..................................... ST3655 Family: ..................................... ST3285N, ST3390N ..................................... ST3550N, ST3655N ..................................... SCSI Interface Drives ..................................... Product Manual .....................................
..................................... ST3655 Family: ..................................... ST3285N, ST3390N ..................................... ST3550N, ST3655N ..................................... SCSI Interface Drives ..................................... Product Manual .....................................
© 1994 Seagate Technology, Inc. All rights reserved Publication Number: 36243-001, Rev. A 18 January 1994 Seagate®, Seagate Technology® and the Seagate logo are registered trademarks of Seagate Technology, Inc. Other product names are trademarks or registered trademarks of their owners. Seagate reserves the right to change, without notice, product offerings or specifications. No part of this publication may be reproduced in any form without written permission from Seagate Technology, Inc.
ST3655 Family SCSI Drives Product Manual, Rev. A iii Contents 1.0 Specifications summary . . . . . . . . . . . . . . . . . . . . 1 1.1 Formatted capacity . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Physical geometry . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 Functional specifications . . . . . . . . . . . . . . . . . . . 2 1.4 Physical dimensions . . . . . . . . . . . . . . . . . . . . . . 2 1.5 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.6 Acoustics . . . . . . .
iv ST3655 Family SCSI Drives Product Manual, Rev. A 2.5 Cable requirements . . . . . . . . . . . . . . . . . . . . . 19 2.6 Single-ended cable . . . . . . . . . . . . . . . . . . . . . 19 2.6.1 Fast synchronous data transfer . . . . . . . . . . . . . 19 2.7 DC power connector . . . . . . . . . . . . . . . . . . . . . 20 2.8 Terminators . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.8.1 Active termination . . . . . . . . . . . . . . . . . . . . 20 2.8.2 Passive termination . . . . . . . . . . . . .
ST3655 Family SCSI Drives Product Manual, Rev. A v 3.4.13 Mode Sense command (1AH) . . . . . . . . . . . . . 53 3.4.14 Start/Stop Unit command (1BH) . . . . . . . . . . . . 57 3.4.15 Receive Diagnostic Results command (1CH) . . . . . 58 3.4.16 Send Diagnostic command (1DH) . . . . . . . . . . . 60 3.5 Group 1 commands . . . . . . . . . . . . . . . . . . . . . 61 3.5.1 Read Capacity command (25H) . . . . . . . . . . . . 61 3.5.2 Read Extended command (28H) . . . . . . . . . . . . 63 3.5.
vi ST3655 Family SCSI Drives Product Manual, Rev. A C.6 Control Mode page (0AH) . . . . . . . . . . . . . . . . . 106 C.7 Notch page (0CH) . . . . . . . . . . . . . . . . . . . . . C.8 Cache Control page (38H) . . . . . . . . . . . . . . . . C.9 Soft ID Page (EEPROM) (3CH) . . . . . . . . . . . . . . 108 110 112 C.10 Operating page (EEPROM) (00H) . . . . . . . . . . . . Appendix D. Inquiry data . . . . . . . . . . . . . . . . . . . . 113 115 D.1 Inquiry data . . . . . . . . . . . . . . . . . . . . .
ST3655 Family SCSI Drives Product Manual, Rev. A vii Figures Figure 1. Typical startup current profile . . . . . . . . . . . . . . . . 9 Figure 2. SCSI cable connector . . . . . . . . . . . . . . . . . . . 16 Figure 3. Drive connector . . . . . . . . . . . . . . . . . . . . . . 17 Figure 4. Active termination . . . . . . . . . . . . . . . . . . . . . 21 Figure 5. Passive termination . . . . . . . . . . . . . . . . . . . . 21 Figure 6. Configuration jumpers, back view . . . . . . . . . . . . . 24 Figure 7.
ST3655 Family SCSI Drives Product Manual, Rev. A 1 1.0 Specifications summary 1.1 Formatted capacity The capacities specified here do not include spare sectors and cylinders. The media contains one spare sector per cylinder and two spare cylinders per drive. You can change this allocation using the Format Device page (03H) discussed in Appendix C.3. ST3285N ST3390N Formatted capacity (Mbytes*) 248.62 344.
2 1.3 ST3655 Family SCSI Drives Product Manual, Rev. A Functional specifications Interface Fast SCSI-2 Zone Bit Recording method RLL (1,7) External data transfer rate (Mbytes per sec, avg) 5.0 asynchronous 10.0 synchronous Internal data transfer rate (Mbits per sec) 21.6 to 36.56 Spindle speed (RPM) 4,500 ± 0.5% Multisegmented cache (Kbytes) 256 Track density (TPI) 3,000* Recording density (BPI, max) 52,602 * The track density of the ST3550N is 2,400 tracks per inch. 1.
ST3655 Family SCSI Drives Product Manual, Rev. A 1.6 3 Acoustics Sound pressure is measured at idle from 1 meter above the drive top cover. Sound pressure, typ 34 dBA Sound pressure, max 38 dBA 1.7 Seek time All seek time measurements are under nominal conditions of temperature and voltage with the drive mounted horizontally. In the table below: • Track-to-track seek time is the average of all possible single-track seeks in both directions.
4 ST3655 Family SCSI Drives Product Manual, Rev. A You can pre-empt the automatic compensation by issuing a Rezero Unit command (01H). The drive performs the thermal calibration and then sets a timer and waits 2 minutes before performing the calibration again. Thermal compensation increases the execution time of the command during which it is performed by 100 msec (typ) to 350 msec (max). 1.8 Environmental This section specifies acceptable environmental conditions for the drive.
ST3655 Family SCSI Drives Product Manual, Rev. A 1.9 5 Shock and vibration All shock and vibration specifications assume that the drive is mounted in a recommended mounting configuration, as shown in Figure 9 on page 29. Inputs are measured at the drive mounting screws. Shock measurements are based on an 11 msec, half sine wave shock pulse, not to be repeated more than twice per second. Operating Nonoperating Shock 2 Gs 75 Gs 5–22 Hz vibration 0.020-inch displacement 0.
6 ST3655 Family SCSI Drives Product Manual, Rev. A b. If a jumper is installed on pins 3 and 4 of the options jumper block, the remote start option is enabled. The drive begins to spin up when the host commands the motor to start. 3. Within 250 msec after power is applied, the drive responds to the Test Unit Ready, Request Sense and Inquiry commands. 4. The drive begins to lock in speed control circuits. 5. The actuator-lock solenoid releases the actuator, producing an audible sound. 6.
ST3655 Family SCSI Drives Product Manual, Rev. A 7 1.11 DC power Except during the write procedure, you can apply power to the drive or remove power from the drive in any sequence without losing data or damaging the drive. If you remove the power from the drive during the write procedure, you may lose the data currently being written. 1.11.
8 ST3655 Family SCSI Drives Product Manual, Rev. A • Idle. The drive spindle motor is up to speed and the servo electronics are active. The heads are on track, ready to accept and execute any command without delay. The read/write electronics are powered down. The drive can enter this mode from any other mode (except the Standby mode). • Standby. This mode is not implemented. 1.11.3 Power consumption In the table below, the measurements are made at the drive power connector with an RMS DC ammeter.
ST3655 Family SCSI Drives Product Manual, Rev. A 9 amps 2.0 T2 1.7 T5 T3 T7 1.0 T4 T6 T8 T1 0 0 1 2 3 4 5 6 7 8 Seconds Figure 1. Typical startup current profile T1 Voltage is applied to the drive. T2 After a delay, the startup current is applied and the spindle begins to turn. T3 The accelerating current is applied, causing the spindle speed to increase. T4 The spindle speed is close to the final, correct value. The drive begins to lock in speed-control circuits.
10 ST3655 Family SCSI Drives Product Manual, Rev. A 1.12 Agency listings This drive is listed by agencies as follows: • Recognized in accordance with UL 478 and UL 1950 • Certified to CSA C22.2 No. 220-M1986 and CSA C22.2 No. 950 • Certified to VDE 0805/05.90 and EN 60950/1.88 as tested by VDE 1.13 FCC verification ST3655 family drives are intended to be contained solely within a personal computer or similar enclosure (not attached to an external device).
ST3655 Family SCSI Drives Product Manual, Rev. A 11 If necessary, you should consult your dealer or an experienced radio/television technician for additional suggestions. You may find helpful the following booklet prepared by the Federal Communications Commission: How to Identify and Resolve Radio-Television Interference Problems. This booklet is available from the Superintendent of Documents, US Government Printing Office, Washington, DC 20402. Refer to publication number 004-000-00345-4. Note.
ST3655 Family SCSI Drives Product Manual, Rev. A 13 2.0 Hardware and interface The SCSI-2 interface consists of a 9-bit bidirectional bus (8 data bits and 1 parity bit) plus 9 control signals supporting multiple initiators, disconnect and reconnect, and self-configuring host software. Logical block addressing is used.
14 ST3655 Family SCSI Drives Product Manual, Rev. A • Do not touch the connector pins or the printed circuit board. Do not touch the printed circuit cable between the circuit board and the head/disc assembly. • Avoid wool or synthetic clothing, carpeting, plastics and Styrofoam; these items cause static discharge. • Do not remove the factory-installed labels from the drive or cover them with additional labels. If you do, you may void the warranty.
ST3655 Family SCSI Drives Product Manual, Rev. A 2.4 15 SCSI connector You can daisy-chain the drive with a maximum of seven other SCSI devices (including the host) that have single-ended drivers and receivers using a common cable. SCSI ID 7, by convention, is usually used for the host adapter. No drive can have the same SCSI ID as the host adapter. All signals are common between all SCSI devices.
16 ST3655 Family SCSI Drives Product Manual, Rev. A In Figure 2, units are shown in inches (mm). 2.680 ± 0.015 (68.07 ± 0.38) Strain relief 2.520 (64.01) Triangle indicates position of pin 1 0.140 (3.55) 0.140 (3.55) 2.680 ± 0.015 (68.07 ± 0.38) Polarizing key 0.100 (2.54) 0.250 (6.35) 0.100 (2.54) Figure 2. SCSI cable connector 0.039 (0.99) 0.038 (0.
ST3655 Family SCSI Drives Product Manual, Rev. A 17 The drive connector is a nonshielded, 50-pin connector consisting of two rows of 25 pins with adjacent pins 0.100 inches apart. The connector is keyed with a slot. The connector is shown in Figure 3. 2.84 max 0.02 radius (typ) 0.26 0.310 max 0.08 0.02 radius (typ) 0.160 0.025 ± 0.002 0.015 0.100 typ 02.40 0.54 max 0.28 max 0.230 ± 0.003 0.260 0.100 0.360 Figure 3. Drive connector 0.100 0.
18 2.4.1 ST3655 Family SCSI Drives Product Manual, Rev. A SCSI connector pin assignments In the table below, a minus sign indicates active low.
ST3655 Family SCSI Drives Product Manual, Rev. A 2.5 19 Cable requirements The characteristic impedance of the cable should be between 90 ohms and 140 ohms. However, most available cables have a somewhat lower characteristic impedance. To minimize discontinuities and signal reflections, do not use cables of different impedances in the bus. Your design may require trade-offs in shielding effectiveness, the length of the interface cable, the number of loads, and the transfer rates.
20 2.7 ST3655 Family SCSI Drives Product Manual, Rev. A DC power connector The drive is equipped with a 4-pin power connector as shown in Figure 7 on page 25. 2.8 Terminators The interface is terminated with three SIP resistor modules that plug into sockets on the printed circuit board. You can order the drive in the active (default) or passive configuration, or without terminators, depending on your application. For terminator jumper configurations, see Section 2.9.
ST3655 Family SCSI Drives Product Manual, Rev. A Line driver (transmitter or transceiver) +2.85V 110 ohms 21 +2.85V 110 ohms Line receiver Flat cable pair ANSI SCSI compatible circuit ANSI SCSI compatible circuit Figure 4. Active termination 2.8.2 Passive termination All interface signals with the drive are single-ended and must be terminated with 220 ohms to +5V and 330 ohms to ground at each end of the cable. All signals use open-collector drivers or three-state drivers.
22 ST3655 Family SCSI Drives Product Manual, Rev. A 2.8.2.1 Single-ended drivers and receivers The drive uses single-ended drivers and receivers. Schematic representations of the removable terminator resistor packs are shown in Figure 4 on page 21 and Figure 5 on page 21. • Transmitter characteristics. The drive uses an ANSI SCSI-compatible, open-collector, single-ended driver. This driver is capable of sinking a current of 48 mA with a low-level output voltage of 0.4 volts. • Receiver characteristics.
ST3655 Family SCSI Drives Product Manual, Rev. A 2.9.2 23 Start/stop option When a jumper is installed on pins 3 and 4 of the options jumper block, the drive waits for a Start/Stop Unit command from the host before starting or stopping the spindle motor. 2.9.3 SCSI address Each device on the SCSI bus must have a unique SCSI ID. SCSI ID 7 is usually reserved for the SCSI host adapter. If you install only one drive, use SCSI ID 3 (the default).
24 ST3655 Family SCSI Drives Product Manual, Rev. A Terminating resistor packs (pin 1) J4. I/O connector (pin 1) J5. SCSI ID jumper block J9. Active/passive termination jumper block Ground 5 3 1 MSB Circuit board Signal 2 4 6 LSB 1 3 5 6 4 2 SCSI ID = 0 +2.85V to 110 ohms SCSI ID = 1 Power and ground to 220/330 ohms SCSI ID = 2 SCSI ID = 3 SCSI ID = 4 J6.
ST3655 Family SCSI Drives Product Manual, Rev. A J12. Options jumper block 7 5 3 1 25 J8. User-configuration jumper block 19 17 15 13 11 9 7 5 3 1 Circuit board Circuit board 8 6 4 2 Pin 1 2 3 4 5 6 7 8 Function Ground Parity enable Ground Remote start enable Clock ground External spindle sync. Remote LED – Remote LED + 20 18 16 14 12 10 8 6 4 2 Pin 1 2 3 4 5 6 7 8 9 10 11–20 Function SCSI ID bit 2 (MSB) Ground SCSI ID bit 1 Ground SCSI ID bit 0 (LSB) Ground Ext. spindle sync.
26 2.9.5 ST3655 Family SCSI Drives Product Manual, Rev. A Active/passive termination jumper block To select active termination (the default), install a jumper on pins 1 and 2 of the active/passive termination jumper block. To select passive termination, install jumpers on pins 5 and 6 and pins 2 and 4 of the active/passive termination jumper block, and change the terminating resistor packs. Caution.
ST3655 Family SCSI Drives Product Manual, Rev. A 27 The spindle-synchronization characteristics can be controlled by the Mode Select command using the RPL bits in byte 17 of the Rigid Disc Geometry page. In the default mode, all drives arbitrate during startup to see which drive will be the synchronized master. When the drives are calibrating their heads, they each check for a reference signal pulse.
28 ST3655 Family SCSI Drives Product Manual, Rev. A 2.12 Drive mounting You can mount the drive in any orientation. Follow the guidelines below appropriate to the set of mounting holes you elect to use: either bottom mounting holes or side mounting holes. Refer to Figure 9 on page 29 for the recommended mounting orientations and note the choice of screw holes shown. Refer to Figure 10 on page 30 for drive dimensions. Caution.
ST3655 Family SCSI Drives Product Manual, Rev. A Interface connector Power connector Figure 9.
30 ST3655 Family SCSI Drives Product Manual, Rev. A In the following figure, all dimensions are in inches (mm). 0.030 ± 0.010 (0.762 ± 0.254) 0.150 ± 0.010 (3.810 ± 0.254) 1.00 (25.40) max Six 6-32 UNC-2B threaded holes Max screw insertion depth: 0.13 inch 2.362 ± 0.010 (59.944 ± 0.254) 0.250 ± 0.010 (6.350 ± 0.254) 4.00 ± 0.02 (101.60 ± 0.51) 0.63 ± 0.02 (16.00 ± 0.51) 5.77 (146.56) max Optional front panel Four 6-32 UNC-2B threaded holes Max screw insertion depth: 0.20 inches Figure 10.
ST3655 Family SCSI Drives Product Manual, Rev. A 31 3.0 Command set The drive supports a subset of the Group 0 and Group 1 standard SCSI commands. The commands are described in this section. 3.1 Command descriptor block The initiator makes a request to the drive by sending a command descriptor block (CDB) to the drive. Each CDB has the following common characteristics: • Byte 0 always contains the operation code.
32 ST3655 Family SCSI Drives Product Manual, Rev. A 3.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.3 Supported commands The drive supports the commands listed below.
34 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4 3.4.1 Group 0 commands Test Unit Ready command (00H) The Test Unit Ready command verifies that the drive is ready; it is not a request for a self-test. If the drive accepts an appropriate media access command without encountering an error, it returns a good status.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.3 35 Request Sense command (03H) The Request Sense command requests that the drive transfer sense data to the initiator in the additional sense data format. The additional sense format is described in Appendix C. The sense data applies to the previous command on which a check condition status was returned.
36 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.4 Format Unit command (04H) The Format Unit command formats the disc so that all of the user-addressable data blocks can be accessed. In addition, the disc can be certified and control structures can be created for managing the disc and defects. If the specified logical unit is reserved, the Format Unit command is rejected with a reservation conflict status. Extent reservations are not supported. See Section 3.4.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.4.1 37 Types of defects The categories of flawed sectors are described below. This defect list is controlled by byte 1 of the defect list header described in Section 3.4.4.3. • When the drive is manufactured, the primary defect list (P-list) is written to the disc in an area that is not directly accessible by the user. This list of permanent defects (sometimes called the ETF list) cannot be changed.
38 ST3655 Family SCSI Drives Product Manual, Rev. A Byte 1 of CDB Bit 4 Bit 3 Bit 2–Bit 0 Fmt Cmp Data Lst Defect list format Description 0 0 X X X Default format. The initiator does not send the defect list header or D-list to the drive. The drive reallocates all sectors in the P-list and erases the Glist. 1 0 0 X X Extended format. The initiator sends a defect list header, but no D-list. Before formatting, the reassigned LBAs are merged into the grown defect list (G-list).
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.4.3 39 Defect list header and defect list The defect list, shown below, contains a 4-byte header, followed by one or more defect descriptors. Byte 1 of the defect list header determines whether the P and C defects are reallocated. Bit Byte 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 1 FOV 0 0 0 0 DPRY DCRT STPF 2–3 Defect list length 4–n Defect descriptor Byte 1 If the FOV bit is 1, the DPRY, DCRT and STPF bits are interpreted.
40 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.4.4 Defect descriptor—bytes-from-index format Defects are specified in the bytes-from-index format when the defect list format field is 100Binary. See byte 1 of the Format Unit command in Section 3.4.4. Each defect descriptor in the bytes-from-index format specifies the beginning of a single-byte defect location on the disc.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.4.5 41 Defect descriptor—physical sector format Defects are specified in the physical sector format when the defect list format field is 101Binary. See byte 1 of the Format Unit command in Section 3.4.4. Each defect descriptor for the physical sector format specifies a sector size defect location comprised of the cylinder number of the defect, the head number of the defect, and the defect sector number.
42 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.5 Reassign Blocks command (07H) When the drive receives the Reassign Blocks command, it reassigns defective logical blocks to available spare sectors. Use this command when the AWRE and ARRE bits are set to 0, which means that automatic reallocation is disabled. These bits are contained in byte 2 of the Error Recovery page, which is described in Appendix C.1. If the system supports disconnection, the drive disconnects while executing this command.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.5.1 43 Reassign blocks defect list The Reassign Blocks defect list contains a four-byte header followed by one or more defect descriptors. The length of each defect descriptor is four bytes. Bit Byte 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 2–3 Defect list length 4–n Defect descriptors Byte 1 The defect list length specifies the total length, in bytes, of the defect descriptors that follow.
44 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.6 Read command (08H) When the drive receives the Read command, it transfers data to the initiator. The Error Recovery page (01H) determines how the drive handles errors during a Read command. The Error Recover page is discussed in Appendix C.1. If there is a reservation access conflict, this command terminates with a reservation conflict status and no data is read. For more information about the reservation conflict status, see Section 3.2.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.7 45 Write command (0AH) When the drive receives the Write command, it writes the data from the initiator to the disc. The drive receives all the write data before seeking or disconnecting. The AWRE bit of the Error Recovery page (01H) determines how the drive handles bad sectors during a Write command. The Error Recover page is discussed in Appendix C.1.
46 ST3655 Family SCSI Drives Product Manual, Rev. A The transfer length specifies the number of contiguous logical blocks of data to be transferred. A transfer length of zero indicates that 256 logical blocks are to be transferred. Any other value indicates the number of logical blocks to be transferred. Byte 4 3.4.8 Seek command (0BH) When the drive receives the Seek command, it seeks the specified logical block address.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.9 47 Inquiry command (12H) When the drive receives the inquiry command, it asserts the data-in phase and sends 68 bytes of inquiry data to the initiator. When the requested inquiry data cannot be returned, a check condition status is reported. After the data has been transferred to the initiator, the drive deasserts the data-in phase.
48 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.10 Mode Select command (15H) The Mode Select command allows the initiator to change parameters stored in the mode pages. The mode pages are described in Appendix C. The drive stores four copies of each mode page: • Current values copy. This copy contains the parameter values the drive is using to control its operation.
ST3655 Family SCSI Drives Product Manual, Rev. A 49 If the drive detects invalid parameter data during the Mode Select command, the drive sends a sense key of illegal request with an additional sense code of invalid field in parameter list and no parameters are changed.
50 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.10.1 Mode Select parameter list The Mode Select parameter list contains a 4-byte header, followed by a 1-block descriptor (if any), followed by the pages of Mode Select parameters. Each block descriptor specifies the media characteristics for all or part of a logical unit. The rest of the Mode Select parameters are grouped by function and organized into mode pages. The mode pages are described in Appendix A.
ST3655 Family SCSI Drives Product Manual, Rev. A 51 3.4.11 Reserve command (16H) When the initiator issues a Reserve command, it requests that the drive be reserved for exclusive use by the initiator until the reservation is: • Superseded by another Reserve command from the initiator that made the reservation. An initiator that has already reserved the drive can modify that reservation by issuing another Reserve command.
52 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.12 Release command (17H) When an initiator that had reserved the drive using the Reserve command issues the Release command, it cancels the reservation. If the drive is not currently reserved and it receives a Release command, the drive returns a good status.
ST3655 Family SCSI Drives Product Manual, Rev. A 53 3.4.13 Mode Sense command (1AH) When the initiator sends this command to the drive, it returns mode page parameters to the initiator. This command is used in conjunction with the Mode Select command.
54 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.13.1 Page code and allocation length The Mode Sense command descriptor block contains a page code (byte 2, bits 5–0) and an allocation length (byte 4). These parameters are described in the following table.
ST3655 Family SCSI Drives Product Manual, Rev.
56 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.13.2 Mode sense data The Mode Sense parameter list contains a 4-byte header followed by a 8-byte block descriptor (if any), followed by the mode pages. The header and block descriptor are shown below. The mode pages are described in Appendix C.
ST3655 Family SCSI Drives Product Manual, Rev. A 57 3.4.14 Start/Stop Unit command (1BH) When the drive receives the Start/Stop Unit command, the drive either spins up or spins down, depending on the setting of the start bit in byte 4. If the host adapter supports disconnection, the drive disconnects when it receives the Start/Stop Unit command and reconnects when it is up to speed and ready.
58 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.15 Receive Diagnostic Results command (1CH) When the drive receives the Receive Diagnostics command, it sends eight diagnostic data bytes to the initiator. The initiator sends the Receive Diagnostic Results command after the drive completes the Send Diagnostic command, which is discussed in Section 3.4.16.
ST3655 Family SCSI Drives Product Manual, Rev. A 59 3.4.15.2 Diagnostic error codes The following diagnostic error codes are reported in byte 7 of the diagnostic data format in Section 3.4.15.1.
60 ST3655 Family SCSI Drives Product Manual, Rev. A 3.4.16 Send Diagnostic command (1DH) When the drive receives this command, it performs diagnostic tests on itself. In systems that support disconnection, the drive disconnects while executing this command.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.5 61 Group 1 commands 3.5.1 Read Capacity command (25H) The initiator uses the Read Capacity command to determine the capacity of the drive. When the drive receives the Read Capacity command, it sends the initiator read capacity data, which is described in Section 3.5.1.1.
62 ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.1.1 Read Capacity data The Read Capacity data is shown below. Bit Byte 7 6 5 4 3 2 0–3 Logical block address 4–7 Block length (00000200H) 1 0 Bytes 0–3 The logical block address is determined by the PMI bit in the CDB of the Read Capacity command. The PMI bit is described in Section 3.5.1. Bytes 4–7 The block length is always 512.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.2 63 Read Extended command (28H) When the drive receives the Read Extended command, it transfers data to the initiator. This command is the same as the Read command discussed in Section 3.4.6, except that in the CDB for the Read Extended command, a 4-byte logical block address and a 2-byte transfer length can be specified. If there is a reservation access conflict, this command terminates with a reservation conflict status and no data is read.
64 ST3655 Family SCSI Drives Product Manual, Rev. A Bytes 7–8 3.5.3 The transfer length specifies the number of contiguous logical blocks of data to be transferred. A transfer length of 0 means that no logical blocks are to be transferred. This condition is not considered an error. Any other value indicates the number of logical blocks to be transferred. Write Extended command (2AH) When the drive receives the Write Extended command, the drive writes the data from the initiator to the disc.
ST3655 Family SCSI Drives Product Manual, Rev. A 65 Bytes 2–5 The logical block address specifies the logical block where the write operation begins. Bytes 7–8 The transfer length specifies the number of contiguous logical blocks of data to be transferred. A transfer length of zero means that no logical blocks are to be transferred. Any other value indicates the number of logical blocks to be transferred. 3.5.
66 ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.5 Write and Verify command (2EH) When the drive receives the Write and Verify command, it writes the data sent by the initiator to the media and then verifies that the data is correctly written. If the host adapter supports disconnection, the drive disconnects while it is executing this command.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.6 67 Verify command (2FH) When the drive receives the Verify command, it verifies the data on the disc. If the host adapter supports disconnection, the drive disconnects while it is executing this command.
68 ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.7 Read Defect Data command (37H) When the drive receives this command, it reads the defect data off its reserved cylinders and transfers the defect data to the initiator. The initiator can use this command to do a Format Unit command. It reads the defect lists off the reserved cylinders and resends the lists as defect data without changing them. The Read Defect Data command can be used to access two types of defect lists, the P-list and the G-list.
ST3655 Family SCSI Drives Product Manual, Rev. A 69 allocation length bytes have been transferred or when all available defect data has been transferred to the initiator, whichever is less. 3.5.7.1 Defect list header The defect data always begins with a 4-byte header, followed by a 6-byte descriptor for each defect. The defect list header format is described below.
70 ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.8 Write Buffer command (3BH) In conjunction with the Read Buffer command, the Write Buffer command can be used in the following ways: • To diagnose problems in the drive’s data buffer. • To test the integrity of the SCSI bus. The Write Buffer command can also be used to download microcode to the buffer and save it on the disc. Note. This command treats the buffer as a single segment, regardless of the number of segments specified in Mode Page 08H.
ST3655 Family SCSI Drives Product Manual, Rev. A 71 Byte 3–5 The buffer offset is added to the starting address of the buffer to determine the destination of the first data byte. The bytes that follow are placed in sequential addresses. If the sum of the buffer offset and the transfer length exceeds the buffer size reported by the Read Buffer command (see Section 3.5.9), the drive generates a check condition status and the initiator does not transfer any data.
72 ST3655 Family SCSI Drives Product Manual, Rev. A Byte 3–5 The buffer offset is added to the starting address of the buffer to determine the source of the first data byte. The bytes that follow are read from sequential addresses. If the sum of the buffer offset and the transfer length exceeds the available length reported in the Read Buffer header (see Section 3.5.9.1), the drive transfers all the data contained in the buffer.
ST3655 Family SCSI Drives Product Manual, Rev. A 73 3.5.10 Read Long command (3EH) When the drive receives the Read Long command, it transfers data to the initiator. Bit Byte 7 6 5 4 3 2 1 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 Flag Link 1 LUN 2–5 6 Logical block address 0 0 0 7–8 9 0 0 Byte transfer length 0 0 0 0 0 Bytes 2–5 The logical block address specifies the LBA where the drive begins reading data.
74 ST3655 Family SCSI Drives Product Manual, Rev. A 3.5.11 Write Long command (3FH) When the drive receives the Write Long command, it writes one logical block of data and six bytes of error correction code (ECC) to the disc. During this command, the drive does not perform any ECC verification.
ST3655 Family SCSI Drives Product Manual, Rev. A 3.6 75 Group 2, 3 and 4 commands Group 2, 3 and 4 commands are 10-byte commands. Group 2 commands are are not implemented. Group 3 and 4 commands are reserved. If the drive receives one of these commands, it returns a check condition status. Note. Do not use Group 3 and 4 commands. If you do, you may destroy data on the disc. 3.7 Group 5 and 6 commands Group 5 and 6 commands are 12-byte commands. Group 5 commands are not implemented.
ST3655 Family SCSI Drives Product Manual, Rev. A 77 Appendix A. Supported messages A.1 Single-byte messages The implemented single-byte messages are listed below.
78 ST3655 Family SCSI Drives Product Manual, Rev. A A.2 Synchronous data transfer request message (01H) The synchronous data transfer message is the only extended message supported by the drive. Depending on the value contained in the SSM bit (contained in byte 2 of the Operating page in Section C.10), the drive or the initiator can negotiate for synchronous data transfer after a reset.
ST3655 Family SCSI Drives Product Manual, Rev. A 79 Appendix B. Sense data The appendix contains the descriptions for sense data returned by the Request Sense command. For more information on the Request Sense command, see Section 3.4.3. B.1 Additional sense data When the initiator issues a Request Sense command, the drive returns the following additional sense data.
80 Byte 2 ST3655 Family SCSI Drives Product Manual, Rev. A If the incorrect length indicator (ILI) bit is zero, the requested block of data from the previous command did not match the logical block length of the data on the disc. If the ILI bit is one, the request block of data from the previous command matched the logical block length of the data on the disc. The sense key indicates one of nine general error categories. These error categories are listed in Appendix B.2.
ST3655 Family SCSI Drives Product Manual, Rev. A 81 B.2 Sense key The sense keys in the lower-order bits of byte 2 of the sense data returned by the Request Sense command are described in the following table. You can find a more detailed description of the error by checking the additional sense code and the additional sense code qualifier in Section B.3. Sense key Description 0H No Sense. In the case of a successful command, no specific sense key information needs to be reported for the drive.
82 ST3655 Family SCSI Drives Product Manual, Rev. A B.3 Additional sense code and additional sense code qualifier The additional sense code and additional sense code qualifiers returned in byte 12 and byte 13, respectively, of the Sense Data Format of the Request Sense command are listed in the following table. Error code (hex) Description Byte 12 Byte 13 00 00 No additional information is supplied. 01 00 There is no index/sector signal. 02 00 There is no seek complete signal.
ST3655 Family SCSI Drives Product Manual, Rev. A Error code (hex) 83 Description Byte 12 Byte 13 11 00 An unrecovered read error occurred. 11 01 The read retries were exhausted. 11 02 The error was too long to correct. 11 03 There were multiple read errors. 11 04 A read error occurred. Auto-reallocation was attempted, but it failed. 12 00 The address mark was not found in the ID field. 13 00 The address mark was not found in the data field. 14 00 No record was found.
84 ST3655 Family SCSI Drives Product Manual, Rev. A Error code (hex) Description Byte 12 Byte 13 19 01 The defect list is not available. 19 02 There is an error in the primary defect list. 19 03 There is an error in the grown defect list. 1A 00 A parameter overrun occurred. 1B 00 A synchronous transfer error occurred. 1C 00 The defect list could not be found. 1C 01 The primary defect list could not be found. 1C 02 The grown defect list could not be found.
ST3655 Family SCSI Drives Product Manual, Rev. A Error code (hex) 85 Description Byte 12 Byte 13 2A 00 Some parameters were changed by another initiator. 2A 01 The Mode Select parameters were changed by another initiator. 2B 00 The microcode was downloaded. 2F 00 The tagged commands were cleared by another initiator. 30 01 The media cannot be read because the format is not recognized. 30 02 The media cannot be read because the format is incompatible with certain parameters.
86 ST3655 Family SCSI Drives Product Manual, Rev. A Error code (hex) Description Byte 12 Byte 13 40 A3 The self-test routine discovered a SCSI protocol error. 40 A4 The self-test routine discovered a DMA error. 40 A5 The self-test routine discovered an error in the disc sequencer. 40 A6 The self-test routine discovered an error in the disc sequencer RAM. 40 A7 A self-test error occurred. 40 A8 The EEPROM cannot be read or written.
ST3655 Family SCSI Drives Product Manual, Rev. A Error code (hex) 87 Description Byte 12 Byte 13 40 C1 A failure occurred while the grown defect list was being written. 40 C2 The write life-cycle of the EEPROM has been exceeded. 40 C3 There was an attempt to add an illegal entry to the grown defect list. 40 C4 There was an attempt to add a duplicate entry to the grown defect list. 41 00 A data path diagnostic failed. 42 00 A power-on or self-test failure occurred.
ST3655 Family SCSI Drives Product Manual, Rev. A 89 Appendix C. Mode pages Mode pages are groups of parameters stored by the drive. These parameters can be read using the Mode Sense command and changed using the Mode Select command. These commands are described in Sections 3.4.10 and 3.4.13. This appendix contains the default parameters and the changeable parameters for the mode pages. The current parameters and the saved parameters are not shown. Note.
90 ST3655 Family SCSI Drives Product Manual, Rev. A For all mode pages: • If the changeable value is 0, the initiator cannot change the bit directly. If the changeable value is 1, the initiator can change the bit directly. For example, in the header below, the changeable value for the page code bits is 0, which means that the page code cannot be changed; the changeable value of the PS bit is one, which means that the PS bit can be changed.
ST3655 Family SCSI Drives Product Manual, Rev. A 91 C.1 Error Recovery page (01H) The Error Recovery page is shown below. This table summarizes the function, the default value, and the changeability of each bit.
92 ST3655 Family SCSI Drives Product Manual, Rev. A Byte 2 When the Automatic Read Reallocation Enabled (ARRE) continued bit is 1, the drive automatically reallocates bad blocks detected while reading from the disc. When the ARRE bit is 0, the drive does not automatically reallocate bad blocks. Instead, a check condition status is reported with a sense key of media error. When the Transfer Block (TB) bit is 1, the failing data block is transferred to the initiator.
ST3655 Family SCSI Drives Product Manual, Rev. A 93 Byte 5 The head offset count is not implemented. Head offsets are performed as part of the drive’s retry algorithms. Byte 6 The data strobe offset count is not implemented. Byte 7 Reserved. Byte 8 The write retry count field contains the maximum number of times the drive attempts its recovery algorithms. If the EER bit is set, the number of retries specified by the retry count, up to a maximum of nine retries, is performed before ECC is applied.
94 ST3655 Family SCSI Drives Product Manual, Rev. A Byte 2 The buffer full ratio field indicates, on Read commands, how full the drive’s buffer is before reconnecting. The drive rounds up to the nearest whole logical block. This parameter is the numerator of a fraction that has 256 as its denominator. Byte 3 The buffer empty ratio field indicates, on Write commands, how empty the drive’s buffer is before reconnecting to fetch more data. The drive rounds up to the nearest whole logical block.
ST3655 Family SCSI Drives Product Manual, Rev. A 95 C.3 Format Device page (03H) The Format Device page is shown below. This table summarizes the function, the default value, and the changeability of each bit. This page is sent only before the Format Unit command is sent. The drive parameters are updated immediately, but any changes between these current parameters and the existing media format do not take effect until after the Format Unit command is completed.
96 ST3655 Family SCSI Drives Product Manual, Rev. A continued from previous page Bit Byte 7 20 6 5 4 3 SSEC HSEC RMB SURF default 1 0 0 0 changeable 0 0 0 0 2 1 0 Reserved 0 0 21–23 (default) Reserved (000000H) changeable 000000H 0 0 Bytes 2–3 The tracks per zone field indicates the number of tracks the drive allocates to each defect-management zone. Spare sectors or tracks are placed at the end of each defect management zone.
ST3655 Family SCSI Drives Product Manual, Rev. A 97 Bytes 10–11 The sectors per track field indicates the number of physical sectors the drive allocates per track. The drive reports the average number of physical sectors per track since the number of sectors per track varies between the outer and inner tracks. Bytes 12–13 The data bytes per physical sector field indicates the number of data bytes allocated per physical sector.
98 Byte 20 ST3655 Family SCSI Drives Product Manual, Rev. A The drive type field bits are defined as follows: The Soft Sectoring (SSEC) bit is set to 1. This bit is reported as not changeable. Although it can be set to satisfy system requirements, it does not affect drive performance. The Hard Sectoring (HSEC) bit is set to 0. This bit is reported as not changeable. Although it can be set to satisfy system requirements, it does not affect drive performance.
ST3655 Family SCSI Drives Product Manual, Rev. A 99 C.4 Rigid Disc Geometry page (04H) The Rigid Disc Geometry page is shown below. This table summarizes the function, the default value, and the changeability of each bit.
100 ST3655 Family SCSI Drives Product Manual, Rev. A Bytes 2–4 The number of cylinders field specifies the number of user-accessible cylinders, including two spare cylinders set aside for defects. The drive uses the additional cylinders for storing parameters and defect lists, or for diagnostic purposes. The number of cylinders is specified on page 1. Byte 5 The number of heads field specifies the number of read/write heads on the drive. The number of heads is specified on page 1.
ST3655 Family SCSI Drives Product Manual, Rev. A 101 C.5 Caching page (08H) The drive uses read look-ahead, read caching and write caching to improve seek times and performance. C.5.1 Read look-ahead and read caching The drive uses an algorithm that improves seek performance by reading the next logical sectors after the last requested sector. These unrequested sectors are read into a buffer and are ready to be transmitted to the host before they are requested.
102 ST3655 Family SCSI Drives Product Manual, Rev. A C.5.2 Write caching and write merging Write caching. The drive uses the write segment to store write commands and data. After the drive caches the commands and data, it is immediately ready to process new commands. The drive writes the data to the disc at its next convenient opportunity. Write merging. The drive accepts contiguous write commands and executes them sequentially as one command. C.5.
ST3655 Family SCSI Drives Product Manual, Rev.
104 Byte 2 continued ST3655 Family SCSI Drives Product Manual, Rev. A When the Multiplication Factor (MF) bit is 0, the drive interprets the minimum prefetch and maximum prefetch fields as the number of logical blocks to be prefetched. When the MF bit is 1, the drive interprets the minimum prefetch and maximum prefetch fields in terms of a number which, when multiplied by the transfer length of the current command, yields the number of logical blocks to be prefetched.
ST3655 Family SCSI Drives Product Manual, Rev. A 105 When the Disable Read-Ahead (DRA) bit is 1, the drive does not read into the buffer any logical blocks beyond the addressed logical blocks. When the DRA bit equals 0, the drive can continue reading logical blocks into the buffer beyond the addressed logical blocks. Byte 13 The number of cache segments field determines how many segments into which the cache should be divided. Valid values are 1, 2, 4, 8, 16 and 32.
106 ST3655 Family SCSI Drives Product Manual, Rev. A C.6 Control Mode page (0AH) The Control Mode page is shown below. This table summarizes the function, the default value, and the changeability of each bit.
ST3655 Family SCSI Drives Product Manual, Rev. A Bytes 8–9 107 The busy timeout period field contains the maximum possible value, which means that the drive can remain busy an unlimited amount of time. Bytes 10–11 Reserved.
108 ST3655 Family SCSI Drives Product Manual, Rev. A C.7 Notch page (0CH) The Notch page contains parameters that describe the notches. The table below summarizes the function, default value, and the changeability of each bit. The drive uses zone bit recording, which means that the outer cylinders of the disc contain more logical blocks than the inner cylinders. The cylinders are organized into groups, called zones or notches. Every logical block is part of a notch. Notches do not overlap.
ST3655 Family SCSI Drives Product Manual, Rev. A Byte 2 109 The notched drive (ND) bit is always 1, which means the disc contains notches of different recording densities. For each supported active notch value, this page defines the starting and ending boundaries of the notch. The logical or physical notch (LPN) bit is 0, which means the notch boundaries are based on the physical parameters of the logical unit. The cylinder is most significant; the head is least significant. Byte 3 Reserved.
110 ST3655 Family SCSI Drives Product Manual, Rev. A C.8 Cache Control page (38H) The Cache Control page is shown below. This table summarizes the function, the default value and the changeability of each bit.
ST3655 Family SCSI Drives Product Manual, Rev. A 111 Byte 5 The maximum prefetch multiplier field always contains the same value as byte 9 of the Caching page. The initiator cannot directly change this byte. Byte 6 The minimum prefetch field always contains the same value as byte 7 of the Caching page. The initiator cannot directly change this byte. Byte 7 The minimum prefetch multiplier field always contains the same value as byte 7 of the Caching page.
112 ST3655 Family SCSI Drives Product Manual, Rev. A C.9 Soft ID Page (EEPROM) (3CH) The Soft ID page is shown below. This table summarizes the function, the default value and the changeability of each bit. This page is saved in an EEPROM that has a life span of 10,000 writes. Note. The write life span is 10,000 writes. To preserve the write life span of the EEPROM, the page is not saved to the EEPROM during a Mode Select command if the new parameters are the same as the current contents in the EEPROM.
ST3655 Family SCSI Drives Product Manual, Rev. A 113 When the param enable bit is 0, the drive does not check parity. When the param enable bit is 1, the drive checks parity. This bit is only valid if the soft parity bit is 1. C.10 Operating page (EEPROM) (00H) The Operating page is shown in the table below. This table shows the function, the default value, and the changeability of each bit. The drive accepts an Operating page of two lengths: two bytes or three bytes.
114 ST3655 Family SCSI Drives Product Manual, Rev. A Appendix B.3. When the usage bit is 0, the warning message is disabled. If requested, the EEPROM data and the write counter is updated even after the write life span is exceeded, but the integrity of the data cannot be assured. Byte 2 When the synchronous select mode (SSM) bit is 0, the drive does not send a synchronous data transfer message unless the initiator has already issued a synchronous data transfer message.
ST3655 Family SCSI Drives Product Manual, Rev. A 115 Appendix D. Inquiry data When the initiator issues an Inquiry command, the drive returns either of the following two types of data, depending on the value in the EVPD bit in byte 1 of the Inquiry command descriptor block: • Inquiry data • Vital product data Both types of data are discussed in this appendix. The Inquiry command is described in Section 3.4.9. D.
116 Byte 0 ST3655 Family SCSI Drives Product Manual, Rev. A The peripheral qualifier field contains zero, which means that the drive is currently connected to the logical unit that is issuing the Inquiry command. The peripheral device type field contains zero, which means that the drive is a direct access device. Byte 1 The RMB bit is 0, which means the discs are not removable. The device type modifier is not used.
ST3655 Family SCSI Drives Product Manual, Rev. A 117 The CmdQue bit is one, which means that the drive supports tagged command queuing. The Soft Re bit is zero, which means that the drive responds to a reset with a hard reset. Bytes 8–15 The vendor identification field contains “Seagate” in ASCII text. Bytes 16–31 The product identification field contains the model number of the drive in ASCII text.
118 ST3655 Family SCSI Drives Product Manual, Rev. A D.2 Vital product data pages When the initiator issues an Inquiry command, and the EVPD bit in byte 1 of the Inquiry command descriptor block is 1, the drive returns vital product data pages. If the EVDP bit in byte 1 of the Inquiry command descriptor block is 0, see Appendix D.1. All vital product data pages contain a 4-byte header, shown below.
ST3655 Family SCSI Drives Product Manual, Rev. A 119 D.2.1 Unit Serial Number page (80H) The Unit Serial Number page is shown below. The table summarizes the function and the default value of each bit. Bit Byte 0 7 6 5 Peripheral qualifier 4 3 2 1 0 Peripheral device type 1 Page code (80H) 2 Reserved (00H) 3 Page length (0EH) 4–17 Product serial number Bytes 4–17 The product serial number field contains the serial number for the drive in ASCII.
120 ST3655 Family SCSI Drives Product Manual, Rev. A D.2.2 Implemented Operating Definition page (81H) The Implemented Operating Definition page is shown below. The table summarizes the function and the default value of each bit.
ST3655 Family SCSI Drives Product Manual, Rev. A 121 D.2.3 Firmware Numbers page (C0H) The Firmware Numbers page is shown below. The table summarizes the function, and default value of each bit.
122 ST3655 Family SCSI Drives Product Manual, Rev. A D.2.4 Date Code page (C1H) The Date Code page is shown below. The table summarizes the function and the default value of each bit. Bit Byte 7 0 6 5 4 3 Peripheral qualifier 2 1 0 Peripheral device type 1 Page code (C1H) 2 Reserved (00H) 3 Page length (03H) 4 Year 5–6 Week Bytes 4 The year field contains the year, in ASCII, that the firmware was released.
ST3655 Family SCSI Drives Product Manual, Rev. A 123 Appendix E. Timing diagrams 0 –DB(7–0,P) 1 Initiator ID Init. and target ID First byte 0 –ATN 1 0 –SEL 1 0 –BUSY 1 0 –I/O 1 0 –MSG 1 0 –C/D 1 0 –REQ 1 0 –ACK 1 T01 T02 Figure 11.
124 ST3655 Family SCSI Drives Product Manual, Rev. A 0 –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK 1 Initiator ID Identify message Init. and target ID 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T01 T03 T33 Figure 12. Arbitration, selection (with ATN) and message out Description Symbol Typical Max Target select time (without arbitration) T00 <1.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN 0 1 Identify message 125 First byte 0 1 0 –SEL 1 0 –BUSY –I/O –MSG –C/D 1 0 1 0 1 0 1 0 –REQ –ACK 1 0 1 T04 Figure 13.
126 ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK 0 1 First byte Second byte Last byte 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T22 T23 T22 T23 Figure 14. Command descriptor block transfer Description Symbol Typical Max Command byte transfer T22 <0.08 µsec 0.15 µsec Next command byte access * T23 <6.5 µsec 1.0 µsec * T23 is used, except for byte 7 of a 10-byte CDB. A 6-byte CDB requires less than 5 µsec for five T23 occurrences.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK 0 1 Status Last byte 127 Cmd Complete 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T05 T34 T18 T32 T19 Figure 15. Command, status, command complete message and bus free Description Symbol Typical Max Command to status T05 Command dependent Status to command complete message T18 <150 µsec — Command complete message to bus free T19 <100 µsec — Message in byte transfer T32 <0.
128 ST3655 Family SCSI Drives Product Manual, Rev. A 0 –DB(7–0,P) –ATN –SEL 1 Last byte Disconnect Arb. ID 0 1 0 1 0 –BUSY –I/O 1 0 1 0 –MSG –C/D –REQ –ACK 1 0 1 0 1 0 1 T09 T10 T11 Figure 16. Last command byte, disconnect message, bus free and reselection Description Symbol Command to disconnect message T09 Disconnect message to bus free T10 Disconnect to arbitration (for reselect). Measures disconnected command overhead.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK 0 1 Target and Init. ID Target ID 129 Identify message 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T12 T13 T14 T32 Figure 17. Arbitration, reselection and message in Description Symbol Typical Max Target wins arbitration (for reselect) T12 <6 µsec — Arbitration to reselect T13 <5 µsec — Reselect to identify message in T14 <150 µsec — Message in byte transfer T32 <0.1 µsec 0.
130 –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK ST3655 Family SCSI Drives Product Manual, Rev. A 0 1 Status Identify message Cmd Complete 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T15 T34 T18 T32 T19 Figure 18.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN –SEL –BUSY –I/O 0 1 Last byte 131 First byte 0 1 0 1 0 1 0 1 0 –MSG –C/D –REQ –ACK 1 0 1 0 1 0 1 T06 Figure 19.
132 –DB(0–7,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK ST3655 Family SCSI Drives Product Manual, Rev. A 0 1 Last byte First byte 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T07, T08 Figure 20.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(0–7,P) –ATN –SEL –BUSY –I/O 0 1 Identify message 133 First byte 0 1 0 1 0 1 0 1 0 –MSG –C/D –REQ –ACK 1 0 1 0 1 0 1 T16 Figure 21.
134 –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ –ACK ST3655 Family SCSI Drives Product Manual, Rev. A 0 1 First byte Second byte Last byte 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 T24 T28 T26 T30 T24 T28 T26 T30 Figure 22. Data in block transfer Description Symbol Typical Max Data in block transfer (ASYNC) T24 <0.1 µsec 0.2 µsec Next data in byte access (ASYNC) T26 <0.8 µsec 1.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –ATN –SEL –BUSY –I/O –MSG –C/D –REQ 0 1 Second byte First byte 135 Last byte 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 –ACK 1 T25 T29 T27 T31 T25 T29 T27 T31 Figure 23. Data out block transfer Description Symbol Typical Max Data out block transfer (ASYNC) T25 <0.1 µsec 0.2 µsec Next data out byte access (ASYNC) T27 <0.8 µsec 1.
136 –DB(0–7,P) ST3655 Family SCSI Drives Product Manual, Rev. A 0 1 Last byte Save Pointer Disconnect 0 –ATN 1 0 –SEL –BUSY –I/O –MSG –C/D –REQ 1 0 1 0 1 0 1 0 1 0 1 0 –ACK 1 T20 T32 T21 T32 T10 Figure 24.
ST3655 Family SCSI Drives Product Manual, Rev. A 137 0 –DB(0–7,P) 1 Last byte Status Cmd Complete 0 –ATN 1 0 –SEL 1 0 –BUSY 1 0 –I/O 1 0 –MSG 1 0 –C/D 1 0 –REQ 1 0 –ACK 1 T17 T34 T18 T32 T19 Figure 25. Data in, status, command complete message and bus free Description Symbol Typical Max Data to status T17 Command dependent Status to command complete message T18 <150 µsec — Command complete message to bus free T19 <100 µsec — Message in byte transfer T32 <0.
138 ST3655 Family SCSI Drives Product Manual, Rev. A 0 –DB(7–0,P) 1 0 –I/O 1 0 –C/D 1 0 –MSG 1 0 –REQ 1 0 –ACK 1 T5 T1 T2 T3 T6 T4 T7 T9 T8 T10 Figure 26. Synchronous read timing Description Symbol Min I/O low to data bus enable T1 400 nsec Data bus valid to REQ– low T2 57.5 nsec REQ– assertion period T3 30.0 nsec REQ– deassertion period T4 30.0 nsec REQ– high to data hold T5 — REQ– low ACK– low T6 10 nsec ACK– assertion period T7 30.
ST3655 Family SCSI Drives Product Manual, Rev. A –DB(7–0,P) –I/O –MSG –C/D –REQ –ACK 139 0 1 0 1 0 1 0 1 0 1 0 1 T4 T2 T3 T7 T8 T1 T9 T5 T6 T10 Figure 27. Synchronous write timing Description Symbol Min Max I/O high to data bus disable T1 — 50 nsec REQ– assertion period T2 30.0 nsec — REQ– deassertion period T3 30.0 nsec — Data valid to ACK– low T4 — — ACK– assertion period T5 30.0 nsec — ACK– deassertion period T6 30.
Seagate Technology, Inc. 920 Disc Drive, Scotts Valley, California 95066, USA Publication Number: 36243-001, Rev.
