Date: Nov 23, 1989 X3T9.2/89-094R5 To: X3T9.2 Committee (SCSI) From: George Penokie (IBM) Subject: 16 Bit Data Path on a Single 68 pin Connector Section 3 Issues -Redefine SCSI address and SCSI ID terms Section 4 Issues -Termination of the cable -The maximum number of devices should be made to be 16 if the P cable is used. -The maximum number of devices should be made to be 32 if the P/Q cable is used. -Add in the Q cable changes. Section 5 Issues -Some wording changes in section 5.1.2 ARBITRATION Phase are required to indicate there are now 32 devices allowed on the bus. -Some changes in section 5.1.5.3 Wide Data Transfer are required to indicate there is another cabling option. -Add in the Q cable changes Section 7 Issues -The copy commands segment Descriptor does not have room for a 5 bit source address and a 5 bit destination address. -Make a new set of Descriptors to handle a larger number of addresses. -Make a new ASC and ASCQ to handle unsupported SCSI addresses -Add into the Inquiry data the 16/32 bit addressing information and the ACKB/REQB information. Section 8, 9, 10, 12, 13, 14, 15, and 16 Issues -The Release command and Reserve command do not have room for a 5 bit third party device ID -Make 10 byte commands for both the Release and Reserve commands Section 3 changes recommended to implement a single 68 pin connector 3.1. Glossary | SCSI address. The Hexadecimal Representation of the unique | address (0-31) assigned to an SCSI device. This address would normally be assigned and set in the SCSI device during system installation. SCSI ID. The bit-significant representation of the SCSI address | referring to one of the signal lines DB(31-0). Section 4 changes recommended to implement a single 68 pin connector 4.1. Physical Description | Two cabling alternatives are specified: | (1) SCSI devices are daisy-chained together using a common 50-conductor A cable and, optionally, a 68-conductor B cable. Both ends of all cables are terminated. All signals are common between all SCSI devices on the A cable. In systems that employ the B cable wide SCSI option, wide SCSI devices additionally connect to the B cable. Various width SCSI devices may be mixed. | (2) SCSI devices are daisy-chained together using a common | 68-conductor P cable and, optionally, a 68-conductor Q cable. | Both ends of all cables are terminated. All signals are common | between all SCSI devices on the P cable. In systems that employ | the Q cable wide SCSI option, wide SCSI devices additionally | connect to the Q cable. Various width SCSI devices may be mixed. The single-ended and differential alternatives are mutually | exclusive within a system. The A/B cable and P/Q cable | alternatives are mutually exclusive within a system. Physical | devices with A and A/B cable connectors may be attached to P and | P/Q cables. Physical devices with P and P/Q cable connectors | shall not be connected to A or A/B cables. 4.2.1. Single-Ended Cable A 50-conductor flat cable or 25-signal twisted-pair cable shall be used for the A cable. A 68-conductor flat cable or 34-signal | twisted-pair cable shall be used for the P cable, B cable, and Q | cable if the wide SCSI option is implemented. If twisted-pair cables are used, then twisted pairs in the cable shall be wired to physically opposing contacts in the connector. 4.2.2. Differential Cable A 50-conductor flat cable or 25-signal twisted-pair cable shall be used for the A cable. A 68-conductor flat cable or 34-signal | twisted-pair cable shall be used for the P cable, B cable, and Q | cable if the wide SCSI option is implemented. If twisted-pair cables are used, then twisted pairs in the cable shall be wired to physically opposing contacts in the connector. 4.3.1. Nonshielded Connector Requirements Two nonshielded connector alternatives are specified for the A | cable, one nonshielded connector is specified for the P cable, B | cable, and Q cable. | 4.3.1.3. Nonshielded Connector - P Cable, B cable, and Q cable The nonshielded high-density SCSI device connector for the P | cable, B cable, and Q cable (Figure 4-1) shall be a 68-conductor connector consisting of two rows of 34 female contacts with adjacent contacts 1.27 mm (0.05 in) apart. The nonmating portion of the connector is shown for reference only. The nonshielded high-density cable connector for the P cable, B | cable, and Q cable (Figure 4-2) shall be a 68-conductor connector consisting of two rows of 34 male contacts with adjacent contacts 1.27 mm (0.05 in) apart. The nonmating portion of the connector is shown for reference only. 4.3.2. Shielded Connector Requirements Two shielded connector alternatives are specified for the A | cable and one shielded connector is specified for the P cable, B | cable, and Q cable. The connector shielding system should provide a dc resistance of less than 10 milliohms from the cable shield at its termination point to the SCSI device enclosure. | 4.3.2.3. Shielded Connector - P Cable, B cable, and Q cable The shielded high-density SCSI device connector for the P cable, | B cable, and Q cable (Figure 4-5) is a 68-conductor connector consisting of two rows of 34 female contacts with adjacent contacts 1.27 mm (0.05 in) apart. The nonmating portion of the connector is shown for reference only. | The shielded high-density cable connector for the P cable, B | cable, and Q cable (Figure 4-6) is a 68-conductor connector consisting of two rows of 34 male contacts with adjacent contacts 1.27 mm (0.05 in) apart. The nonmating portion of the connector is shown for reference only. Figure 4-1: 50/68-Contact Nonshielded High-Density SCSI Device Connector | (A Cable/B Cable/P Cable/Q Cable) Figure 4-2: 50/68-Contact Nonshielded High-Density Cable Connector | (A Cable/B Cable/P Cable/Q Cable) Figure 4-5: 50/68-Contact Shielded High-density SCSI Device Connector | (A Cable/B Cable/P Cable/Q Cable) Figure 4-6: 50/68-Contact Shielded High-density Cable Connector | (A Cable/B Cable/P Cable/Q Cable) 4.3.3. Connector Contact Assignments The connector contact assignments are defined in Tables 4-1 through 4-7. Table 4-1 defines which of the other four tables to use and which set of contact assignments to use. Table 4-1: Cross-Reference to Connector Contact Assignments ============================================================================== Driver/ Contact Receiver Connector Assignment Contact Connector Type Type Cable Figure Table Set ------------------------------------------------------------------------------ Nonshielded Alternative 1 Single-Ended A 4-1 & 4-2 4-2 2 Nonshielded Alternative 1 Single-Ended B 4-1 & 4-2 4-3 |Nonshielded Alternative 1 Single-Ended P 4-1 & 4-2 4-4 |Nonshielded Alternative 1 Single-Ended Q 4-1 & 4-2 4-5 Nonshielded Alternative 1 Differential A 4-1 & 4-2 4-6 2 Nonshielded Alternative 1 Differential B 4-1 & 4-2 4-7 |Nonshielded Alternative 1 Differential P 4-1 & 4-2 4-8 |Nonshielded Alternative 1 Differential Q 4-1 & 4-2 4-9 Nonshielded Alternative 2 Single-Ended A 4-3 & 4-4 4-2 1 Nonshielded Alternative 2 Differential A 4-3 & 4-4 4-5 1 Shielded Alternative 1 Single-Ended A 4-5 & 4-6 4-2 2 Shielded Alternative 1 Single-Ended B 4-5 & 4-6 4-3 |Shielded Alternative 1 Single-Ended P 4-5 & 4-6 4-4 |Shielded Alternative 1 Single-Ended Q 4-5 & 4-6 4-5 Shielded Alternative 1 Differential A 4-5 & 4-6 4-6 2 Shielded Alternative 1 Differential B 4-5 & 4-6 4-7 |Shielded Alternative 1 Differential P 4-5 & 4-6 4-8 |Shielded Alternative 1 Differential Q 4-5 & 4-6 4-9 Shielded Alternative 2 Single-Ended A 4-7 & 4-8 4-2 2 Shielded Alternative 2 Differential A 4-7 & 4-8 4-5 2 ============================================================================== | Table 4-4: Single-Ended Contact Assignments - P cable | |============================================================================== | Connector Cable Connector | Signal Contact Conductor Contact Signal | Name Number Number Number Name |------------------------------------------------------------------------------ | GROUND 1 1 3 2 35 -DB(12) | GROUND 2 3 3 4 36 -DB(13) | GROUND 3 5 3 6 37 -DB(14) | GROUND 4 7 3 8 38 -DB(15) | GROUND 5 9 3 10 39 -DB(P1) | GROUND 6 11 3 12 40 -DB(0) | GROUND 7 13 3 14 41 -DB(1) | GROUND 8 15 3 16 42 -DB(2) | GROUND 9 17 3 18 43 -DB(3) | GROUND 10 19 3 20 44 -DB(4) | GROUND 11 21 3 22 45 -DB(5) | GROUND 12 23 3 24 46 -DB(6) | GROUND 13 25 3 26 47 -DB(7) | GROUND 14 27 3 28 48 -DB(P) | GROUND 15 29 3 30 49 GROUND | GROUND 16 31 3 32 50 GROUND | TERMPWR 17 33 3 34 51 TERMPWR | TERMPWR 18 35 3 36 52 TERMPWR | RESERVED 19 37 3 38 53 RESERVED | GROUND 20 39 3 40 54 GROUND | GROUND 21 41 3 42 55 -ATN | GROUND 22 43 3 44 56 GROUND | GROUND 23 45 3 46 57 -BSY | GROUND 24 47 3 48 58 -ACK | GROUND 25 49 3 50 59 -RST | GROUND 26 51 3 52 60 -MSG | GROUND 27 53 3 54 61 -SEL | GROUND 28 55 3 56 62 -C/D | GROUND 29 57 3 58 63 -REQ | GROUND 30 59 3 60 64 -I/O | GROUND 31 61 3 62 65 -DB(8) | GROUND 32 63 3 64 66 -DB(9) | GROUND 33 65 3 66 67 -DB(10) | GROUND 34 67 3 68 68 -DB(11) |============================================================================== NOTES: (1) The minus sign next to a signal indicates active low. (2) The conductor number refers to the conductor position when using 0.025- inch centerline flat ribbon cable. Other cable types may be used to implement equivalent contact assignments. (3) 8 bit devices which connected to the P-cable shall leave the following signals open: -DB(12) -DB(13) -DB(14) -DB(15) -DB(P1) -DB(8) -DB(9) -DB(10) -DB(11) All other signals shall be connected as defined. | Table 4-5: Single-Ended Contact Assignments - Q cable | |============================================================================== | Connector Cable Connector | Signal Contact Conductor Contact Signal | Name Number Number Number Name |------------------------------------------------------------------------------ | GROUND 1 1 3 2 35 GROUND | GROUND 2 3 3 4 36 OPEN | GROUND 3 5 3 6 37 OPEN | GROUND 4 7 3 8 38 OPEN | GROUND 5 9 3 10 39 OPEN | GROUND 6 11 3 12 40 OPEN | GROUND 7 13 3 14 41 OPEN | GROUND 8 15 3 16 42 OPEN | GROUND 9 17 3 18 43 OPEN | GROUND 10 19 3 20 44 OPEN | GROUND 11 21 3 22 45 -ACKB | GROUND 12 23 3 24 46 GROUND | GROUND 13 25 3 26 47 -REQB | GROUND 14 27 3 28 48 -DB(16) | GROUND 15 29 3 30 49 -DB(17) | GROUND 16 31 3 32 50 -DB(18) | TERMPWR 17 33 3 34 51 TERMPWRB | TERMPWR 18 35 3 36 52 TERMPWRB | GROUND 19 37 3 38 53 RESERVED | GROUND 20 39 3 40 54 -DB(19) | GROUND 21 41 3 42 55 -DB(20) | GROUND 22 43 3 44 56 -DB(21) | GROUND 23 45 3 46 57 -DB(22) | GROUND 24 47 3 48 58 -DB(23) | GROUND 25 49 3 50 59 -DB(P2) | GROUND 26 51 3 52 60 -DB(24) | GROUND 27 53 3 54 61 -DB(25) | GROUND 28 55 3 56 62 -DB(26) | GROUND 29 57 3 58 63 -DB(27) | GROUND 30 59 3 60 64 -DB(28) | GROUND 31 61 3 62 65 -DB(29) | GROUND 32 63 3 64 66 -DB(30) | GROUND 33 65 3 66 67 -DB(31) | GROUND 34 67 3 68 68 -DB(P3) |============================================================================== NOTES: (1) The minus sign next to a signal indicates active low. (2) The conductor number refers to the conductor position when using 0.025- inch centerline flat ribbon cable. Other cable types may be used to implement equivalent contact assignments. | Table 4-8: Differential Contact Assignments - P cable | |============================================================================== | Connector Cable Connector | Signal Contact Conductor Contact Signal | Name Number Number Number Name |------------------------------------------------------------------------------ | +DB(12) 1 1 3 2 35 -DB(12) | +DB(13) 2 3 3 4 36 -DB(13) | +DB(14) 3 5 3 6 37 -DB(14) | +DB(15) 4 7 3 8 38 -DB(15) | +DB(P1) 5 9 3 10 39 -DB(P1) | GROUND 6 11 3 12 40 GROUND | +DB(0) 7 13 3 14 41 -DB(0) | +DB(1) 8 15 3 16 42 -DB(1) | +DB(2) 9 17 3 18 43 -DB(2) | +DB(3) 10 19 3 20 44 -DB(3) | +DB(4) 11 21 3 22 45 -DB(4) | +DB(5) 12 23 3 24 46 -DB(5) | +DB(6) 13 25 3 26 47 -DB(6) | +DB(7) 14 27 3 28 48 -DB(7) | +DB(P) 15 29 3 30 49 -DB(P) | DIFFSENS 16 31 3 32 50 GROUND | TERMPWR 17 33 3 34 51 TERMPWR | TERMPWR 18 35 3 36 52 TERMPWR | RESERVED 19 37 3 38 53 RESERVED | +ATN 20 39 3 40 54 -ATN | GROUND 21 41 3 42 55 GROUND | +BSY 22 43 3 44 56 -BSY | +ACK 23 45 3 46 57 -ACK | +RST 24 47 3 48 58 -RST | +MSG 25 49 3 50 59 -MSG | +SEL 26 51 3 52 60 -SEL | +C/D 27 53 3 54 61 -C/D | +REQ 28 55 3 56 62 -REQ | +I/O 29 57 3 58 63 -I/O | GROUND 30 59 3 60 64 GROUND | +DB(8) 31 61 3 62 65 -DB(8) | +DB(9) 32 63 3 64 66 -DB(9) | +DB(10) 33 65 3 66 67 -DB(10) | +DB(11) 34 67 3 68 68 -DB(11) |============================================================================== NOTES: (1) The conductor number refers to the conductor position when using 0.025- inch centerline flat ribbon cable. Other cable types may be used to implement equivalent contact assignments. (2) 8 bit devices which connected to the P-cable shall leave the following signals open: -DB(12) -DB(13) -DB(14) -DB(15) -DB(P1) -DB(8) -DB(9) -DB(10) -DB(11) +DB(12) +DB(13) +DB(14) +DB(15) +DB(P1) +DB(8) +DB(9) +DB(10) +DB(11) All other signals shall be connected as defined. | Table 4-9: Differential Contact Assignments - Q cable | |============================================================================== | Connector Cable Connector | Signal Contact Conductor Contact Signal | Name Number Number Number Name |------------------------------------------------------------------------------ | GROUND 1 1 3 2 35 GROUND | OPEN 2 3 3 4 36 OPEN | OPEN 3 5 3 6 37 OPEN | OPEN 4 7 3 8 38 OPEN | OPEN 5 9 3 10 39 OPEN | OPEN 6 11 3 12 40 OPEN | OPEN 7 13 3 14 41 OPEN | OPEN 8 15 3 16 42 OPEN | OPEN 9 17 3 18 43 OPEN | OPEN 10 19 3 20 44 OPEN | +ACKB 11 21 3 22 45 -ACKB | GROUND 12 23 3 24 46 GROUND | +REQB 13 25 3 26 47 -REQB | +DB(16) 14 27 3 28 48 -DB(16) | +DB(17) 15 29 3 30 49 -DB(17) | +DB(18) 16 31 3 32 50 -DB(18) | TERMPWRB 17 33 3 34 51 TERMPWRB | TERMPWRB 18 35 3 36 52 TERMPWRB | RESERVED 19 37 3 38 53 RESERVED | +DB(19) 20 39 3 40 54 -DB(19) | +DB(20) 21 41 3 42 55 -DB(20) | +DB(21) 22 43 3 44 56 -DB(21) | +DB(22) 23 45 3 46 57 -DB(22) | +DB(23) 24 47 3 48 58 -DB(23) | +DB(P2) 25 49 3 50 59 -DB(P2) | +DB(24) 26 51 3 52 60 -DB(24) | +DB(25) 27 53 3 54 61 -DB(25) | +DB(26) 28 55 3 56 62 -DB(26) | +DB(27) 29 57 3 58 63 -DB(27) | +DB(28) 30 59 3 60 64 -DB(28) | +DB(29) 31 61 3 62 65 -DB(29) | +DB(30) 32 63 3 64 66 -DB(30) | +DB(31) 33 65 3 66 67 -DB(31) | +DB(P3) 34 67 3 68 68 -DB(P3) |============================================================================== NOTES: (1) The minus sign next to a signal indicates active low. (2) The conductor number refers to the conductor position when using 0.025- inch centerline flat ribbon cable. Other cable types may be used to implement equivalent contact assignments. 4.4.3. Terminator Power IMPLEMENTORS NOTE: Regulatory agencies may require limiting maximum (short circuit) current to the terminator power lines. | Recommended current limiting is 1.5 amperes for TERMPWR on A | cables, 2 amperes for TERMPWR on P cables, and 2 amperes for TERMPWRB. For systems utilizing multiple initiators, the initiators may be configured with option straps or current limiting devices. Maximum available current should not exceed 5 amperes. | Single-ended SCSI devices providing terminator power on cable P, | cable B, or cable Q shall have the following characteristics: Vterm = 4.25 to 5.25 volts dc 1500 mA minimum source drive capability | Differential SCSI devices providing terminator power on cable P, | cable B, or cable Q shall have the following characteristics: Vterm = 4.0 to 5.25 volts dc 1000 mA minimum source drive capability 4.5. SCSI Bus Communication on the SCSI bus is allowed between only two SCSI devices at any given time. There is a maximum of 8 SCSI devices | on an A/B cabled system. There is a maximum of 16 SCSI devices on | a P cabled system and 32 SCSI devices on a P/Q cabled system. Each SCSI device has an SCSI ID bit assigned as shown in Figure 4-12. | An initiator may address up to 8 peripheral devices that | are connected to a target on an A/B cabled system. An initiator | may address up to 32 peripheral devices that are connected to a | target on a P/Q cabled system. Three sample system configurations are shown in Figure 4-13. SCSI ID bits for A, A/B, P, and P/Q peripheral devices: DB(7) DB(6) DB(5) DB(4) DB(3) DB(2) DB(1) DB(0) <-- DATA BUS | | | | | | | | | | | | | | | SCSI ID = 0 | | | | | | | | | | | | | SCSI ID = 1 | | | | | | | | | | | SCSI ID = 2 | | | | | | | | | SCSI ID = 3 | | | | | | | SCSI ID = 4 | | | | | SCSI ID = 5 | | | SCSI ID = 6 | SCSI ID = 7 SCSI ID bits for P, and P/Q peripheral devices: | DB(15) DB(14) DB(13) DB(12) DB(11) DB(10) DB(9) DB(8) <-- DATA BUS | | | | | | | | | | | | | | | | | SCSI ID = 8 | | | | | | | | | | | | | | | SCSI ID = 9 | | | | | | | | | | | | | SCSI ID = 10 | | | | | | | | | | | SCSI ID = 11 | | | | | | | | | SCSI ID = 12 | | | | | | | SCSI ID = 13 | | | | | SCSI ID = 14 | | | SCSI ID = 15 SCSI ID bits for P/Q peripheral devices: | DB(23) DB(22) DB(21) DB(20) DB(19) DB(18) DB(17) DB(16) <-- DATA BUS | | | | | | | | | | | | | | | | | SCSI ID = 16 | | | | | | | | | | | | | | | SCSI ID = 17 | | | | | | | | | | | | | SCSI ID = 18 | | | | | | | | | | | SCSI ID = 19 | | | | | | | | | SCSI ID = 20 | | | | | | | SCSI ID = 21 | | | | | SCSI ID = 22 | | | SCSI ID = 23 SCSI ID bits for P/Q peripheral devices: | DB(31) DB(30) DB(29) DB(28) DB(27) DB(26) DB(25) DB(24) <-- DATA BUS | | | | | | | | | | | | | | | | | SCSI ID = 24 | | | | | | | | | | | | | | | SCSI ID = 25 | | | | | | | | | | | | | SCSI ID = 26 | | | | | | | | | | | SCSI ID = 27 | | | | | | | | | SCSI ID = 28 | | | | | | | SCSI ID = 29 | | | | | SCSI ID = 30 | | | SCSI ID = 31 Figure 4-12: SCSI ID Bits | Up to 8 SCSI devices can be supported on the SCSI bus on | an A/B cabled system. Up to 32 SCSI devices can be supported on | the SCSI bus on a P/Q cabled system. They can be any combination of initiators and targets. Information transfers on the DATA BUS are asynchronous and follow a defined REQ/ACK handshake protocol. One byte of information may be transferred with each handshake on the A cable | and, if the wide data transfer option is implemented, one or two | bytes of information may be transferred with each handshake on the | P cable, two bytes of information may be transferred with each | handshake on the Q cable, or one or three bytes of information may be transferred with each handshake on the B cable. An option is defined for synchronous data transfer. 4.6. SCSI Bus Signals | There are a total of 18 signals on the A cable, 27 on the P | cable, 20 signals on the Q cable, and 29 signals on the B cable. A total of 11 signals are used for control and 36 are used for data, including parity. These signals are described as follows: | REQ (REQUEST). A signal driven by a target on the A cable or the | P cable to indicate a request for a REQ/ACK data transfer handshake. | REQB (REQUEST). A signal driven by a target on the B cable or the | Q cable to indicate a request for a REQB/ACKB data transfer handshake. ACK (ACKNOWLEDGE). A signal driven by an initiator on the A | cable or the P cable to indicate an acknowledgment for a REQ/ACK data transfer handshake. ACKB (ACKNOWLEDGE). A signal driven by an initiator on the B | cable or the Q cable to indicate an acknowledgment for a REQB/ACKB data transfer handshake. DB(31-8,P1,P2,P3) (DATA BUS). Twenty-four data-bit signals, plus three parity-bit signals that form an extension to the DATA BUS. DB(P1,P2,P3) are parity bits for DB(15-8), DB(23-16), and | DB(31-24) respectively. On SCSI devices which support 16 IDs | DB(15) has the highest priority in the DB(15-8) byte during the | ARBITRATION phase. The priority decreases downward to DB(8). | DB(15) has a lower priority than DB(0). On SCSI devices which | support 32 IDs DB(23) has the highest priority in the DB(23-16) | byte and DB(31) has the highest priority in the DB(31-24) byte | during the ARBITRATION phase. The priority decreases downward to | DB(16) in the DB(23-16) byte and to DB(24) in the DB(31-24) byte. | DB(23) has a lower priority than DB(8) and DB(31) has a lower | priority than DB(16). A data bit is defined as one when the signal value is true and is defined as zero when the signal value is false. Data parity DB(Px) shall be odd. 4.6.3. Signal Sources Table 4-8: Signal Sources ============================================================================== A Cable Signals B Cable Signals ------------------------------- ------------------------ C/D, I/O, MSG, ACK, DB(7-0) DB(31-8) Bus Phase BSY SEL REQ ATN DB(P) REQB ACKB DB(P1,P2,P3) ----------- ---- ---- ---- ---- ------- ---- ---- ------------ BUS FREE None None None None None None None None ARBITRATION All Win None None S ID None None None SELECTION I&T Init None Init Init None None None RESELECTION I&T Targ Targ Init Targ None None None COMMAND Targ None Targ Init Init None None None DATA IN Targ None Targ Init Targ Targ Init Targ DATA OUT Targ None Targ Init Init Targ Init Init STATUS Targ None Targ Init Targ None None None MESSAGE IN Targ None Targ Init Targ None None None MESSAGE OUT Targ None Targ Init Init None None None =============================================================================== | P cable Signals Q Cable Signals | ----------------------------------------- --------------------- | C/D, 8,16,32 16,32 ID 32 ID | I/O, ID Dev Device Device | MSG, ACK, DB(7-0) DB(15-8) DB(31-16) | Bus Phase BSY SEL REQ ATN DB(P) DB(P1) REQB ACKB DB(P2,P3) | ----------- ---- ---- ---- ---- ------- -------- ---- ---- --------- | BUS FREE None None None None None None None None None | ARBITRATION All Win None None S ID S ID None None S ID | SELECTION I&T Init None Init Init Init None None Init | RESELECTION I&T Targ Targ Init Targ Targ None None Targ | COMMAND Targ None Targ Init Init None None None None | DATA IN Targ None Targ Init Targ Targ Targ Init Targ | DATA OUT Targ None Targ Init Init Init Targ Init Init | STATUS Targ None Targ Init Targ None None None None | MESSAGE IN Targ None Targ Init Targ None None None None | MESSAGE OUT Targ None Targ Init Init None None None None |============================================================================== All: The signal shall be driven by all SCSI devices that are actively arbitrating. S ID: A unique data bit (the SCSI ID) shall be driven by each | SCSI device that is actively arbitrating; the other data bits shall be released (i.e., not driven) by this SCSI device. The parity bit(s) (DB(P)) may be released or driven to the true state, but shall never be driven to the false state during this phase. I&T: The signal shall be driven by the initiator, target, or both, as specified in the SELECTION phase and RESELECTION phase. Init: If driven, this signal shall be driven only by the active initiator. None: The signal shall be released; that is, not be driven by any SCSI device. The bias circuitry of the bus terminators pulls the signal to the false state. Win: The signal shall be driven by the one SCSI device that wins arbitration. Targ: If the signal is driven, it shall be driven only by the active target. Section 5 changes recommended to implement a single 68 pin connector 5.1.2. ARBITRATION Phase (4) After waiting at least an arbitration delay (measured from its assertion of the BSY signal) the SCSI device shall examine the DATA BUS. If a higher priority SCSI ID bit is true on the DATA BUS (DB(7) is the highest) , then the SCSI device has lost the arbitration and the SCSI device may release its signals and return to Step (1). If no higher priority SCSI ID bit is true on the DATA BUS, then the SCSI device has won the arbitration and it shall assert the SEL signal. Any other SCSI device that is participating in the ARBITRATION phase has lost the arbitration and shall release the BSY signal and its SCSI ID bit within a bus clear delay after the SEL signal becomes true. An SCSI device | that loses arbitration may return to Step (1). The SCSI ID | priority is shown below: | Priority | Highest --> Lowest | SCSI ID SCSI ID | | A Cable 7 0 | A/B Cable 7 0 | P cable 7 0 15 8 | P/Q Cable 7 0 15 8 23 16 31 24 NOTE: The SCSI ID bit is a single bit on the DATA BUS that corresponds to the SCSI device's unique SCSI address. All other | DATA BUS bits shall be released by the SCSI device. Parity is not valid during the ARBITRATION phase. During the ARBITRATION | phase, DB(P), DB(P1), DB(P2), or DB(P3) may be released or asserted, but shall not be actively driven false. 5.1.5.3. Wide Data Transfer 5.1.5.3.1. A/B Cable Wide Data Transfer During 16-bit wide data transfers, the first logical data byte for each data phase shall be transferred across the DB(7-0,P) signals on the A cable and the second logical data byte shall be transferred across the DB(15-8,P1) signals on the B cable. Subsequent pairs of data bytes are likewise transferred in parallel across the A and B cables (see Figure 5-1) During 32-bit wide data transfers, the first logical data byte for each data phase shall be transferred across the DB(7-0,P) signals on the A cable, the second, third, and fourth logical data bytes shall be transferred across the DB(15-8,P1), DB(23-16,P2), and DB(31-24,P3) signals, respectively, on the B cable. Subsequent pairs of data bytes are likewise transferred in parallel across the A and B cables (see Figure 5-1). 5.1.5.3.1. P/Q Cable Wide Data Transfer During 16-bit wide data transfers, the first and second logical data bytes for each data phase shall be transferred across the DB(7-0,P) and DB(15-8,P2) signals, respectively, on the P cable. Subsequent pairs of data bytes are likewise transferred in parallel across the P cable (see Figure 5-1). During 32-bit wide data transfers, the first and second logical data bytes for each data phase shall be transferred across the DB(7-0,P) and DB(15-8,P2) signals, respectively, on the P cable, and the third and fourth logical data bytes shall be transferred across the DB(23-16,P2) and DB(31-24,P3) signals, respectively, on the Q cable. Subsequent pairs of data bytes are likewise transferred in parallel across the P and Q cables (see Figure 5-1). When transferring bytes W, X, Y and Z across the three bus widths, they are transferred as shown below: Hand- 8-bit 16-bit 32-bit | shake P cable ______ ______ # A Cable B Cable A Cable / B Cable \ A Cable +-------+ +-------+-------+ +-------------------------------+ 1 | W | | X | W | | Z | Y | X | W | +-------+ +-------+-------+ +-------+-------+-------+-------+ 2 | X | | Z | Y | 31...24 23...16 15....8 7.....0 +-------+ +-------+-------+ Bit Number | 3 | Y | 15....8 7.....0 ______ _____ _______ ______ | +-------+ / Q Cable \/ P Cable \ | 4 | Z | Bit Number +-------+-------+-------+-------+ | +-------+ | Z | Y | X | W | | 7.....0 +-------+-------+-------+-------+ | 31...24 23...16 15....8 7.....0 | Bit Number Bit Number NOTE: This figure does not represent how these bytes are stored in the initiator's memory, which may be different. Figure 5-1: Wide SCSI Byte Ordering To ensure proper data integrity, certain sequence requirements | shall be met between the REQ/ACK handshakes on the A and P cables, | and the REQB/ACKB handshakes on the B and Q cables: (1) The REQB and ACKB signals shall only be asserted during data phases while a nonzero wide data transfer agreement is in | effect on a B or Q cable system. These signals shall not be asserted during other phases. (3) The information transfer procedures defined in 5.1.5.1 and 5.1.5.2 for the A cable (the REQ, ACK, and DB(7-0,P) signals) and | the P cable (the REQ, ACK, DB(15-8,P1) signals) shall also apply to the B cable (the REQB, ACKB, and DB(31-8,P1,P2,P3) signals | and the Q cable (the REQB, ACKB, and DB(31-8,P1,P2,P3) signals, The only means available for a target to manage the timing relationship between the signals on the two cables is its management of the REQ and REQB signals. Similarly, the only means for the initiator to manage the timing between the two cables is its management of the ACK and ACKB signals. Section 7 changes recommended to implement a single 68 pin connector Table 7-7: COPY Function Codes ================================================================= Peripheral Device Type COPY Segment ---------------------- Function Descriptor Source Destination Code Table Comments ----------------------------------------------------------------- Direct-Access Sequential-Access 0 7-8 (0,4,5,7) (1,2,3,9) Sequential-Access Direct-Access 1 7-8 (1,3,9) (0,4,7) Direct-Access Direct-Access 2 7-9 (0,4,5,7) (0,4,7) Sequential-Access Sequential-Access 3 7-10 (1,3,9) (1,2,3,9) Sequential-Access Sequential-Access 4 7-11 Image Copy (1) (1) Direct-Access Sequential-Access 5 7-new1 32 address (0,4,5,7) (1,2,3,9) Sequential-Access Direct-Access 6 7-new1 32 address (1,3,9) (0,4,7) Direct-Access Direct-Access 7 7-new2 32 address (0,4,5,7) (0,4,7) Sequential-Access Sequential-Access 8 7-new3 32 address (1,3,9) (1,2,3,9) Sequential-Access Sequential-Access 9 7-new4 Image Copy; (1) (1) 32 address ================================================================= The numbers in parenthesis are the peripheral device type codes (see Table 7-17). COPY function code: 00h Direct-access to sequential-access 01h Sequential-access to writable direct-access 02h Direct-access to writable direct-access 03h Sequential-access to sequential-access 04h Sequential-access image copy 05h Direct-access to sequential-access 06h Sequential-access to writable direct-access 07h Direct-access to writable direct-access 08h Sequential-access to sequential-access 09h Sequential-access image copy 0Ah - 0Fh Reserved 10h - 1Fh Vendor specific For the COMPARE command the destination direct-access device does not have to be a writable device. 7.2.3.3. COPY Function Codes 00h, 01h, 05h, and 06h The format of the segment descriptors for COPY transfers between direct-access and sequential-access devices is specified in Table 7-8 for COPY function codes 00h and 01h; it is specified in Table 7-new1 for COPY function codes 05h and 06h. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-8: Segment Descriptor for COPY Function Codes 00h and 01h [Table 7-8 is unchanged, so it is not shown here] Table 7-new1: Segment Descriptor for Function Codes 05h and 06h ============================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================== 0 | Source Address | -----+------+---------------------------+--------------------+ 1 | CAT | Reserved | Source LUN | -----+------+---------------------------+--------------------+ 2 | Destination Address | -----+----------------------------------+--------------------+ 3 | Reserved | Destination LUN | -----+----------------------------------+--------------------+ 4 | Reserved | -----+-------------------------------------------------------+ 5 | (MSB) | -----+- - Sequential-Access Device Block Length - -+ 7 | (LSB) | -----+-------------------------------------------------------+ 8 | (MSB) | - - -+- - Direct-Access Device Number of Blocks - -+ 11 | (LSB) | -----+-------------------------------------------------------+ 12 | (MSB) | - - -+- - Direct-Access Device Logical Block Address - -+ 15 | (LSB) | ============================================================== 7.2.3.4. COPY Function Codes 02h and 07h The format of the segment descriptors for COPY transfers among direct-access devices is specified in Table 7-9 for COPY function code 02h and is specified in Table 7-new2 for COPY function code 07h. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-9: Segment Descriptor for COPY Function Code 02h [Table 7-9 is unchanged, so it is not shown here] Table 7-new2: Segment Descriptor for Function Code 07h ============================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================== 0 | Source Address | -----+------+---------------------------+--------------------+ 1 | CAT | Reserved | Source LUN | -----+------+---------------------------+--------------------+ 2 | Destination Address | -----+------+---------------------------+--------------------+ 3 | DC | Reserved | Destination LUN | -----+------+---------------------------+--------------------+ 4 | (MSB) | -----+--- Number of Blocks ---+ 7 | (LSB) | -----+-------------------------------------------------------+ 8 | (MSB) | - - -+- - Source Logical Block Address - -| 11 | (LSB) | -----+-------------------------------------------------------+ 12 | (MSB) | - - -+- - Destination Logical Block Address - -| 15 | (LSB) | ============================================================== 7.2.3.4. COPY Function Codes 03h and 08h The format of the segment descriptors for COPY transfers among sequential-access devices is specified in Table 7-10 for COPY function code 03h and is specified in Table 7-new3 for COPY function code 08h. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-10: Segment Descriptor for COPY Function Code 03h [Table 7-10 is unchanged, so it is not shown here] Table 7-new3: Segment Descriptor for Function Code 08h ============================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================== 0 | Source Address | -----+------+---------------------------+--------------------+ 1 | CAT | Reserved | Source LUN | -----+------+---------------------------+--------------------+ 2 | Destination Address | -----+------+---------------------------+--------------------+ 3 | DC | Reserved | Destination LUN | -----+------+---------------------------+--------------------+ 4 | Reserved | -----+-------------------------------------------------------+ 5 | Reserved | -----+-------------------------------------------------------+ 6 | (MSB) | -----+--- Source Block Length ---+ 8 | (LSB) | -----+-------------------------------------------------------+ 9 | (MSB) | - - -+- - Destination Block Length - -| 11 | (LSB) | -----+-------------------------------------------------------+ 12 | (MSB) | - - -+- - Number of Blocks - -| 15 | (LSB) | ============================================================== 7.2.3.4. COPY Function Codes 04h and 09h The format of the segment descriptors for image COPY transfers among sequential-access devices is specified in Table 7-11 for COPY function code 04h and is specified in Table 7-new4 for COPY function code 09h. The segment descriptor may be repeated up to 256 times within the parameter list length specified in the command descriptor block. Table 7-11: Segment Descriptor for COPY Function Code 04h [Table 7-11 is unchanged, so it is not shown here] Table 7-new4: Segment Descriptor for Function Code 09h ============================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================== 0 | Source Address | -----+----------------------------------+--------------------+ 1 | Reserved | Source LUN | -----+----------------------------------+--------------------+ 2 | Destination Address | -----+----------------------------------+--------------------+ 3 | Reserved | Destination LUN | -----+----------------------------------+--------------------+ 4 | (MSB) | -----+--- Count ---+ 5 | (LSB) | -----+-------------------------------------------------------+ 6 | | - - -+- - Reserved - -| 7 | | -----+-------------------------------------------------------+ 8 | | - - -+- - Vendor Specific - -| 11 | | ============================================================== 7.2.5.1. Standard INQUIRY Data The standard INQUIRY data (Table 7-15) contains 36 required bytes, followed by a variable number of vendor-specific parameters. Bytes 56 through 95, if returned, are reserved for future standardization. The target shall return the standard INQUIRY data when the EVPD bit is zero. The standard INQUIRY data format is shown in Table 7-15. Table 7-15: Standard INQUIRY Data Format ============================================================================== Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | ============================================================================== 0 | Peripheral Qualifier | Peripheral Device Type | -----|-----------------------------------------------------------------------| 1 | RMB | Device-Type Qualifier | -----|-----------------------------------------------------------------------| 2 | ISO Version | ECMA Version | ANSI-Approved Version | -----|-----------------------------------------------------------------------| 3 | AENC | TrmIOP | Reserved | Response Data Format | -----|-----------------------------------------------------------------------| 4 | Additional Length (n-+) | -----|-----------------------------------------------------------------------| 5 | Reserved | -----|-----------------------------------------------------------------------| 6 | Reserved |ACKBREQB| Addr32 | Addr16 | -----|-----------------------------------------------------------------------| 7 | RelAdr | WBus32 | WBus16 | Sync | Linked |Reserved| CmdQue | SftRe | -----|-+---------------------------------------------------------------------| 8 | (MSB) | - - -|- - Vendor Identification - -| 15 | (LSB) | -----|-+---------------------------------------------------------------------| 16 | (MSB) | - - -|- - Product Identification - -| 31 | (LSB) | -----|-+---------------------------------------------------------------------| 32 | (MSB) | - - -|- - Product Revision Level - -| 35 | (LSB) | -----|-+---------------------------------------------------------------------| 36 | | - - -|- - Vendor Specific - -| 55 | | -----|-+---------------------------------------------------------------------| 56 | | - - -|- - Reserved - -| 95 | | ============================================================================== | Vendor-Specific Parameters | ============================================================================== 96 to| Vendor-Specific | n | Parameter Bytes | ============================================================================== | A wide SCSI address 32 (Addr32) bit of one indicates that the | device supports 32-bit wide SCSI addresses. A value of zero | indicates that the device does not support 32-bit wide SCSI | addresses. | A wide SCSI address 16 (Addr16) bit of one indicates that the | device supports 16-bit wide SCSI addresses. A value of zero | indicates that the device does not support 16-bit wide SCSI | addresses. | NOTE: If the values of both the Addr16 and Addr32 bits are zero | the device only supports 8-bit wide SCSI addresses. | A ACKB/REQB (ACKBREQB) bit of one indicates that the device | supports a request and acknowledge date transfer handshake on | a B cable or a Q cable. Table 7-41: ASC and ASCQ Assignments ======================================================================== F = FLAG COLUMN (H = HISTORICAL ANOMALY) D = DIRECT ACCESS DEVICE T = SEQUENTIAL ACCESS DEVICE L = PRINTER DEVICE P = PROCESSOR DEVICE W = WRITE ONCE READ MULTIPLE DEVICE R = READ ONLY (CD-ROM) DEVICE S = SCANNER DEVICE O = OPTICAL MEMORY DEVICE M = MEDIA CHANGER DEVICE C = COMMUNICATION DEVICE BYTE 12 13 DTLPWRSOMC DESCRIPTION -- -- ---------------------------------------------------------------- | 5D 00 DTLPWRSOMC SCSI A--RESS NOT SUPPORTED ======================================================================== Sections 8, 12, 13, 15, and 16 changes recommended to implement a single 68 pin connector 8.2. Commands for Direct-Access Devices. The commands for direct-access devices shall be as shown in Tables 8-1 and 8-2. Table 8-1: Commands for Direct-Access Devices(1) ============================================================================== Operation Command Name Code Type Section ------------------------------------------------------------------------------ CHANGE DEFINITION 40h O 7.2.1 COMPARE 39h O 7.2.2 COPY 18h O 7.2.3 COPY AND VERIFY 3Ah O 7.2.4 FORMAT UNIT 04h M 8.2.1 INQUIRY 12h M 7.2.5 LOCK/UNLOCK CACHE 36h O 8.2.2 LOG SELECT 4Ch O 7.2.6 LOG SENSE 4Dh O 7.2.7 MODE SELECT(6) 15h O 7.2.8 MODE SELECT(10) 55h O 7.2.9 MODE SENSE(6) 1Ah O 7.2.10 MODE SENSE(10) 5Ah O 7.2.11 PRE-FETCH 34h O 8.2.3 PREVENT/ALLOW MEDIUM REMOVAL 1Eh O 8.2.4 READ(6) 08h M 8.2.5 READ(10) 28h M 8.2.6 READ BUFFER 3Ch O 7.2.12 READ CAPACITY 25h M 8.2.7 READ DEFECT DATA 37h O 8.2.8 READ LONG 3Eh O 8.2.9 REASSIGN BLOCKS 07h O 8.2.10 RECEIVE DIAGNOSTIC RESULTS 1Ch O 7.2.13 RELEASE(6) 17h M 8.2.11 |RELEASE(10) 57h MP 8.2.11 REQUEST SENSE 03h M 7.2.14 RESERVE(6) 16h M 8.2.12 |RESERVE(10) 56h MP 8.2.12 REZERO UNIT 01h O 8.2.13 ============================================================================== Key: M = Command implementation is mandatory. | MP = Command implementation is mandatory on any device that addresses | more than 8 devices. O = Command implementation is optional. Table 8-2: Commands for Direct-Access Devices(2) ============================================================================== Operation Command Name Code Type Section ------------------------------------------------------------------------------ SEARCH DATA EQUAL 31h O 8.2.14.1 SEARCH DATA HIGH 30h O 8.2.14.2 SEARCH DATA LOW 32h O 8.2.14.3 SEEK(6) 0Bh O 8.2.15 SEEK(10) 2Bh O 8.2.15 SEND DIAGNOSTIC 1Dh M 7.2.15 SET LIMITS 33h O 8.2.16 START STOP UNIT 1Bh O 8.2.17 SYNCHRONIZE CACHE 35h O 8.2.18 TEST UNIT READY 00h M 7.2.16 VERIFY 2Fh O 8.2.19 WRITE(6) 0Ah M 8.2.20 WRITE(10) 2Ah M 8.2.21 WRITE AND VERIFY 2Eh O 8.2.22 WRITE BUFFER 3Bh O 7.2.17 WRITE LONG 3Fh O 8.2.23 WRITE SAME 41h O 8.2.24 ============================================================================== Key: M = Command implementation is mandatory. | MP = Command implementation is mandatory on any device that addresses | more than 8 devices. O = Command implementation is optional. The following operation codes are vendor-specific: 02h, 05h, 06h, 09h, 0Ch, 0Dh, 0Eh, 0Fh, 10h, 11h, 13h, 14h, 19h, 20h, 21h, 22h, 23h, 24h, 26h, 27h, 29h, 2Ch, 2Dh and C0h through FFh. All remaining operation codes are reserved for future standardization. 8.2.11. RELEASE(6) and RELEASE(10) Commands | Peripheral Device Type: Direct-Access, Write-Once, Optical-Memory | Operation Code Type: Mandatory on devices that support more than | 8 SCSI IDs | | Table 8-XX: RELEASE(10) Command | |============================================================================= | Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | |============================================================================= |0 | Operation Code (57h) | |----+--------------------------+--------+--------------------------+--------+ |1 | Logical Unit Number | 3rdPty | Reserved | Extent | |----+--------------------------+--------+--------------------------+--------+ |2 | Reservation Identification | |----+-----------------------------------------------------------------------+ |3 | Third Party Device ID | |----+-----------------------------------------------------------------------+ |4 | Reserved | |----+-----------------------------------------------------------------------+ |5 | Reserved | |----+-----------------------------------------------------------------------+ |6 | Reserved | |----+-----------------------------------------------------------------------+ |7 | Reserved | |----+-----------------------------------------------------------------------+ |8 | Reserved | |----+-----------------------------------------------------------------------+ |9 | Control Byte | |============================================================================= 8.2.12. RESERVE(6) and RESERVE(10) Commands | Peripheral Device Type: Direct-Access, Write-Once, Optical-Memory | Operation Code Type: Mandatory on devices that support more than | 8 SCSI IDs | | Table 8-XX: RESERVE(10) Command | |============================================================================= | Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | |============================================================================= |0 | Operation Code (16h) | |----+--------------------------+--------+--------------------------+--------+ |1 | Logical Unit Number | 3rdPty | Reserved | Extent | |----+--------------------------+--------+--------------------------+--------+ |2 | Reservation Identification | |----+-----------------------------------------------------------------------+ |3 | Third Party Device ID | |----+-----------------------------------------------------------------------+ |4 | Reserved | |----+-----------------------------------------------------------------------+ |5 | Reserved | |----+-----------------------------------------------------------------------+ |6 | Reserved | |----+-----------------------------------------------------------------------+ |7 | (MSB) | |----+--- Extent List Length ---+ |8 | (LSB) | |----+-----------------------------------------------------------------------+ |9 | Control Byte | |============================================================================= Sections 9, 10, & 14 changes recommended to implement single 68 pin connector. 9.2. Commands for Direct-Access Devices. The commands for Sequential-access devices shall be as shown in Table 9-1. Table 9-1: Commands for Sequential-Access Devices ============================================================================== Operation Command Name Code Type Section ------------------------------------------------------------------------------ CHANGE DEFINITION 40h O 7.2.1 COMPARE 39h O 7.2.2 COPY 18h O 7.2.3 COPY AND VERIFY 3Ah O 7.2.4 ERASE 19h M 9.2.1 INQUIRY 12h M 7.2.5 LOAD UNLOAD 1Bh O 9.2.2 LOCATE 2Bh O 9.2.3 LOG SELECT 4Ch O 7.2.6 LOG SENSE 4Dh O 7.2.7 MODE SELECT(6) 15h M 7.2.8 MODE SELECT(10) 55h O 7.2.9 MODE SENSE(6) 1Ah M 7.2.10 MODE SENSE(10) 5Ah O 7.2.11 PREVENT/ALLOW MEDIUM REMOVAL 1Eh O 8.2.4 READ 08h M 9.2.4 READ BLOCK LIMITS 05h M 9.2.5 READ BUFFER 3Ch O 7.2.12 READ POSITION 34h O 9.2.6 READ REVERSE 0Fh O 9.2.7 RECEIVE DIAGNOSTIC RESULTS 1Ch O 7.2.13 RECOVER BUFFERED DATA 14h O 9.2.8 RELEASE UNIT (6) 17h M 9.2.9 |RELEASE UNIT (10) 57h MP 9.2.9 REQUEST SENSE 03h M 7.2.14 RESERVE UNIT (6) 16h M 9.2.10 |RESERVE UNIT (10) 56h MP 9.2.10 REWIND 01h M 9.2.11 SEND DIAGNOSTIC 1Dh M 7.2.15 SPACE 11h M 9.2.12 TEST UNIT READY 00h M 7.2.16 VERIFY 13h O 9.2.13 WRITE 0Ah M 9.2.14 WRITE BUFFER 3Bh O 7.2.17 WRITE FILEMARKS 10H M 9.2.15 ============================================================================== Key: M = Command implementation is mandatory. | MP = Command implementation is mandatory on any device that addresses | more than 8 devices. O = Command implementation is optional. The following operation codes are vendor-specific: 02h, 06h, 07h, 09h, 0Ch, 0Dh, 0Eh. All other command codes for sequential-access devices are reserved for future standardization. 9.2.9. RELEASE UNIT(6) and RELEASE UNIT(10) Commands | | Table 9-XX: RELEASE(10) Command | |============================================================================= | Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | |============================================================================= |0 | Operation Code (57h) | |----+--------------------------+--------+-----------------------------------+ |1 | Logical Unit Number | 3rdPty | Reserved | |----+--------------------------+--------+-----------------------------------+ |2 | Reserved | |----+-----------------------------------------------------------------------+ |3 | Third Party Device ID | |----+-----------------------------------------------------------------------+ |4 | Reserved | |----+-----------------------------------------------------------------------+ |5 | Reserved | |----+-----------------------------------------------------------------------+ |6 | Reserved | |----+-----------------------------------------------------------------------+ |7 | Reserved | |----+-----------------------------------------------------------------------+ |8 | Reserved | |----+-----------------------------------------------------------------------+ |9 | Control Byte | |============================================================================= 9.2.10. RESERVE UNIT(6) and RESERVE UNIT(10) Commands | | Table 9-XX: RESERVE(10) Command | |============================================================================= | Bit| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | Byte | | | | | | | | | |============================================================================= |0 | Operation Code (16h) | |----+--------------------------+--------+-----------------------------------+ |1 | Logical Unit Number | 3rdPty | Reserved | |----+--------------------------+--------+-----------------------------------+ |2 | Reserved | |----+-----------------------------------------------------------------------+ |3 | Third Party Device ID | |----+-----------------------------------------------------------------------+ |4 | Reserved | |----+-----------------------------------------------------------------------+ |5 | Reserved | |----+-----------------------------------------------------------------------+ |6 | Reserved | |----+-----------------------------------------------------------------------+ |7 | (MSB) | |----+--- Extent List Length ---+ |8 | (LSB) | |----+-----------------------------------------------------------------------+ |9 | Control Byte | |=============================================================================