, Rev. A 87 4.3.2 DISCONNECT The DISCONNECT message is sent from a SCSI target port to inform an initiator that the target 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 comp...
Page 102 - IGNORE WIDE RESIDUE; The NUMBER OF BYTES TO IGNORE; Ignore field definition; Bit; Reserved
88 Parallel SCSI Interface Product Manual, Rev. A Only one logical unit number shall be identified per task. The initiator may send one or more IDENTIFY mes-sages during a task. A second IDENTIFY message with a different value in the LUN field shall not be issued before a BUS FREE phase; if a target...
Page 103 - INITIATOR DETECTED ERROR
Parallel SCSI Interface Product Manual, Rev. A 89 4.3.5 INITIATOR DETECTED ERROR The INITIATOR DETECTED ERROR message is sent from an initiator to inform a target that an error has occurred that does not preclude the target from retrying the task. The source of the error may either be related to pre...
Page 104 - MODIFY DATA POINTER message format; ARGUMENT
90 Parallel SCSI Interface Product Manual, Rev. A It is recommended that the target not attempt to move the data pointer outside the range addressed by the command. Initiators may or may not place further restrictions on the acceptable values. Should the target send an Argument value that is not sup...
Page 105 - MODIFY BIDIRECTIONAL DATA POINTER message format
Parallel SCSI Interface Product Manual, Rev. A 91 Table 32: MODIFY BIDIRECTIONAL DATA POINTER message format 4.3.11 NO OPERATION The NO OPERATION message is sent from an initiator in response to a target’s request for a message when the initiator does not currently have any other valid message to se...
Page 106 - PARALLEL PROTOCOL REQUEST; Transfer period equals the period factor x 4.; Fast-5 data is latched using a transfer period of less than; TRANSFER PERIOD FACTOR
92 Parallel SCSI Interface Product Manual, Rev. A 4.3.12 PARALLEL PROTOCOL REQUEST PARALLEL PROTOCOL REQUEST messages (see Table 33) are used to negotiate a synchronous data trans-fer agreement, a wide data transfer agreement, and set the protocol options between two SCSI devices. Table 33: PARALLEL...
Page 107 - Asynch; FFh; Synchronous or paced transfers with unlimited offset.
Parallel SCSI Interface Product Manual, Rev. A 93 See Section 3.5 for an explanation of the differences between ST and DT data transfers. The REQ/ACK OFFSET value is chosen to prevent overflow conditions in the port’s receive buffer and offset counter. The REQ/ACK OFFSET values and which timing valu...
Page 108 - Valid protocol options bit combinations; Description; Use ST DATA IN and ST DATA OUT phases to transfer data
94 Parallel SCSI Interface Product Manual, Rev. A Table 34: Valid protocol options bit combinations A Parallel Protocol Request agreement applies to all logical units of the two SCSI devices that negotiated agreement. That is, if SCSI device A, acting as an initiator, negotiates a data transfer agre...
Page 109 - Target’s Parallel Protocol
Parallel SCSI Interface Product Manual, Rev. A 95 be changed. Each SCSI device when transmitting data shall respect the negotiated limits set by the other's PARALLEL PROTOCOL REQUEST message, but it is permitted to transfer data with larger periods, smaller synchronous REQ/ACK offsets, or both. The ...
Page 110 - QAS REQUEST
96 Parallel SCSI Interface Product Manual, Rev. A If an abnormal condition prevents the target from responding with a PARALLEL PROTOCOL REQUEST mes-sage or with a MESSAGE REJECT message, then both SCSI devices shall use the eight-bit/asynchronous data transfer mode with all the protocol options bits...
Page 111 - SYNCHRONOUS DATA TRANSFER REQUEST; The TRANSFER PERIOD FACTOR field values are defined below.
Parallel SCSI Interface Product Manual, Rev. A 97 4.3.16 SYNCHRONOUS DATA TRANSFER REQUEST Synchronous Data Transfer Request (SDTR) messages (see Table 36) are used to negotiate a synchronous data transfer agreement between two SCSI devices. Table 36: Synchronous Data Transfer Request message format...
Page 112 - SDTR messages implied agreements; Implied agreement
98 Parallel SCSI Interface Product Manual, Rev. A a. after a HARD RESET;b. after a TARGET RESET message;c. after a power cycle; andd. after a change in the transceiver mode (e.g., LVD mode to MSE mode). Any condition that leaves the data transfer agreement in an indeterminate state shall cause the S...
Page 113 - Target initiated SDTR negotiation
Parallel SCSI Interface Product Manual, Rev. A 99 4.3.16.1 Target initiated SDTR negotiation If the target recognizes that SDTR negotiation is required, it sends an SDTR message to the initiator. The initi-ator shall create an attention condition on the last byte of the SDTR message from the target,...
Page 114 - WIDE DATA TRANSFER REQUEST; TRANSFER WIDTH EXPONENT
100 Parallel SCSI Interface Product Manual, Rev. A 4.3.18 WIDE DATA TRANSFER REQUEST WIDE DATA TRANSFER REQUEST (WDTR) messages (see Table 38) are used to negotiate a wide data transfer agreement between two SCSI devices. Table 38: WIDE DATA TRANSFER REQUEST message format The TRANSFER WIDTH EXPONEN...
Page 115 - WDTR message implied agreement; the target shall switch to a
Parallel SCSI Interface Product Manual, Rev. A 101 fer agreement shall remain intact; b. If a WDTR message fails for any other reason, the prior synchronous data transfer agreement shall remain intact; or c. If a WDTR message is not rejected with a MESSAGE REJECT message, a WDTR message shall reset ...
Page 116 - Task attribute messages; field is an 8-bit unsigned integer; Task attribute message overview and codes
102 Parallel SCSI Interface Product Manual, Rev. A get causing an unexpected bus free. The initiator shall accept such action as aborting the WDTR negotiation, and both SCSI devices shall go to eight-bit data transfer mode for data transfers between the two SCSI devices. Any prior synchronous data t...
Page 117 - Out
Parallel SCSI Interface Product Manual, Rev. A 103 When a target does a physical reconnection to an initiator to continue a tagged task, the Simple Queue mes-sage shall be sent following the Identify message to resume the I_T_L_Q nexus for the task. Only one I_T_L_Q nexus may occur during a physical...
Page 119 - Task management messages; Task management message codes
Parallel SCSI Interface Product Manual, Rev. A 105 4.5 Task management messages Table 45 lists the codes used for messages that manage tasks. Details about these task management mes-sages is given in subsections following the table. 4.5.1 Task management message codes Table 45: Task management messa...
Page 120 - ABORT TASK SET
106 Parallel SCSI Interface Product Manual, Rev. A 4.5.3 ABORT TASK SET The ABORT TASK SET message is defined in the SCSI Architecture Model-4 standard. In addition to the requirements in the SCSI Architecture Model-4 standard the target shall go to the BUS FREE phase following the successful receip...
Page 121 - Miscellaneous SCSI bus characteristics; Attention condition
Parallel SCSI Interface Product Manual, Rev. A 107 5.0 Miscellaneous SCSI bus characteristics Asynchronous conditions can occur on the SCSI bus that cause a SCSI device to perform certain actions that may alter the phase sequence of an I/O process. Furthermore, SCSI devices may not all be powered on...
Page 122 - Bus reset condition
108 Parallel SCSI Interface Product Manual, Rev. A A SCSI target port shall respond to an attention condition with MESSAGE OUT phase as follows: a. If an attention condition is created during a COMMAND phase, the target shall enter MESSAGE OUT phase after transferring part or all of the command desc...
Page 123 - Reset events; Bus reset event; Asynchronous condition recovery; SCSI pointers; Of these three-pointer sets there are two types:
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 Architecture Model-4 standard. Any SCSI device that detects a hard reset shall also set its transfer agre...
Page 124 - Active pointers
110 Parallel SCSI Interface Product Manual, Rev. A • Active pointers (one set per initiator only).• Saved pointers (one or more sets per initiator, up to fifteen sets total). The use of these two types of pointers is described in the following paragraphs. 5.5.2 Active pointers Active pointers repres...
Page 125 - Command processing considerations and exception conditions; Asynchronous event notification
Parallel SCSI Interface Product Manual, Rev. A 111 5.6 Command processing considerations and exception conditions 5.6.1 Command processing considerations and exception conditions overview The following subclauses describe some aspects of command processing, including exception conditions and error h...
Page 126 - Unexpected RESELECTION phase
112 Parallel SCSI Interface Product Manual, Rev. A A task manager that detects an incorrect initiator connection shall abort all tasks for the initiator and the associ-ated logical unit and shall return CHECK CONDITION status for the task that caused the incorrect initiator con-nection. The sense ke...
Page 127 - SPI information units; Information unit transfer logical operations
Parallel SCSI Interface Product Manual, Rev. A 113 6.0 SPI information units An information unit transfer transfers data in SPI information units. The order in which SPI information units are transferred within an information unit transfer follows a prescribed sequence. When information unit transfe...
Page 129 - or
Parallel SCSI Interface Product Manual, Rev. A 115 [1] See Table 49 for the format of the SPI L_Q information unit.[2] See Table 46 for the format of the SPI Command information unit.[3] See Figure 16.[4] See Figure 18. Figure 15. SPI information unit sequence during initial connection SPI L_Q (alwa...
Page 130 - Attention
116 Parallel SCSI Interface Product Manual, Rev. A [1] See Table 49 for the format of the SPI L_Q information unit.[2] See Table 52 for the format of the SPI Data information unit.[3] See Figure 18. Figure 16. SPI information unit sequence during data type transfers SPI L_Q (always Targ to Init) (lo...
Page 132 - SPI command information unit
118 Parallel SCSI Interface Product Manual, Rev. A [1] See Table 49 for the format of the SPI L_Q information unit.[2] See Table 54 for the format of the SPI Status information unit.[3] See Figure 16. Figure 18. SPI information unit sequence during status transfers 6.2 SPI information units 6.2.1 SP...
Page 134 - Indicates no task management requests for the current task.
120 Parallel SCSI Interface Product Manual, Rev. A Table 47: Task Attribute [2] The Task Management Flags field is defined in Table 48. If a Task Management function fails, the Task Manager shall terminate the task with Good status. The packetized failure code shall be set to Task Man-agement Functi...
Page 135 - SPI L_Q information unit
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 Additional CDB field contains any CDB bytes beyond those contained within the standard...
Page 139 - SPI data information unit; SPI data stream information unit; The SPI data stream information unit (see Table 53) contains data.; MSB
Parallel SCSI Interface Product Manual, Rev. A 125 6.2.3 SPI data information unit The SPI data information unit (see Table 52) contains data. The detection of a BUS FREE phase following a SPI data information unit by a SCSI initiator port shall be equivalent to the initiator receiving a DISCONNECT ...
Page 141 - SPI status information unit; If a task completes with a Good status, a SNSVALID
Parallel SCSI Interface Product Manual, Rev. A 127 6.2.5 SPI status information unit The SPI status information unit (see Table 54) contains the completion status of the task indicated by the pre-ceding SPI L_Q information unit. The target shall consider the SPI status information unit transmission ...
Page 145 - SCSI commands; Command implementation requirements
Parallel SCSI Interface Product Manual, Rev. A 131 7.0 SCSI commands This section defines the SCSI command structure and describes a typical SCSI bus procedure involving a command, status return, and message interchange. The command structure defined herein provides for a contiguous set of logical b...
Page 147 - Fixed and variable length Command Descriptor Block formats; See notes following Table 61.
Parallel SCSI Interface Product Manual, Rev. A 133 7.2.1 Fixed and variable length Command Descriptor Block formats For all commands, if there is an invalid parameter in the command descriptor block, the device server termi-nates the command without altering the medium. Table 57 shows the typical fo...
Page 152 - Status; A description of the status byte codes is given below.
138 Parallel SCSI Interface Product Manual, Rev. A 7.3 Status A Status byte shall be sent from the target to the initiator during the STATUS phase at the termination of each command as specified in Tables 63 and 64 unless the command is cleared by one of the following conditions:1. an Abort message2...
Page 153 - Intermediate–Condition Met.; mode page TAS bit is set to one.; Status precedence
Parallel SCSI Interface Product Manual, Rev. A 139 Busy. This status indicates that the logical unit is busy. This status shall be returned whenever a logical unit is unable to accept a command from an otherwise acceptable initiator (i.e., no reservation conflicts). The recom-mended initiator recove...
Page 154 - Command examples; Single command example; Figure 19. Single command example
140 Parallel SCSI Interface Product Manual, Rev. A 7.4 Command examples 7.4.1 Single command example A typical operation on the SCSI bus is likely to include a single READ command to a peripheral device such as the drive. This operation is described in detail starting with a request from the initiat...
Page 155 - Disconnect example; Figure 20. Disconnect example
Parallel SCSI Interface Product Manual, Rev. A 141 7.4.2 Disconnect example In the single command example, the length of time necessary to obtain the data may require a time consuming physical seek. In order to improve system throughput, the drive may disconnect from the initiator, freeing the SCSI ...
Page 156 - Timing examples; Auto Contingent Allegiance or Contingent Allegiance
142 Parallel SCSI Interface Product Manual, Rev. A 7.5 Timing examples Times (T00 through T35) necessary to define performance are listed in the individual drive’s Product Manual, in the “Disc drive SCSI timing” section. For timing waveforms to define these times, refer to the SCSI Parallel Interfac...
Page 157 - Clearing an Auto Contingent Allegiance condition
Parallel SCSI Interface Product Manual, Rev. A 143 The handling of tasks created by initiators other than the faulted initiator depends on the value in the TST field in the Control mode page (see ANSI SCSI Primary Commands-4, T10/1731-D). If TST=000b, tasks created by other initiators while the ACA ...
Page 158 - Incorrect logical unit selection; The logical unit identifier may be incorrect because:; Sense data; The following clauses describe the last two transfer methods.; Asynchronous Event Reporting
144 Parallel SCSI Interface Product Manual, Rev. A Note. Some logical units may not detect an overlapped command until after the command descriptor block has been received. 7.6.3 Incorrect logical unit selection The target’s response to an incorrect logical unit identifier is described in the follow...
Page 159 - Autosense
Parallel SCSI Interface Product Manual, Rev. A 145 The control mode page contains parameters affecting the use of asynchronous event reporting (see Seagate SCSI Command Reference Manual, Part number 100293068). Asynchronous Event Reporting is used to signal a device that one of the four events liste...
Page 160 - Unit Attention condition; could affect one or more of the other initiators).
146 Parallel SCSI Interface Product Manual, Rev. A 7.6.6 Unit Attention condition The drive sets up the Unit Attention condition when it stores (within itself) a Unit Attention condition flag for each device on the SCSI bus having a SCSI initiator port relationship with the drive, and this Unit Atte...
Page 161 - Target hard reset; To execute a logical unit reset the logical unit shall:; Untagged task queuing
Parallel SCSI Interface Product Manual, Rev. A 147 7.6.7 Target hard reset a SCSI target port hard reset is a SCSI target port response to a SCSI target port Reset task management request (see SCSI Architecture Model-4, T10/1157D), or a reset event within the service delivery subsystem. The definiti...
Page 162 - Tagged task queuing
148 Parallel SCSI Interface Product Manual, Rev. A The I T L nexus specifies the relationship so that the drive can always reconnect to the initiator to restore the pointers for task as long as only one command per I T L nexus is issued. It is the responsibility of the initiator to assure that only ...
Page 163 - Parameter rounding
Parallel SCSI Interface Product Manual, Rev. A 149 The drive recovery option, is to continue execution of commands in the queue after the contingent allegiance condition has cleared. The drive returns Busy status to all other initiators while the contingent allegiance condi-tion exists. During this ...
Page 164 - Incorrect initiator connection; An incorrect initiator connection occurs on a reconnection if:
150 Parallel SCSI Interface Product Manual, Rev. A Since new operating definitions may preclude the execution of tasks that are already in progress, the target may disconnect to allow completion of any tasks that are in progress. Operating definition changes that may cause conflicts with the normal ...
Page 165 - Drive features; The short and extended self-tests; The following are examples of segments:
Parallel SCSI Interface Product Manual, Rev. A 151 8.0 Drive features 8.1 S.M.A.R.T. system Some drive families mentioned 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 and Reporting Technology. The intent of the S...
Page 166 - Foreground mode; field in the log page. The Self-Test Results field shall be set to
152 Parallel SCSI Interface Product Manual, Rev. A The tests performed in the segments may be the same for the short and extended self-tests. The time required by a logical unit to complete its extended self-test is reported in the Extended Self-Test Completion Time field in the Control mode page (s...
Page 167 - Exception commands for background self-tests; tests, other than those listed above for all device types.; Elements common to foreground and background self-test modes; Command; WRITE BUFFER (with the mode set to any download microcode option; Direct access; FORMAT UNIT
Parallel SCSI Interface Product Manual, Rev. A 153 Table 65: Exception commands for background self-tests a. Device types not listed in this table do not have commands that are exceptions for background self- tests, other than those listed above for all device types. b. See Seagate SCSI Command Refe...
Page 168 - Self-test mode summary; Foreground After the
154 Parallel SCSI Interface Product Manual, Rev. A Table 66: Self-test mode summary 8.3 Alternate error detection for the asynchronous information phases (AIP)—Command, Message, and Status 8.3.1 Error detection for asynchronous information phases This section describes an enhanced error detection me...
Page 169 - Covered signals; functions in a future standard.
Parallel SCSI Interface Product Manual, Rev. A 155 8.3.2.1 Covered signals Table 67 defines the signals to be covered by the protection code and their bit locations in the 21-bit code word. When a SCSI device receives an information byte, it also latches the state of the other SCSI signals and value...
Page 171 - Code description; The protection code (see Table 68) is a cyclic binary BCH code.; Protection code; signs represent an; Error detection properties; Data In
Parallel SCSI Interface Product Manual, Rev. A 157 8.3.2.2 Code description The protection code (see Table 68) is a cyclic binary BCH code. Table 68: Protection code The BCH protection code is a cyclic code with a generator polynomial of x 6 + x 5 + x 2 + 1. The canonical form of the code generator ...
Page 173 - Case 1—Power off during removal or insertion; the completion of the insertion or removal event.; Case 4—Current I/O process allowed during insertion or removal
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 off during physical reconfiguration. 8.4.3 Case 2—RST signal asserted continuously during removal or insertion a. RST signal shall be asserted continuously by the ini...
Page 175 - Index
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, 150 ACA. see Auto Contingent AllegianceACK. see Acknowledgeacknowledge SCSI bus signal 15 active pointer 110, 140 adapter host 14 Addi...