Seagate ST3655N Product manual

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ST3655 Family:
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ST3285N, ST3390N
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ST3550N, ST3655N
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SCSI Interface Drives
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Product Manual
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ST3655 Family:
.....................................
ST3285N, ST3390N
.....................................
ST3550N, ST3655N
.....................................
SCSI Interface Drives
.....................................
Product Manual
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© 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.7 Seek time . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.7.1 Read look-ahead and caching . . . . . . . . . . . . . . 3
1.7.2 Thermal compensation . . . . . . . . . . . . . . . . . . 3
1.8 Environmental . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.8.1 Ambient temperature . . . . . . . . . . . . . . . . . . . 4
1.8.2 Temperature gradient . . . . . . . . . . . . . . . . . . . 4
1.8.3 Relative humidity . . . . . . . . . . . . . . . . . . . . . 4
1.8.4 Altitude . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.9 Shock and vibration . . . . . . . . . . . . . . . . . . . . . . 5
1.10 Start and stop time . . . . . . . . . . . . . . . . . . . . . . 5
1.10.1 Power-up sequence . . . . . . . . . . . . . . . . . . . 5
1.10.2 Power-down sequence . . . . . . . . . . . . . . . . . 6
1.10.3 Auto-park . . . . . . . . . . . . . . . . . . . . . . . . 6
1.11 DC power . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.11.1 Input noise . . . . . . . . . . . . . . . . . . . . . . . . 7
1.11.2 Power management . . . . . . . . . . . . . . . . . . . 7
1.11.3 Power consumption . . . . . . . . . . . . . . . . . . . 8
1.12 Agency listings . . . . . . . . . . . . . . . . . . . . . . . 10
1.13 FCC verification . . . . . . . . . . . . . . . . . . . . . . 10
2.0 Hardware and interface . . . . . . . . . . . . . . . . . . . . 13
2.1 SCSI-2 compatibility . . . . . . . . . . . . . . . . . . . . . 13
2.2 Handling and static-discharge precautions . . . . . . . . . 13
2.3 Hot-plugging . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4 SCSI connector . . . . . . . . . . . . . . . . . . . . . . . 15
2.4.1 SCSI connector pin assignments . . . . . . . . . . . . 18
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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 . . . . . . . . . . . . . . . . . . . 21
2.9 Jumper configurations . . . . . . . . . . . . . . . . . . . . 22
2.9.1 Parity enable option . . . . . . . . . . . . . . . . . . 22
2.9.2 Start/stop option . . . . . . . . . . . . . . . . . . . . 23
2.9.3 SCSI address . . . . . . . . . . . . . . . . . . . . . . 23
2.9.4 Terminator power source jumper block . . . . . . . . . 23
2.9.5 Active/passive termination jumper block . . . . . . . . 26
2.10 Remote LED connection . . . . . . . . . . . . . . . . . . 26
2.11 External spindle synchronization option . . . . . . . . . . 26
2.12 Drive mounting . . . . . . . . . . . . . . . . . . . . . . . 28
2.12.1 Bottom mounting holes . . . . . . . . . . . . . . . . 28
2.12.2 Side mounting holes . . . . . . . . . . . . . . . . . . 28
3.0 Command set . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.1 Command descriptor block . . . . . . . . . . . . . . . . . 31
3.2 Status byte codes . . . . . . . . . . . . . . . . . . . . . . 32
3.3 Supported commands . . . . . . . . . . . . . . . . . . . . 33
3.4 Group 0 commands . . . . . . . . . . . . . . . . . . . . . 34
3.4.1 Test Unit Ready command (00H) . . . . . . . . . . . . 34
3.4.2 Rezero Unit command (01H) . . . . . . . . . . . . . . 34
3.4.3 Request Sense command (03H) . . . . . . . . . . . . 35
3.4.4 Format Unit command (04H) . . . . . . . . . . . . . . 36
3.4.5 Reassign Blocks command (07H) . . . . . . . . . . . 42
3.4.6 Read command (08H) . . . . . . . . . . . . . . . . . 44
3.4.7 Write command (0AH) . . . . . . . . . . . . . . . . . 45
3.4.8 Seek command (0BH) . . . . . . . . . . . . . . . . . 46
3.4.9 Inquiry command (12H) . . . . . . . . . . . . . . . . . 47
3.4.10 Mode Select command (15H) . . . . . . . . . . . . . 48
3.4.11 Reserve command (16H) . . . . . . . . . . . . . . . 51
3.4.12 Release command (17H) . . . . . . . . . . . . . . . 52
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
3.5.3 Write Extended command (2AH) . . . . . . . . . . . . 64
3.5.4 Seek Extended command (2BH) . . . . . . . . . . . . 65
3.5.5 Write and Verify command (2EH) . . . . . . . . . . . . 66
3.5.6 Verify command (2FH) . . . . . . . . . . . . . . . . . 67
3.5.7 Read Defect Data command (37H) . . . . . . . . . . . 68
3.5.8 Write Buffer command (3BH) . . . . . . . . . . . . . . 70
3.5.9 Read Buffer command (3CH) . . . . . . . . . . . . . . 71
3.5.10 Read Long command (3EH) . . . . . . . . . . . . . . 73
3.5.11 Write Long command (3FH) . . . . . . . . . . . . . . 74
3.6 Group 2, 3 and 4 commands . . . . . . . . . . . . . . . . 75
3.7 Group 5 and 6 commands . . . . . . . . . . . . . . . . . 75
3.8 Group 7 commands . . . . . . . . . . . . . . . . . . . . . 75
Appendix A. Supported messages . . . . . . . . . . . . . . . . 77
A.1 Single-byte messages . . . . . . . . . . . . . . . . . . . . 77
A.2 Synchronous data transfer request message (01H) . . . . . 78
Appendix B. Sense data . . . . . . . . . . . . . . . . . . . . . . 79
B.1 Additional sense data . . . . . . . . . . . . . . . . . . . . 79
B.2 Sense key . . . . . . . . . . . . . . . . . . . . . . . . . . 81
B.3 Additional sense code and additional sense code qualifier . 82
Appendix C. Mode pages . . . . . . . . . . . . . . . . . . . . . 89
C.1 Error Recovery page (01H) . . . . . . . . . . . . . . . . . 91
C.2 Disconnect/Reconnect page (02H) . . . . . . . . . . . . . 93
C.3 Format Device page (03H) . . . . . . . . . . . . . . . . . 95
C.4 Rigid Disc Geometry page (04H) . . . . . . . . . . . . . . 99
C.5 Caching page (08H) . . . . . . . . . . . . . . . . . . . . 101
C.5.1 Read look-ahead and read caching . . . . . . . . .
101
C.5.2 Write caching and write merging . . . . . . . . . . .
C.5.3 Caching page description . . . . . . . . . . . . . .
102
102
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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 . . . . . . . . . . . . . . . . . . . . . . . .
D.2 Vital product data pages . . . . . . . . . . . . . . . . .
115
118
D.2.1 Unit Serial Number page (80H) . . . . . . . . . . . .
D.2.2 Implemented Operating Definition page (81H) . . . .
D.2.3 Firmware Numbers page (C0H) . . . . . . . . . . .
119
120
121
D.2.4 Date Code page (C1H) . . . . . . . . . . . . . . . .
D.2.5 Jumper Settings page (C2H) . . . . . . . . . . . . .
Appendix E. Timing diagrams . . . . . . . . . . . . . . . . . .
122
122
123
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. Configuration jumpers, front view . . . . . . . . . . . . . 25
Figure 8. External spindle clock timing diagram . . . . . . . . . . . 27
Figure 9. Drive mounting orientations . . . . . . . . . . . . . . . . 29
Figure 10. Drive mounting dimensions . . . . . . . . . . . . . . . 30
Figure 11. Arbitration, selection (without ATN) and command . .
123
Figure 12. Arbitration, selection (with ATN) and message out . .
124
Figure 13. Identify message out to command . . . . . . . . . . .
125
Figure 14. Command descriptor block transfer . . . . . . . . . .
126
Figure 15. Command, status, command complete message
and bus free . . . . . . . . . . . . . . . . . . . .
Figure 16. Last command byte, disconnect message, bus free
and reselection . . . . . . . . . . . . . . . . . .
Figure 17. Arbitration, reselection and message in . . . . . .
Figure 18. Reselection, status, command complete
and bus free . . . . . . . . . . . . . . . . . . . .
. . . 127
. . . 128
. . . 129
. . . 130
Figure 19. Last command byte to data in . . . . . . . . . . . . . . 131
Figure 20. Last command byte to data out . . . . . . . . . . . . . 132
Figure 21. Reselect identify message to data in . . . . . . . . . . 133
Figure 22. Data in block transfer . . . . . . . . . . . . . . . . . . 134
Figure 23. Data out block transfer . . . . . . . . . . . . . . . . . . 135
Figure 24. Last data byte, save pointer message and
disconnect message . . . . . . . . . . . . . . . . . . . 136
Figure 25. Data in, status, command complete message
and bus free . . . . . . . . . . . . . . . . . . . . . . . 137
Figure 26. Synchronous read timing . . . . . . . . . . . . . . . . 138
Figure 27. Synchronous write timing . . . . . . . . . . . . . . . . 139
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
344.31
Bytes per sector
512
512
Total sectors
485,601
672,480
ST3550N
ST3655N
Formatted capacity (Mbytes*)
456.48
545.29
Bytes per sector
512
512
Total sectors
891,574
1,065,036
* One megabyte equals one million bytes.
1.2
Physical geometry
ST3285N
ST3390N
Discs
2
2
Servo heads
1
1
Read/write heads
3
3
Cylinders
1,777
2,676
ST3550N
ST3655N
Discs
3
3
Servo heads
1
1
Read/write heads
5
5
Cylinders
2,126
2,493
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.
1.4
Physical dimensions
Height (max)
1.00 inch (25.4 mm)
Width (max)
4.02 inches (102.1 mm)
Depth (max)
5.77 inches (146.6 mm)
Weight (max)
1.5 lb (0.68 Kg)
1.5
Reliability
Read error rates are measured with automatic retries and data correction
with ECC enabled and all flaws reallocated. MTBF is measured at
nominal power at sea level and 40°C ambient temperature.
Nonrecoverable read errors
1 per 1013 bits transferred
Seek errors
1 per 107 physical seeks
MTBF
250,000 power-on hours
Service life
5 years
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.
• Average seek time is a true statistical random average of at least 5,000
measurements of seeks in both directions between random cylinders,
less overhead.
• Full-stroke seek time is one-half the time needed to seek from logical
block address zero (LBA 0) to the maximum LBA and back to LBA 0.
Track-to-track
seek time
Average
seek time
Full-stroke
seek time
Average
latency
3.5 msec typ
4.0 msec max
12.0 msec typ
14.0 msec max
30.0 msec typ
32.0 msec max
6.67 msec
Note. Host overhead varies between systems and cannot be specified.
Drive internal overhead is measured by issuing a no-motion seek.
Drive overhead is typically less than 1.0 msec.
1.7.1
Read look-ahead and caching
The drive uses algorithms that improve seek performance by storing data
in a buffer and processing it at a more convenient time. Three methods
are employed: read look-ahead, read caching and write caching. These
are described in Appendix C.5.
1.7.2
Thermal compensation
The thermal compensation feature compensates for position offset of the
selected head due to variations in temperature. The drive automatically
performs thermal compensation during startup and every 2 minutes
thereafter.
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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.
The operating specifications assume that the drive is powered up. The
nonoperating specifications assume that the drive is packaged as it was
shipped from the factory.
1.8.1
Ambient temperature
Operating
5°C to 55°C (41°F to 131°F)
Nonoperating
–40°C to 70°C (–40°F to 158°F)
1.8.2
Temperature gradient
Operating
20°C per hour (36°F per hour)
Nonoperating
30°C per hour (54°F per hour)
1.8.3
Relative humidity
Operating
8% to 80% noncondensing
Maximum wet bulb 26°C (79°F)
Operating gradient, max
10% per hour
Nonoperating
5% to 95% noncondensing
Maximum wet bulb 26°C (79°F)
1.8.4
Altitude
Operating
–1,000 ft to 10,000 ft (–305 m to 3,048 m)
Nonoperating
–1,000 ft to 40,000 ft (–305 m to 12,192 m)
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
0.020-inch
displacement
22–500 Hz vibration
0.50 Gs
4.00 Gs
During operating shock and vibration, there is no physical damage to the
drive or performance degradation. During nonoperating shock and vibration, the read/write heads are positioned in the shipping zone.
1.10 Start and stop time
If the motor start option is disabled, the drive becomes ready within
20 seconds after power is applied. If the motor start option is enabled,
the drive becomes ready within 20 seconds after it receives the Motor
Start command. The drive stops within 15 seconds, whether the drive is
commanded to spin down or power is removed.
1.10.1 Power-up sequence
The following typical power-up sequence is provided to assist in evaluating drive performance. This information does not constitute a specification or a performance guarantee.
1. Power is applied to the disc drive.
2. When power is applied, the LED is on for about 5 seconds. Either of
following two sequences can occur, depending on whether a jumper
is installed on pins 3 and 4 of the options jumper block shown in
Figure 7 on page 25.
a. If a jumper is not installed on pins 3 and 4 of the options jumper
block, the remote start option is not enabled. The drive begins to
spin up as soon as power is applied.
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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. The spindle motor reaches operating speed in about 5 seconds. After
5 seconds, there are no speed variations.
7. The drive performs velocity adjustment seeks.
8. The drive loads RAM code from the disc. During RAM code loading,
the LED flashes for approximately 1 second.
9. The drive seeks track 0 and becomes ready.
1.10.2 Power-down sequence
The following typical power-down sequence is provided to assist in
evaluating drive performance. This information does not constitute a
specification or a performance guarantee.
1. The power cable is unplugged from the drive, or the drive is commanded to spin down.
2. Within 3 seconds after the motor begins to spin down, the actuator
lock engages, producing an audible sound.
3. The spindle stops within 15 seconds, whether the power cable is
unplugged from the drive or the drive receives the power-down
command.
1.10.3 Auto-park
Upon power-down, the read/write heads automatically move to the
shipping zone. The heads park inside the maximum data cylinder. When
power is applied, the heads recalibrate to track 0.
Caution. Do not move the drive until the spindle motor has come to a
complete stop, otherwise you may damage the drive.
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.
1.11.1 Input noise
+5V
+12V
Voltage tolerance
(including noise)
± 5%
± 5%
Input noise frequency
(max)
25 MHz
25 MHz
Input noise
(max, peak-to-peak)
100 mV
240 mV
1.11.2 Power management
The drive supports power-management modes that reduce its overall
power consumption. The drive automatically changes from one mode to
another based in response to interface activity. You do not need to
change any parameters or send any special commands to make the drive
change modes. The power-management modes are described below.
• Spinup. The spindle is coming up to operating speed. The power
consumed in this mode is equivalent to the average power during the
first 10 seconds after the drive begins to spin up. Refer to the startup
current chart in Figure 1 on page 9 for a typical representation of power
consumption during spinup.
• Seeking. The servo electronics are active and the read/write heads
are moving to a specific location on the disc. The read/write electronics
are powered-down. The power consumed in this mode is equivalent
to the average power measured while executing random seeks with
a 2-revolution (26.6 msec) dwell between seeks. The drive enters this
mode from the Idle mode.
• Read/write. The drive is reading or writing. All electronics are active
and the read/write heads are on track. The drive enters this mode from
the Idle mode.
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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. The terminating resistor packs are
removed and terminator power is supplied through the SCSI connector.
All values are measured 10 minutes after the drive spins up.
Spinup
Seeking
Read/
Write
Idle
Amps peak
1.90
—
—
—
RMS amps typ
—
0.408
0.241
0.208
Watts typ
—
4.90
2.9
2.5
RMS amps typ
—
0.16
0.470
0.1
Watts typ
—
0.8
2.35
0.5
7.00
5.70
5.25
3.0
Current at +12V
Current at +5V
Power
Total watts typ
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.
T5
The actuator-lock solenoid releases the arm.
T6
The final speed-control lock is achieved.
T7
The servo is calibrated.
T8
The servo locks in on track 0 and the drive is ready.
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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). As such, a drive is considered to be a subassembly even when
individually marketed to the customer. As a subassembly, no Federal
Communications Commission authorization, verification or certification
of the device is required.
Seagate Technology, Inc. has tested these drives in an enclosure as
described above to ensure that the total assembly (enclosure, disc drive,
motherboard, power supply, etc.) does comply with the limits for a
Class B computing device, pursuant to Subpart J of Part 15 of the FCC
rules. Operation with noncertified assemblies is likely to result in interference to radio and television reception.
Radio and television interference. This equipment generates and uses
radio frequency energy and, if not installed and used in strict accordance
with the manufacturer’s instructions, may cause interference to radio and
television reception.
This equipment is designed to provide reasonable protection against
such interference in a residential installation. However, there is no
guarantee that interference will not occur in a particular installation. If this
equipment does cause interference to radio or television, which can be
determined by turning the equipment on and off, you are encouraged to
try one or more of the following corrective measures:
• Reorient the receiving antenna.
• Move the device to one side or the other of the radio or TV.
• Move the device farther away from the radio or TV.
• Plug the equipment into a different outlet so that the receiver and
computer are on different branch outlets.
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. This digital apparatus does not exceed the Class B limits for radio
noise emissions from computer equipment as set out in the radio
interference regulations of the Canadian Department of communications.
Le présent appareil numérique n′émet pas de bruits radioélectriques
dépassant les limites applicables aux appareils numériques de Classe B
prescrites dans le règlement sur le brouillage radioélectrique édicté par
le Ministère des Communications du Canada.
Sicherheitsanleitung
1. Das Gerrät ist ein Einbaugerät, das für eine maximale Umegebungstemperatur von 55°C vorgesehen ist.
2. Zur Befestigung des Laufwerks werden 3 Schrauben 6-32 UNC-2A
benötigt. Bei seitlicher Befestigung darf die maximale Länge der
Schrauben im Chassis nicht mehr als 3,3 mm und bei Befestigung an
der Unterseite nicht mehr als 5,08 mm betragen.
3. Als Versorgungsspannugen werden benötigt:
+5V ± 5% 0,5A
+12V ± 5% 0,5A (1,9A fur ca. 30 Sek. fur ± 10%)
4. Die Versorgungsspannung muβ SELV entsprechen.
5. Alle Arbeiten dürfen nur von ausgebildetem Servicepersonal durchgeführt werden.
6. Der Einbaudes Drives muβ den Anforderungen gemäβ DIN IEC 950V
DC 0805/05.90 entsprechen.
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.
The physical interface consists of single-ended drivers and receivers
using asynchronous or synchronous communication protocols that support cable lengths of up to 6 meters (3 meters for Fast SCSI) and a bus
interface transfer rate up to 5 Mbytes per second asynchronous and
10.0 Mbytes per second synchronous. The bus protocol supports multiple initiators, disconnect and reconnect, additional messages, and 6-byte
and 10-byte command descriptor blocks.
2.1
SCSI-2 compatibility
The drive interface is described in the Seagate Wren SCSI-2 Interface
Product Manual, publication number 77765466. The drive complies with
the mandatory subset of the ANSI SCSI-2 interface. The Fast SCSI-2
interface is based on the ANSI Small Computer System Interface-2
(SCSI-2): document number ANSI X3.131-199x (X3T9.2/86-109
Rev. 10h).
2.2
Handling and static-discharge precautions
After you unpack the drive, and before you install it in a system, be careful
not to damage it through mishandling. Observe the following standard
handling and static-discharge precautions:
Caution:
• Keep the drive in its static-shielded bag until you are ready to complete
the installation. Do not attach any cables to the drive while it is in its
static-shielded bag.
• Before handling the drive, put on a grounded wrist strap, or ground
yourself frequently by touching the metal chassis of a computer that
is plugged into a grounded outlet. Wear a grounded wrist strap
throughout the entire installation procedure.
• Handle the drive by its edges or frame only.
• The drive is extremely fragile—handle it with care. Do not press down
on the drive top cover.
• Always rest the drive on a padded, antistatic surface until you mount
it in the host system.
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. Some
factory-installed labels contain information needed to service the
drive. Others are used to seal out dirt and contamination.
2.3
Hot-plugging
If there is more than one SCSI device daisy-chained on the bus, you can
connect and disconnect the drive I/O and power connector if the following
conditions are met:
• The drive you are disconnecting (or connecting) is not the device
supplying terminator power or terminating resistance to the bus.
• During hot-plugging, do not add or remove terminator power or
resistors from the bus.
• During hot-plugging, do not use the bus for I/O transactions. If you are
installing a drive on the bus, there must be no I/O transactions until
the drive is connected and ready. If you are removing a drive from the
bus, there must be no I/O transactions until the drive is completely
disconnected.
To avoid damage to the disc and head, the spindle must be completely
stopped and the heads must be parked before you remove the drive from
the system. There are two ways to stop the spindle and park the heads:
• If the drive is not configured to use the remote start/stop feature,
disconnect the DC power cable from the drive DC power connector
and wait 30 seconds.
• If the drive is configured to use the remote start/stop feature, issue the
SCSI stop command and wait 30 seconds.
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. The SCSI devices at
both ends of the daisy-chain must be terminated; the intermediate SCSI
devices should not be terminated.
The 50-conductor, nonshielded mating cable connector consists of two
rows of 25 female contacts with adjacent contacts 0.100 inches apart.
The recommended mating cable connector part numbers are shown in
the table below. The mating cable is shown in Figure 2 on page 16.
The following table shows 3M connector part numbers for interface
cable connectors compatible with the drive. These connectors do not
have a center key; they are available with or without a strain relief.
No strain relief
No center key
With strain relief
No center key
Closed end
(for cable ends)
3M
3425-7000
3M
3425-7050
Open end
(for daisy-chain)
3M
3425-6000
3M
3425-6050
The following table shows Molex connector part numbers for connectors that have a center key.
Closed end
(for cable ends)
Molex
39-51-2504
Open end
(for daisy-chain)
Molex
39-51-2501
Two strain reliefs, shown in the following table, are available for the
connectors referred to in the previous table.
Molex strain relief,
preferred version
in Europe
Molex 90170-0050
Molex strain relief,
preferred version
in Japan
Molex 15-25-1503
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 (0.97)
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
0.120
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.
Signal name
Signal
pin number
Ground
pin number
DB(0)–
2
1
DB(1)–
4
3
DB(2)–
6
5
DB(3)–
8
7
DB(4)–
10
9
DB(5)–
12
11
DB(6)–
14
13
DB(7)–
16
15
DB(P)–
18
17
Ground
19–22
—
Reserved
23–25
—
Terminator power
26
—
Reserved
27–28
—
Ground
29–30
—
ATN–
32
31
Ground
33–34
—
BSY–
36
35
ACK–
38
37
RST–
40
39
MSG–
42
41
SEL–
44
43
C/D–
46
45
REQ–
48
47
I/O–
50
49
Caution. Do not connect pin 25 to ground. If you plug in the connector
upside down, the terminator power on pin 26 is shorted to
ground. This can damage the drive.
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. If your
design uses both shielded and nonshielded cables within the same SCSI
bus, you must allow for the effects of impedance mismatch.
To minimize noise effects, use a minimum conductor size of 28 AWG.
Use only nonshielded cable connectors. Use a 50-conductor flat cable
or 25-conductor twisted-pair cable. The recommended nonshielded flat
cable part numbers are shown in the following table:
Part
Manufacturer
Flat Cable
3M-3365-50
Twisted Pair
Spectra Twist-N-Flat 455-248-50
2.6
Single-ended cable
The single-ended SCSI cable must meet the following requirements:
• The cable cannot be longer than 6.0 meters.
• A cable stub cannot be longer than 0.1 meter, from the mainline
interconnection to any device. Stubs must be separated by at least
0.3 meter.
2.6.1
Fast synchronous data transfer
When using fast synchronous data transfer rates, the SCSI interface
cable must meet the following additional requirements:
• The cable cannot be longer than 3.0 meters.
• A characteristic impedance of 90 ohms to 132 ohms is recommended
for nonshielded flat cable or twisted-pair ribbon cable.
• The signal attenuation at 5 MHz must not be greater than 0.095 dB
per meter.
• The DC resistance at 20°C must not exceed 0.230 ohms per meter.
• The propagation delay delta of a shielded, twisted-pair cable must not
exceed 20 nsec per meter.
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.
When installing or removing terminators, follow these guidelines:
• If you are installing only one drive, and your system contains only one
initiator (for example, a stand-alone host computer) leave the terminators installed on the drive.
• If you are installing multiple drives in a daisy-chain configuration,
remove the terminators from all drives except the drives (or initiators)
connected to the ends of the cable.
• If your application requires no terminators, remove the terminators
from the drive circuit board. Removing the terminator power source
selection jumper does not disconnect the terminator resistors from the
circuit.
• If you use Fast SCSI transfer rates, you must use the active termination options. See Sections 2.8.1 and 2.9.5. If the transfer rate is
5.0 Mbytes per second or less, you can use either method of termination.
2.8.1
Active termination
All interface signals are single-ended and must be terminated at the drive
with a 110-ohm resistor to +2.85V. This is the default. The Seagate® part
number for the 110-ohm terminator is 502155-001.
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. The
Seagate part number for the 220/330-ohm terminator is 75916526-9.
Single-ended SCSI devices providing termination power have the following characteristics:
Terminator voltage (V)
4.0 to 5.25
Source drive capability (mA, min)
800
Line driver
(transmitter or transceiver)
+5V
+5V
220
ohms
220
ohms
330
ohms
ANSI SCSI
compatible circuit
Figure 5. Passive termination
Flat cable pair
Line receiver
330
ohms
ANSI SCSI
compatible
circuit
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. The drive uses an ANSI SCSI singleended receiver with hysteresis gate or equivalent as a line receiver.
The loss in the cable is defined as the difference between the voltages
of the input and output signals, as shown below:
Logic level
Driver output (x)
Receiver input (x)
Asserted (1)
0.0V ≤ x ≤ 0.4V
0.0V ≤ x ≤ 0.8V
Negated (0)
2.5V ≤ x ≤ 5.25V
2.0V ≤ x ≤ 5.25V
2.9
Jumper configurations
The jumper blocks are shown in Figure 6 on page 24 and Figure 7 on
page 25. The jumper applications and part numbers are listed below:
Jumper size
Part number
Application
2-mm
Seagate PN 13211-001
Du Pont PN 89133-001,
Methode PN 8618-202-70,
or equivalent
J5 and J8 only
0.1-inch
Seagate PN 10562-001
Du Pont PN 86214,
Molex PN 87092-3013,
or equivalent
All jumper blocks
except J5 and J8
2.9.1
Parity enable option
When a jumper is installed on pins 1 and 2 of the options jumper block,
the parity bit is used. This is the default. When a jumper is not installed
on pins 1 and 2 of the options jumper block, the parity bit is not used.
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). If you install a second drive, you can use
any available ID. SCSI ID 2 is recommended.
When selecting the SCSI ID, you can install jumpers on either (not both)
of the following jumper blocks:
• The SCSI ID jumper block
• The user-configuration jumper block (pins 1–6 only)
Note. If you install SCSI ID jumpers on both the SCSI ID jumper block
and the user-configuration jumper block (pins 1–6), the drive may
not function properly.
2.9.4
Terminator power source jumper block
To select the termination power source, install jumpers as follows:
• To provide terminator power to the SCSI connector and the drive
terminator packs, install jumpers on pins 1 and 2 and pins 3 and 4 of
the terminator power source jumper block. This is the default.
• To select the drive power connector as the termination power source
for the resistor packs, install a jumper on pins 1 and 3 of the terminator
power source jumper block.
• To select the SCSI connector as the termination power source for the
resistor packs, install a jumper on pins 1 and 2 of the terminator power
source jumper block.
• To provide terminator power to the SCSI connector from the drive
power connector only, install a jumper on pins 3 and 4 of the terminator
power source jumper block.
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. Terminator power
source jumper block
3 1
4 2
SCSI ID = 5
Circuit
board
SCSI ID = 6
SCSI ID = 7
From SCSI connector
From power connector
To SCSI connector only
J3. DC power connector
1
2
3
4
From power connector
and to SCSI bus
Terminating resistors
not installed
Figure 6. Configuration jumpers, back view
Circuit board
+5V
+5V return
+12V return
+12V
Circuit
board
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.
Clock ground
Remote LED −
Remote LED +
Reserved. Do not
use.
SCSI ID = 0
SCSI ID = 1
SCSI ID = 2
SCSI ID = 3
SCSI ID = 4
SCSI ID = 5
SCSI ID = 6
SCSI ID = 7
LSB
Figure 7. Configuration jumpers, front view
MSB
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. When installing jumpers on the options jumper block and the
user-configuration jumper block, be careful to install jumpers
on the correct pins. Install jumpers only on pins 1 through 4 of
the options jumper block and pins 1 through 6 of the user-configuration jumper block. If you install jumpers on pin pairs that
are meant to accept only twisted pair connectors, the drive
may not function properly.
2.10 Remote LED connection
Remote LED pins are located on two separate jumper blocks: the options
jumper block and the user-configuration jumper block. Attach a two-pin
remote LED connector to either jumper block, as follows:
• User-configuration jumper block, pins 9 and 10. Use any 2-pin, 2-mm
connector and an LED from LiteOn, part number LTL-3231A.
• Options jumper block, pins 7 and 8. Use any 2-pin, 0.1-inch connector
and an LED from LiteOn, part number LTL-3231A.
2.11 External spindle synchronization option
You can synchronize the spindle motors of an array of drives by connecting a twisted pair to each drive. The maximum cable length is 6 feet
(1.8 meters).
Spindle synchronization pins are located on two separate jumper blocks:
the options jumper block and the user-configuration jumper block. Use
either jumper block to synchronize an array of drives, as follows:
• User-configuration jumper block. Use one strand of the twisted pair
to connect together pin 7 of the user-configuration jumper block of
each drive. Use the other strand to connect together pin 8 of the
user-configuration jumper block of each drive.
• Options jumper block. Use one strand of the twisted pair to connect
together pin 5 of the options jumper block of each drive. Use the other
strand to connect together pin 6 of the options jumper block of each
drive.
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. The drive that
becomes ready first checks for the reference signal, and when it does
not detect a pulse, it takes over as the master and begins sending
reference pulses. All other drives synchronize their spindles to the
reference signal as they in turn become ready.
T1
T2
Spindle clock
Internal index
T3
Figure 8. External spindle clock timing diagram
T1
Spindle clock period
13.34 msec ± 0.5%
T2
Duty cycle
0.5 µsec min
500 µsec max
T3
Spindle clock leading edge to
index leading edge
0 µsec ± 250 µsec
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. Do not remove factory-installed labels from the drive or cover
them with additional labels. If you do, you may void your
warranty. Factory-installed labels contain information required
when servicing the product.
2.12.1 Bottom mounting holes
Use 6-32 UNC screws in three of the four available bottom mounting
holes as shown in Figure 9.
Caution. Do not insert the bottom mounting screws more than
0.20 inches (6 turns) into the drive frame. If you use a screw
that is too long, you could damage the drive.
2.12.2 Side mounting holes
Use 6-32 UNC screws in three of the six available side mounting holes
as shown in Figure 2 on page 12. Do not use all three mounting holes
on the same side of the drive.
Caution. Do not insert side mounting screws more than 0.13 inches
(4 turns) into the drive frame. If you use a screw that is too
long, you could damage the drive.
ST3655 Family SCSI Drives Product Manual, Rev. A
Interface
connector
Power
connector
Figure 9. Drive mounting orientations
29
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. Drive mounting dimensions
4.02 (102.11) max
1.750 ± 0.010
(44.450 ± 0.254)
3.750 ± 0.010 (95.250 ± 0.254)
2.375 ± 0.020
(60.325 ± 0.508)
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.
• The three most significant bits (bits 7–5) of byte 1 contain the logical
unit number (LUN), which is always zero.
• If the link bit is zero, the flag bit must be zero; otherwise, the drive
returns a check condition status. If the link bit is one and the drive
completes the command without error, the flag bit specifies which
message the drive returns to the initiator. If the flag bit is zero, the
drive sends the linked command complete message. If the flag bit is
one, the drive sends the linked command complete with flag message.
32
ST3655 Family SCSI Drives Product Manual, Rev. A
3.2
Status byte codes
After the drive terminates each command, the drive sends the status byte
(shown below) to the initiator during the status phase, unless the command is terminated by one of the following methods:
• An abort message
• A bus device reset message
• A hard reset
• A catastrophic reset condition
Bytes
0
Bits
7
6
Reserved
0
0
5
4
3
2
Status byte code
1
0
RSVD
0
The status byte code can be any of the following:
00H
Good status. The drive has successfully completed execution of
a command.
02H
Check condition status. The drive detected an error, an exception, or an abnormal condition. In response, the initiator may issue
a Request Sense command to determine the nature of the condition.
08H
Busy status. The drive is busy, and is, therefore, unable to accept
a command from an initiator. The initiator retries the command
later. The drive returns a busy status if the initiator has not sent
the disconnect message and tries to queue a command or if the
initiator rejects the disconnect message and the queue is not
empty.
10H
Intermediate status. The drive successfully completed a command that was one of a series of linked commands without issuing
a check condition status or reservation conflict status. (Had the
drive not returned an intermediate status, the series of linked
commands would have been terminated.)
18H
Reservation conflict status. A SCSI device tried to access the
drive, but was unable to because the drive was already reserved
by another SCSI device.
28H
Queue full status. The drive received a command, but rejected
it because the queue was full. The drive only uses this status if
tagged command queuing is implemented.
ST3655 Family SCSI Drives Product Manual, Rev. A
3.3
Supported commands
The drive supports the commands listed below.
Group 0 commands
Operation code
Test Unit Ready
00H
Rezero Unit
01H
Request Sense
03H
Format Unit
04H
Reassign Blocks
07H
Read
08H
Write
0AH
Seek
0BH
Inquiry
12H
Mode Select
15H
Reserve
16H
Release
17H
Mode Sense
1AH
Start/Stop Unit
1BH
Receive Diagnostic Results
1CH
Send Diagnostic
1DH
Group 1 commands
Operation code
Read Capacity
25H
Read Extended
28H
Write Extended
2AH
Seek Extended
2BH
Write and Verify
2EH
Verify
2FH
Read Defect Data
37H
Write Data Buffer
3BH
Read Data Buffer
3CH
Read Long
3EH
Write Long
3FH
33
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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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
LUN
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
3.4.2
Rezero Unit command (01H)
The Rezero Unit command requests that the drive set its logical block
address to zero and return the read/write heads to the track (or cylinder)
containing logical block 0.
This command is intended for systems that disable retries and the initiator
performs error recovery. It is longer than a seek to logical block address 0
and should be used if seek errors are encountered.
When used with a host adapter that supports disconnection, the drive
disconnects when this command is received.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
2
0
LUN
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
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. This sense data is saved for the initiator
until:
• The initiator requests the sense data using the Request Sense command, or
• Another command is received from the initiator that issued the command, resulting in the check condition status.
If any of the following fatal errors occur during a Request Sense command, the drive sends a check condition status and the sense data may
be invalid.
• The drive receives a nonzero reserved bit in the CDB.
• An unrecovered parity error occurs on the data bus.
• A malfunction prevents return of sense data.
If any other error occurs during the Request Sense command, the drive
returns sense data with good status.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
1
LUN
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
Flag
Link
4
5
Allocation length
0
0
0
0
0
Byte 4 The allocation length specifies the maximum number of bytes
the initiator has allocated for returned sense data. The drive
returns up to, but no more than, 22 bytes of sense data. Therefore, if you want the initiator to receive all of the sense data, set
the allocation length to 22 bytes or more. If you set the allocation
length to zero, no sense data is 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 3.4.11 for more information about reservations.
The initiator can specify (or not specify) sectors to be reallocated during
the formatting process.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
1
0
0
1
2
Fmt Cmp
Data
lst
LUN
0
0
0
3–4
5
0
0
Defect list format
0
0
0
0
Flag
Link
Interleave
0
0
0
0
0
Byte 1
The Fmt Data (format data) bit, the Cmp lst (complete list)
bit, and the defect list format field are described in Section 3.4.4.2.
Bytes 3–4
If the interleave field is not supported, it can contain any
value. However, the drive always formats the disc with an
interleave of 1:1.
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.
• The data defect list (D-list) is a list of sectors supplied to the drive by
the initiator during a data-out phase of the current Format Unit
command. The drive sends the D-list in the last bytes of the defect list
described in Section 3.4.4.3.
• The grown defect list (G-list) is a list of sectors that contain media
flaws. The drive reallocated these sectors during the last Reassign
Blocks command, or they are data defects (D-list) reallocated during
a previous Format Unit command, or they are defects that have been
automatically reallocated by the drive. This G-list is recorded on the
disc and can be referenced by current and subsequent Format Unit
commands. The G-list does not include P-list defects.
• The certification defect (C-list) is a list of sectors that were incorrectly
formatted by the drive during the Format Unit command. This list is
created when the DCRT bit of the defect list header is set to zero.
3.4.4.2
Format Unit parameters
For each format listed below, except the default format, the initiator sends
a defect list header. This header is described in Section 3.4.4.3. The
bytes-from-index format is described in Section 3.4.4.4 and the physical
sector format is described in Section 3.4.4.5. The block format is not
discussed.
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). All sectors are then reallocated
using the P-list and the current G-list. At
the end of the format, the new G-list and
defect tables are stored on a reserved
area of the disc.
1
1
0
0
1
1
0
Format option with the G-list and D-list.
The initiator does not send a D-list to
the drive. The drive uses the existing Glist to find defects and adds new defects
to the existing G-list in the bytes-fromindex format.
0
1
Format option with the G-list and D-list.
The initiator does not send a D-list to
the drive. The drive uses the existing Glist to find defects and adds new defects
to the existing G-list in the physical
sector format.
0
1
1
0
X
Format option without G-list or D-list is
selected, the initiator sends a defect list
X
header, but no D-list. The drive erases
any previous G-list.
1
1
1
0
0
1
1
1
0
1
Format option with D-list. The initiator
sends the defect list header followed by
a D-list in the bytes-from-index format.
The drive erases any previous G-list.
Format option with D-list and without Glist. The initiator sends a defect list
header followed by a D List of defects to
be reallocated. The D list is in the
physical sector format. Any previous Glist is erased.
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. If the FOV bit is 0, the DPRY, DCRT and STPF
bits are checked for zeros.
If the DPRY bit is 1, the defects described in the P-list are
not reallocated during formatting. This means existing reallocations of the P-list are canceled and no new reallocations
are made during formatting. The P-list is retained. If the
DPRY bit is 0, the defects described in the P-list are
reallocated during formatting. A check condition status is
sent if the P-list cannot be found.
If the DCRT bit is 1, the drive does not verify the data written
during the format. Therefore, no C-list for this format is
created or reallocated. If the DCRT is 0, the drive verifies
the data written during the format, creates a C-list and
reallocates sectors that were incorrectly formatted.
If the STPF bit is 1, the drive stops formatting if it encounters
an error while accessing either the P or G defect list. If the
STPF bit is 0, the drive continues formatting even though it
has encountered an error while accessing either the P or G
defect list.
Bytes 2–3
The defect list length is the length, in bytes, of the defect list
that follows the header. For each sector to be reallocated,
the defect list contains 1 defect descriptor containing
8 bytes in either the bytes-from-index format or the physical
sector format. These formats are explained in Sections 3.4.4.4 and 3.4.4.5, respectively.
Bytes 4–n The two types of defect descriptors are described in Sections 3.4.4.4 and 3.4.4.5.
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. Each defect
descriptor is comprised of the cylinder number of the defect, the head
number of the defect, and the number of bytes-from-index to the defect
location. The defect descriptors are always listed in ascending order.
A value for defect bytes-from-index of FFFFFFFFH (which means reassign the entire track) is illegal.
The information in the following table is repeated for each defect.
Bit
Byte
7
6
5
4
3
2
0–2
Cylinder number of defect
3
Head number of defect
4–7
Defect bytes-from-index
1
0
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. The defect
descriptors must be in ascending order.
A defect sector number of FFFFFFFFH (which means reassign the entire
track) is illegal.
Note. The initiator cannot use any previously defined C, G or D lists if
the sector size (block length) has been changed by the Mode
Select command. For more information on the Mode Select command, see Section 3.4.10.
The information in the following table is repeated for each defect.
Bit
Byte
7
6
5
4
3
2
0–2
Cylinder number of defect
3
Head number of defect
4–7
Defect sector number
1
0
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. The initiator uses this command to immediately
reallocate any block (sector) that requires the drive to recover data using
ECC if the automatic reallocation feature is not enabled.
Note. Before sending this command, the initiator should recover the data
from the logical blocks to be reassigned. After completing this
command, the initiator can write the recovered data to the same
logical block addresses.
After sending the Reassign Blocks command, the initiator transfers a
defect list containing the logical block addresses to be reassigned. The
drive reassigns the logical blocks. The data contained in the logical
blocks is not preserved.
The drive can repeatedly assign a logical block to multiple physical
addresses until there are no more spare locations available on the disc.
If the drive does not have enough spare sectors to reassign all of the
defective logical blocks, the command terminates with a check condition
status and the sense key is set to media error. The logical block address
of the first logical block not reassigned is returned in the information bytes
of the sense data.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
1
1
1
0
0
0
0
0
1
LUN
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
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. The defect list length is
equal to four times the number of defect descriptors.
Bytes 4–n The defect descriptor contains the 4-byte logical block
address of the defect. The defect descriptors are always in
ascending order.
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.
In systems that support disconnection, the drive disconnects when a valid
Read command is received, unless the data is available in the cache
buffer and the drive does not need to access the disc. The buffer full ratio
byte of the Disconnect/Reconnect page determines when the drive
reconnects. (The Disconnect/Reconnect page is discussed in Section C.2.) After the drive starts transferring data to the initiator, the drive
does not disconnect unless an internal error recovery procedure is
required or the data transfer to an initiator is interrupted for more than
1 millisecond.
Because the drive uses read look-ahead and caching functions, it may
read more data into the buffer than specified by the transfer length in the
CDB.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
1
0
0
0
1
LUN
Logical block address (MSB)
2
Logical block address
3
Logical block address (LSB)
4
Transfer length
5
Control byte (00H)
Bytes 1–3
The logical block address specifies the logical block where
the read begins.
Byte 4
The transfer length specifies the number of contiguous
logical blocks of data to be transferred. A transfer length
of 0 indicates that 256 logical blocks are to be transferred.
Any other value indicates the number of logical blocks to be
transferred.
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.
If the system supports disconnection, the drive can disconnect and
reconnect while executing this command. The drive disconnects when
any of the following conditions arise:
• An internal error recovery procedure is required.
• The data transfer with the initiator is interrupted for more than 1 msec.
• The drive’s internal data buffer is full.
The buffer empty ratio in the Disconnect/Reconnect page determines
when the drive reconnects. Section C.2 documents the Disconnect/Reconnect page.
The initiator must continue sending write data to the drive until the drive
sends a command complete status or until the initiator resets or aborts
the command.
If there is a reservation access conflict, this command terminates with a
reservation conflict status and no data is written. For more information
about the reservation conflict status, see Section 3.2.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
1
0
1
0
1
LUN
Logical block address (MSB)
2
Logical block address
3
Logical block address (LSB)
4
Transfer Length
5
Bytes 1–3
0
0
0
0
0
0
Flag
Link
The logical block address specifies the logical block where
the write operation begins.
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. This command is seldom used because all commands
that access the disc contain implied seeks. In systems that support
disconnection, the drive disconnects when it receives a valid Seek
command.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
1
0
1
1
1
LUN
Logical block address (MSB)
2
Logical block address
3
Logical block address (LSB)
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
Bytes 1–3
The logical block address specifies the logical block the
head seeks. For the maximum logical block address that
may be specified for a Seek command, see Section 3.5.1.
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.
If an Inquiry command is received from an initiator with a pending
unit-attention condition (before the drive reports a check condition
status), the drive performs the Inquiry command and the Unit Attention
condition is not cleared.
The initiator should allocate 36H bytes for inquiry data. The inquiry data
returned to the initiator is summarized in Appendix D.
Bit
Byte
7
0
0
1
2
3
6
5
4
3
2
1
0
0
1
0
0
1
LUN
0
0
0
Page code
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Flag
Link
4
5
0
EVPD
Reserved
0
0
Allocation length, in bytes
0
0
0
0
0
0
Byte 1 If the EVDP (Enable Vital Product Data) bit is zero, the drive
returns the standard inquiry data. If the EVDP bit is one, the drive
returns the optional vital product data specified in byte 2.
Byte 2 The page code field specifies which page of the vital product
information the drive returns.
Byte 4 The allocation length specifies the number of bytes the initiator
has allocated for returned inquiry data. An allocation length of 0
indicates that no inquiry data is transferred. This condition is not
considered an error. Any other value indicates the maximum
number of bytes to be transferred. The allocation length should
be at least 36H to allow the initiator to receive all of the inquiry
data.
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. After a power-on reset, hard reset
or bus device reset, the current values are equal to the saved values
if the saved values can be retrieved, or the default values if the saved
values cannot be retrieved.
• Changeable values copy. This copy does not actually contain any
parameters. Instead, it contains a map of each mode page indicating
which parameter values are changeable by the initiator. If a bit
contains a 1, the corresponding value in the mode page is changeable. If a bit contains a 0, the corresponding value in the mode page
is not changeable. The changeability values for each bit of each mode
page are listed in Appendix C with the default values.
• Default values copy. This copy contains the parameter values the
drive used as its current values when it was manufactured. The drive
defaults to these values after a reset condition, unless valid saved
values are available. The default values are listed in Appendix C.
• Saved values copy. The saved values are the values the drive stores
on the disc. If the parameter is changeable, these values can be set
using a Mode Select command. If the parameter is not changeable,
the default values are always used.
The drive has one set of mode parameters for each initiator on the SCSI
bus. If the initiator that issued the Mode Select command changes a
parameter that applies to another initiator, the drive generates a sense
key of unit attention with an additional sense of mode parameters
changed (26H) for all the other initiators. The sense keys and additional
sense codes are discussed in Appendix B.
Before sending any Mode Select commands, the initiator should send a
Mode Sense command requesting that the drive return all pages with
changeable values. The initiator uses this information to determine which
pages are supported, the proper length for those pages, and which
parameters in those pages can be changed for that logical unit.
When the drive receives the Mode Select command, it updates the
savable parameters with the current values included in the Mode Select
command. After the drive saves the parameters, the drive reports a good
status. The drive verifies only mode select data that is defined as
changeable.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
0
1
0
1
PF = 1
0
0
0
SP
1
LUN
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
Flag
Link
4
5
Parameter list length
0
0
0
0
0
Byte 1 The page format (PF) bit is always one. This means that the data
sent by the initiator after the mode select header and block
descriptors complies with the page format.
When the SP (save mode parameters) bit is 1, the drive saves
the savable pages in RAM and on the disc. When the SP (save
mode parameters) bit is 0, the drive saves the savable pages in
RAM only, which means that the parameters are lost when the
drive is powered down. When the drive executes the Mode
Select command, it does not save the Format Device page (03H)
and the Rigid Disc Geometry page (04H); it saves these pages
during the Format Unit command.
Byte 4 The parameter list length specifies the length, in bytes, of the
header and mode page transferred to the drive. A parameter list
length of 0 means that no data is transferred. To calculate the
parameter list length for any given mode page, add the parameter list header (4 bytes), the block descriptor (if any, 8 bytes), the
2-byte mode page header and the length of the mode page. For
the lengths of the mode pages, refer to Appendix C.
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.
Bit
Byte
7
6
5
4
3
2
1
0
Parameter list header
0 (default)
Reserved (00H)
1 (default)
Medium type (00H)
2 (default)
Reserved (00H)
3 (default)
Block descriptor length (00H or 08H)
Block descriptor data
4 (default)
Density code (00H)
5–7
Number of blocks
8 (default)
Reserved (00H)
9–11
Block length
Parameter information
12–n
Mode pages
Byte 1
The medium type field is always 00H, which means that the
drive is a direct access device.
Byte 3
If the block descriptor length is 8 bytes, a block descriptor
is sent to the drive. If the block descriptor length is 0 bytes,
no block descriptor is sent to the drive.
Byte 4
The density code is always 00H and cannot be changed.
Bytes 5–7
The number of blocks is equal to the guaranteed sectors,
which is listed in the formatted capacity section of the
appropriate product manual.
Bytes 9–11 The block length is always 512 and cannot be changed.
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.
When the drive receives the superseding Reserve command, the
previous reservation is canceled.
• Released by a Release command from the same initiator. See the
Release command in Section 3.4.12.
• Released by a bus device reset message from any initiator
• Released by a hard reset
After the drive honors the reservation from one initiator, it accepts only
Request Sense and Inquiry commands from other initiators; the drive
rejects all other commands with a reservation conflict status.
Bit
Byte
7
0
0
1
6
5
0
0
LUN
4
1
3rd pty
3
2
1
0
1
1
3rd party device ID
0
0
Extent
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
Byte 1 If the 3rd pty bit is 0, the initiator reserves the drive for itself. If
the 3rd pty bit is 1, the initiator reserves the drive for another
initiator. The SCSI ID of the third-party initiator is specified in the
3rd party device ID field.
The extent bit must always be 0. The drive does not support
extent reservations. If the Extent bit is 1, the drive generates a
check condition status.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
0
1
1
1
1
LUN
3rd pty
3rd party device ID
Extent
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag
Link
Byte 1 If the 3rd pty bit is 0, the initiator releases its own reservation. If
the 3rd pty bit is 1, the initiator releases the drive for another
initiator. An initiator can only release a third party reservation that
it made. The SCSI ID of the third-party initiator is specified in the
3rd party device ID field.
The extent bit must always be 0. The drive does not support
extent reservations. If the extent bit is 1, the drive generates a
check condition 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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
1
0
1
0
0
0
0
0
0
0
0
0
0
Flag
Link
1
LUN
2
3
PCF
0
Page code
0
0
4
5
0
0
Allocation length
0
0
0
0
0
Byte 2 The PCF (page control field) determines the content of Mode
Parameter bytes. Regardless of the value of the PCF, the block
descriptor always contains the current values.
PCF bit 7 PCF bit 6
Effect
0
0
Return current values.
0
1
Return changeable values.
1
0
Return default values.
1
1
Return saved values.
The page code is the designator that is unique to each page.
The page codes are listed in Section 3.4.13.1.
Byte 4 The allocation length specifies the number of bytes that the
initiator has allocated for returned Mode Sense data. An allocation length of 0 means that no Mode Sense data is to be
transferred. This condition is not considered an error. Any other
value represents the number of bytes to be transferred. For a
description of the allocation length, see Section 3.4.13.1.
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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. You can transfer mode pages to the
initiator either of two ways:
• Transfer all mode pages at once by using page code 3FH, as described in the last row of this table, or
• Transfer one mode page at a time by using the page code and
allocation length of the mode page.
Page
code
01H
02H
03H
04H
08H
0CH
0DH
Allocation
length
Mode Sense data returned
18H
4 bytes of Mode Sense header
8 bytes of block descriptor
2 bytes of mode page header
10 bytes of Error Recovery parameters
18H
4 bytes of Mode Sense header
8 bytes of block descriptor
2 bytes of mode page header
12 bytes of Disconnect/Reconnect parameters
24H
4 bytes of Mode Sense header
8 bytes of block descriptor
2 bytes of mode page header
24 bytes of Format Device parameters
20H
4 bytes of Mode Sense header
8 bytes of Block descriptor
2 bytes of mode page header
20 bytes of Rigid Disc Geometry parameters
20H
4 bytes of Mode Sense header
8 bytes of block descriptor
2 bytes of mode page header
20 bytes of Caching parameters
24H
4 bytes of Mode Sense header
8 bytes of block descriptor
2 bytes of mode page header
24 bytes of Notch and Partition parameters
18H
4
8
2
12
bytes of Mode Sense header
bytes of block descriptor
bytes of mode page header
bytes of Power Condition parameters
ST3655 Family SCSI Drives Product Manual, Rev. A
Page
code
38H
3CH
00H
3FH
Allocation
length
55
Mode Sense data returned
1CH
4
8
2
16
bytes of Mode Sense header
bytes of block descriptor
bytes of mode page header
bytes of Cache Control parameters
0FH
4
8
2
3
bytes of Mode Sense header
bytes of block descriptor
bytes of mode page header
bytes of Soft ID parameters
10H
4
8
2
4
bytes of Mode Sense header
bytes of block descriptor
bytes of mode page header
bytes of Operating parameters
4 bytes of Mode Sense header
8 bytes of block descriptor
143 or 144 2 bytes of mode page header
143 or 144 bytes of mode parameters,
including all mode pages
* The allocation length depends on whether the Operating page has 2
or 3 bytes. The Operating page is described in Section C.10.
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.
Bit
Byte
7
6
5
4
3
2
0
Mode sense data length
1 (default)
Medium type (00H)
2
WP=0
3 (default)
1
0
Reserved
Block descriptor length (08H)
Block descriptor
4 (default)
Density code (00H)
5–7
Number of blocks
8 (default)
Reserved (00H)
9–11
Block length
Mode pages
12–n
Mode pages
Byte 0
The mode sense data length specifies the number of
bytes minus 1 of the Mode Sense data to be transferred
to the initiator.
Byte 1
The medium type is always 0.
Byte 2
The WP (write protect) bit is always 0, which means the
media is write-enabled.
Byte 3
The block descriptor length is the number of bytes in the
block descriptor. This value does not include the page
headers and mode pages that follow the block descriptor,
if any.
Byte 4
The density code is not supported.
Bytes 5–7
The number of blocks field contains the total number of
blocks available to the user, which is specified on page 1.
Byte 8
Reserved.
Bytes 9–11
The block length is specifies the number of bytes contained in each logical block described by the block descriptor.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
1
0
1
1
0
0
0
0
Immed
1
LUN = 0
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
Start
5
0
0
0
0
0
0
Flag
Link
Byte 1 If the immed bit is 0, the drive returns the status after it completes
the command. If the immed bit is 1, the drive returns the status
when it receives the command.
Byte 4 If the start bit is 1, the drive spins up. If the start bit is 0, the drive
spins down.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
Flag
Link
1
LUN = 0
2
0
0
0
3–4
Allocation length
5
Bytes 3–4
0
0
0
0
0
The allocation length specifies the number of bytes the
initiator has allocated for returned diagnostic result data. An
allocation length of 0 means that no diagnostic data is
transferred. Any other value indicates the maximum number of bytes to be transferred. The allocation length should
be at least 8 bytes to accommodate all the diagnostic data.
3.4.15.1 Diagnostic data format
Bit
Byte
7
6
5
4
3
2
0–1 (default)
Additional length (0006H)
2–5
FRU code
6
Diagnostic error code
7
Vendor-unique error code
1
0
Byte 0–1
The additional length indicates the number of additional
bytes included in the diagnostic data list. A value of 0000H
means that there are no additional bytes. A value of 0006H
means that no product-unique bytes are available.
Bytes 2–5
If the FRU (field replaceable unit) code is 00H, there is no
FRU information. If the FRU code is 01H, replace the drive.
Other values are drive-unique.
Byte 6
The diagnostic error code is not supported.
Byte 7
T he vendor-unique error codes are li ste d in Section 3.4.15.2.
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.
Error code
Description
01H
Format diagnostic error
02H
Microprocessor RAM diagnostic error
04H
No drive ready
08H
No sector or index detected
09H
Fatal hardware error during drive diagnostics
0CH
No drive command complete
10H
Unable to set drive sector size
14H
Unable to clear drive attention
18H
Unable to start spindle motor
20H
Unable to recall drive
30H
Unable to send write current data to drive
34H
Unable to issue the Seek command
40H
Unable to read user table from drive
41H
No more spare sectors during drive diagnostics
42H
Unable to read reallocation table
43H
Unable to read ETF log
60H
Thermal calibration failure
70H
Microprocessor internal timer error
80H
Buffer controller diagnostic error
81H
Buffer RAM diagnostic error
C1H
Data miscompare during drive diagnostics
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
1
1
1
0
1
0
0
Self
Test
Dev
OfL
Unit
OfL
0
0
0
0
0
Flag
Link
1
LUN = 0
2
0
0
0
0
3–4 (default)
5
Byte 1
0
Parameter list length (00H)
0
0
0
0
When the self test bit is 1, the drive performs the buffer RAM
diagnostics, which is the default self test. If the default self
test is requested, the parameter list length is 0 and no data
is transferred. If the self test passes successfully, the command terminates with a good status. If the self test fails, the
command terminates with a check condition status and the
sense key is hardware error.
The Dev OfL (device off line) bit is not supported.
The UnitOfL (unit off line) bit is not supported.
Bytes 3–4
The parameter list length is always zero. This byte is not
supported.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
0
0
1
0
1
0
0
0
0
Rel Adr
1
LUN
2–5
Logical block address
6
0
0
0
0
0
0
0
0
7
0
0
0
0
0
0
0
0
8
0
0
0
0
0
0
0
PMI
9
0
0
0
0
0
0
Flag
Link
Bytes 2–5
The logical block address specified in the CDB cannot be
greater than the logical block address reported by the drive
in the read capacity data.
Byte 8
If the partial medium indicator (PMI) bit is zero, the logical
block address in the CDB is also zero. The read capacity
data returned by the drive contains the logical block address
and block length of the last logical block of the drive.
If the PMI bit is one, the drive returns the read capacity data,
which contains the logical block address and block length
of the last logical block address, after which a substantial
delay (approximately 1 msec) in data transfer occurs. This
logical block address must be greater than or equal to the
logical block address specified in the command descriptor
block. This reported logical block address is a cylinder
boundary.
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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. For more information
about the reservation conflict status, see Section 3.2.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
0
1
0
0
0
DPO
FUA
0
0
Rel Adr
0
0
0
0
Flag
Link
1
LUN
2–5
6
Logical block address
0
0
0
7–8
9
Byte 1
0
0
Transfer length
0
0
0
0
0
If the DPO (disable page out) bit is one, the cached data
that the drive receives during this command has the lowest
priority for being retained in the cache. If DPO is zero, the
cached data has the highest priority for being retained in
the cache.
If the FUA (forced unit access) bit is one, the drive must
access the disc to get the data requested by the initiator,
even if the data is available in the cache. If the FUA bit is
zero, the drive can get the data from the cache or the disc.
If the REL ADR bit is one, the logical block address field
specifies the first logical block of the range of logical blocks
to be written and verified by the drive. If the REL ADR bit is
one, the logical block address field is a two’s complement
displacement. This displacement is added to the logical
block address last accessed on the drive to determine the
logical block address for this command. The REL ADR bit
should only be one if linked commands are used.
Bytes 2–5
The logical block address specifies the logical block where
the read operation begins.
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. This command is like the Write
command, except that the command descriptor block for this command
contains a 4-byte logical block address and a 2-byte transfer length. For
more information about the Write command, see Section 3.4.7.
If there is a reservation access conflict, this command terminates with a
reservation conflict status and no data is written. For more information
about the reservation conflict status, see Section 3.2.
Bit
Byte
7
0
0
1
6
5
0
1
LUN
2–5
6
Byte 1
3
2
1
0
0
1
0
1
0
DPO
FUA
0
0
Rel Adr
0
0
0
0
Flag
Link
Logical block address
0
0
0
7–8
9
4
0
0
Transfer length
0
0
0
0
0
If the DPO (disable page out) bit is one, the cached data
that the drive receives during this command has the lowest
priority for being retained in the cache. If DPO is zero, the
cached data has the highest priority for being retained in
the cache.
If the FUA (forced unit access) bit is one, the drive must
access the disc to write the data sent by the initiator, even
if the data could be stored in the cache. If the FUA bit is
zero, the drive can write the data to the cache or the disc.
If the REL ADR bit is one, the logical block address field
specifies the first logical block of the range of logical blocks
to be written and verified by the drive. If the REL ADR bit is
one, the logical block address field is a two’s complement
displacement. This displacement is added to the logical
block address last accessed on the drive to determine the
logical block address for this command. The REL ADR bit
should only be one if linked commands are used.
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.
3.5.4
Seek Extended command (2BH)
The Seek Extended command requests that the drive seek to the
specified logical block address. This command is the same as the Seek
command, except that the CDB includes a 4-byte logical block address.
The Seek command is described in Section 3.4.8.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
0
1
0
1
1
0
0
0
0
0
1
LUN
2–5
Logical block address
6
0
0
0
0
0
0
0
0
7
0
0
0
0
0
0
0
0
8
0
0
0
0
0
0
0
0
9
0
0
0
0
0
0
Flag
Link
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
0
1
1
1
0
0
0
0
BYT
CHK
REL
ADR
0
0
0
0
Flag
Link
1
LUN
2–5
6
Logical block address
0
0
0
7–8
9
Byte 1
0
0
Transfer length
0
0
0
0
0
If the BYT CHK (byte check) bit is zero, the drive verifies
the media without performing a byte-by-byte comparison of
the data stored there. If the BYT CHK bit is one, the drive
verifies the media and performs a byte-by-byte comparison
of the data stored there.
If the REL ADR bit is one, the logical block address field
specifies the first logical block of the range of logical blocks
to be written and verified by the drive. If the REL ADR bit is
one, the logical block address field is a two’s complement
displacement. This displacement is added to the logical
block address last accessed on the drive to determine the
logical block address for this command. The REL ADR bit
should only be one if linked commands are used.
Bytes 2–5
The logical block address field specifies the logical block
where the drive begins writing and verifying the data.
Bytes 7–8
The transfer length field specifies the number of contiguous
logical blocks to be transferred. If the transfer length is zero,
the initiator does not transfer any data and the drive does
not write or verify any data. This condition is not considered
an error.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
0
1
1
1
1
0
0
0
BYT
CHK
REL
ADR
0
0
0
0
Flag
Link
1
LUN
2–5
6
Logical block address
0
0
0
7–8
9
Byte 1
0
0
Verification Length
0
0
0
0
0
If the BYT CHK (byte check) bit is zero, the drive verifies
the media without performing a byte-by-byte comparison of
the stored data. If the BYT CHK bit is one, the drive verifies
the media and performs a byte-by-byte comparison of the
stored data.
A REL ADR bit of zero means that the logical block address
field specifies the first logical block of the range of logical
blocks to be written by the drive. If the REL ADR bit is one,
the logical block address field is a two’s complement displacement. This displacement is added to the logical block
address last accessed on the drive to determine the logical
block address for this command. The REL ADR bit should
only be one if linked commands are used.
Bytes 2–5
The logical block address field specifies the logical block
where the drive begins verifying the data.
Bytes 7–8
The verification length field specifies the number of contiguous logical blocks to be verified. If the verification length is
zero, the drive does not verify any logical blocks although
an implied seek is still performed. This condition is not
considered an error.
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. These lists are described in Section 3.4.4.1.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
1
0
1
1
1
0
0
0
0
0
1
LUN
2
0
0
0
P-list
G-list
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
0
0
6
0
0
0
0
0
0
0
0
0
Flag
Link
7–8
9
Byte 2
Defect list format
Allocation length
0
0
0
0
0
If the P-list bit is 1, the drive sends the primary defect list. If
the P-list bit is 0, the drive does not send the primary defect
list. If the G-list bit is 1, the drive sends the grown defect list.
If the G-list bit is 0, the drive does not send the grown defect
list. If both the P-list and G-list bits are zero, the drive returns
the defect list header only.
If the defect list format field contains 100, the drive returns
the defect data in the bytes-from-index format. If the defect
list format field contains 101, the drive returns the defect
data in the physical sector format. If the defect list format
field contains 000, the drive returns the defect data in the
default format, which is the physical sector format, and
generates a check condition status.
Bytes 7–8
The allocation length specifies the number of bytes the
initiator has allocated for the returned defect data. An
allocation length of 0 indicates that no defect data is transferred. Any other value indicates the maximum number of
bytes to be transferred. The data in phase ends when the
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
P-list
G-list
2–3
Byte 1
Defect list format
Defect list length
If the P-list bit is 1, the defect data contains the primary
defect list. If the P-list bit is 0, the defect data does not
contain the primary defect list.
If the G-list bit is 1, the defect data contains the grown defect
list. If the G-list bit is 0, the defect data does not contain the
grown defect list.
The defect list format field is described in Section 3.5.7.
Bytes 2–3
The defect list length specifies the length of the defect data.
If the P-list and G-list bits are 0, no defect descriptor bytes
are sent to the initiator and the defect list length is 0. If the
allocation length (in the CDB) is not large enough to accommodate all the defect descriptors, the defect list length
contains the same value as the allocation length.
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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. (Mode
Page 08H is described in Section C.5.)
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
1
1
0
1
1
0
0
1
LUN
Buffer ID (00H)
2
3–5
Buffer offset
6–8
Parameter list length
9
Mode
0
0
0
0
0
0
Flag
Link
Byte 1 If the mode bits contain 000, the initiator transfers data to the
drive buffer with a 4-byte header that contains all zeros. This
mode is called write combined header and data.
If the mode bits contain 010, the initiator transfers data to the
drive buffer without the header. This mode is called write data.
If the mode bits contain 101, the initiator downloads microcode
to the drive buffer, and the drive saves the microcode in reserved
cylinders. The drive uses the new microcode for all future
operations. This mode is called download microcode and save.
Note. If the mode bits contain 101, the flag and link bits must
be 0.
After the microcode has been successfully downloaded, the
drive generates a unit attention condition of microcode has been
downloaded for all initiators except the one that issued the
current Write Buffer command.
All other settings for the mode bits are reserved.
Byte 2 The buffer ID is not supported and must always be zero.
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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.
Bytes 6–8
The parameter list length field specifies the maximum number of bytes the initiator transfers. If it transfers the 4-byte
header, the transfer length includes the header. If the
transfer length is zero, no data is transferred to the drive
buffer. This is not considered an error.
3.5.9
Read Buffer command (3CH)
In conjunction with the Write Buffer command, the Read 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.
Note. This command treats the buffer as a single segment, regardless
of the number of segments specified in Mode Page 08H. (Mode
Page 08H is described in Section C.5.)
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
1
1
1
0
0
0
0
1
LUN
Buffer ID (00H)
2
3–5
Buffer offset
6–8
Allocation length
9
Byte 1
Mode
0
0
0
0
0
0
Flag
Link
If the mode bits contain 000, the initiator reads data from
the drive buffer. The data is preceded by a 4-byte header.
This mode is called read combined header and data.
If the mode bits contain 010, the initiator reads data from
the drive buffer without a header. This mode is called read
data.
All other settings for the mode bits are reserved.
Byte 2
The buffer ID is not supported and must always be zero.
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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.
Bytes 6–8
The allocation length field specifies the maximum number
of bytes read by the initiator. If the 4-byte header is transferred, the transfer length includes the header. If the transfer
length is zero, no data is read. This is not considered an
error.
3.5.9.1
Bit
Byte
Read Buffer header
7
6
5
4
3
0
0
1–3
Buffer capacity
Bytes 1–3
2
1
0
The buffer capacity field specifies the size of the drive
buffer.
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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.
Bytes 7–8
The byte transfer length specifies the number of bytes
transferred to the initiator. The drive transfers either the byte
transfer length or the logical block size plus six, whichever
is less. If the byte transfer length is zero, the drive does not
transfer any data to the initiator. This condition is not
considered an error.
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.
Bit
Byte
7
6
5
4
3
2
1
0
0
0
0
1
1
1
1
1
1
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 writing data.
Bytes 7–8
The byte transfer length specifies the number of bytes
transferred by the initiator to the drive. If the transfer length
does not equal the sum of the logical block size plus six, the
command is terminated with a check condition status. If the
byte transfer length is zero, the initiator does not transfer
any data to the drive; this condition is not considered an
error.
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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. If the drive receives a Group 5 command, it returns
a check condition status. Group 6 commands are reserved for Seagate
use.
Note. Do not use Group 6 commands. If you do, you may destroy data
on the disc.
3.8
Group 7 commands
Group 7 commands are 10-byte commands. These commands are not
implemented. If the drive receives one of these commands, it returns a
check condition status.
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.
Code
Message name
Must
negate ATN
Direction
before last
ACK?
06H
Abort
O
Yes
0DH
Abort tag
O
Yes
0CH
Bus device reset
O
Yes
0EH
Clear queue
O
Yes
00H
Command complete
I
—
04H
Disconnect
I
—
80H
Identify
I/O
No
23H
Ignore wide residue
I
—
0FH
Initiate recovery
I/O
Yes
05H
Initiator detected error
O
Yes
0AH
Linked command complete
I
—
0BH
Linked command complete
(with flag)
I
—
09H
Message parity error
O
Yes
07H
Message reject
I/O
Yes
08H
No operation
O
Yes
21H
Head of queue tag
O
No
22H
Ordered queue tag
O
No
20H
Simple queue tag
O
No
10H
Release recovery
O
Yes
03H
Restore pointers
I
—
02H
Save data pointer
I
—
11H
Terminate I/O process
O
Yes
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. If any problem
precludes the successful exchange of synchronous data transfer request
messages, the initiator and drive default to asynchronous data transfers.
This exchange of messages establishes the transfer period and the
REQ/ACK offset.
Bit
Byte
7
6
5
4
3
2
1
0
Extended message (01H)
1
Extended message length (03H)
2
Identifier code (01H)
3
Minimum transfer period divided by 4
4
REQ/ACK offset
0
Byte 0 This byte identifies the message as an extended message.
Byte 1 This byte reports the length of the message.
Byte 2 This byte identifies the message as a synchronous data transfer
request message.
Byte 3 The value contained in this byte is in nanoseconds. It is equal to
the minimum time between leading edges of successive REQ
and ACK pulses divided by four. In byte 3, the minimum value
supported by the drive is 25, which is equivalent to a transfer
period of 100 nanoseconds, or an external transfer rate of
10 Mbytes per second. A value of 50 is equivalent to a transfer
period of 200 nanoseconds, or an external transfer rate of
5 Mbytes per second.
Byte 4 The REQ/ACK offset is the maximum number of REQ pulses
that may be outstanding before its corresponding ACK pulse is
received at the target. A REQ/ACK offset of zero indicates
asynchronous mode. The drive supports a maximum REQ/ACK
offset of six.
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.
Bit
Byte
7
0
Valid
6
5
4
3
2
1
0
0
0
X
Error code
1
1
1
1
0
Segment number (00H)
2
0
0
ILI
0
Sense key
3–6
Information bytes
7
Additional sense length
8–11
Command specific data
12
Additional sense code
13
Additional sense code qualifier
14
FRU code
15
SKSV
16–17
18–22
Sense key specific
Product-unique sense data (00H)
Byte 0 If the valid bit is one, the information bytes (bytes 3 through 6)
are valid. If the validity bit is zero, the information bytes are not
valid.
If the error code contains a value of 70H, the error occurred on
the command that is currently pending. If the error code contains
a value of 71H, the error occurred during the execution of a
previous command for which a good status has already been
returned.
Byte 1 The segment number is always zero.
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.
Bytes 3–6
When the valid bit is 1, the information bytes contain the
logical block address of the current logical block associated with the sense key. For example, if the sense key is
media error, the information bytes contain the logical
block address of the offending block.
Byte 7
The additional sense length is limited to a maximum of
0EH additional bytes. If the allocation length of the command descriptor block is too small to accommodate all of
the additional sense bytes, the additional sense length is
not adjusted to reflect the truncation.
Bytes 8–11
These bytes contain command specific data.
Bytes 12–13 The additional sense code and additional sense code
qualifier provide additional details about errors. See Appendix B.3.
Byte 14
The field replaceable unit (FRU) code is used by field
service personnel only.
Bytes 15–22 These bytes are not used.
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.
1H
Recovered error. The drive completed the last
command successfully with some recovery action.
When many recovered errors occur during one
command, the drive determines which error it will
report.
2H
Not ready. The addressed logical unit cannot be
accessed. Operator intervention may be required to
correct this condition.
3H
Medium error. The command was terminated with a
nonrecoverable error condition, probably caused by a
flaw in the media or an error in the recorded data.
4H
Hardware error. The drive detected a nonrecoverable
hardware failure while performing the command or
during a self-test. This includes, for example, SCSI
interface parity errors, controller failures and device
failures.
5H
Illegal request. An illegal parameter in the command
descriptor block or in the additional parameters
supplied as data for some commands (for example, the
Format Unit command, the Mode Select command and
others). If the drive detects an invalid parameter in the
command descriptor block, it terminates the command
without altering the media. If the drive detects an
invalid parameter in the additional parameters supplied
as data, the drive may have already altered the media.
6H
Unit attention. The drive may have been reset. See
the Seagate SCSI-2 Interface Manual, publication
number 77765466, for more details about the Unit
Attention condition.
BH
Aborted command. The drive aborted the command.
The initiator may be able to recover by retrying.
EH
Miscompare. The source data did not match the data
read from the media.
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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.
03
00
A write fault occurred.
04
00
The drive is not ready and the cause is not
reportable.
04
01
The drive is not ready, but it is in the process
of becoming ready.
04
02
The drive is not ready; it is waiting for the
initializing command.
04
03
The drive is not ready; human intervention is
required.
04
04
The drive is not ready; the format routine is in
process.
05
00
The drive does not respond when it is selected.
06
00
Track 0 was not found.
07
00
More than one drive is selected at a time.
08
00
There was a drive communication failure.
08
01
A drive communication time-out occurred.
08
02
A drive communication parity error occurred.
09
00
A track following error occurred.
0A
00
An error log overflow occurred.
0C
01
A write error occurred, but the error was
recovered using auto-reallocation.
0C
02
A write error occurred. Auto-reallocation was
attempted, but it failed.
10
00
An ID CRC or ECC error occurred.
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.
14
01
No record was found.
15
00
A seek positioning error occurred.
15
01
A mechanical positioning error occurred.
15
02
A positioning error was detected by reading
the media.
16
00
A data synchronization mark error occurred.
17
00
The data was recovered without applying error
correction or retrying.
17
01
The data was recovered with retries.
17
02
The data was recovered with positive head
offset.
17
03
The data was recovered with negative head
offset.
17
05
The data was recovered using the previous
sector ID.
17
06
The data was recovered without ECC. The
drive uses data auto-reallocation.
18
00
The data was recovered with ECC.
18
01
The data was recovered with ECC and retries.
18
02
The data was recovered with ECC, retries,
and auto-reallocation.
19
00
There is an error in the defect list.
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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.
1D
00
During a verify operation, a compare error
occurred: the source data did not match the
data read from the media.
1E
00
An ID error was recovered.
20
00
The drive received an invalid command
operation code.
21
00
The logical block address was not within the
acceptable range.
22
00
The drive received a CDB that contains an
invalid bit. (This error code applies to directaccess devices.)
24
00
The drive received a CDB that contains an
invalid bit. (This error code applies to all SCSI
devices.)
25
00
The drive received a CDB that contains an
invalid LUN.
26
00
The drive received a CDB that contains an
invalid field.
26
01
The drive received a CDB containing a
parameter that is not supported.
26
02
The drive received a CDB containing an
invalid parameter.
26
03
The drive received a CDB containing a
threshold parameter that is not supported.
29
00
A power-on reset or a bus device reset
occurred.
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.
31
00
The media format is corrupted.
31
01
The format command failed.
32
00
There are no spare defect locations available.
32
01
An error occurred when the defect list was
being updated.
37
00
A rounded parameter caused an error.
3D
00
The identify message contains invalid bits.
3F
00
The target operation command was changed.
3F
01
The microcode was changed.
3F
02
The drive was operating as a SCSI drive and
is now operating as a SCSI-2 drive, or vice
versa.
3F
03
The inquiry data was changed.
40
00
The RAM failed.
40
8x
A correctable ECC error occurred; x equals
the length of the error.
40
90
A configuration error occurred.
40
A0
The self-test routine discovered an error in a
ROM.
40
A1
The self-test routine discovered an error in the
processor RAM.
40
A2
The self-test routine discovered an error in the
buffer RAM.
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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.
40
A9
The EEPROM directory cannot be read, or it is
corrupted.
40
AA
The EEPROM contains an incompatible
version number.
40
AB
The EEPROM contains an incompatible
revision number.
40
AC
An EEPROM checksum error occurred.
40
AD
The EEPROM contains invalid parameters.
40
AE
The EEPROM is incompatible with the HDA
and the circuit board. The EEPROM must be
reconfigured.
40
B0
The servo command timed out.
40
B1
The servo command failed.
40
B2
The servo command was rejected.
40
B3
The servo interface does not work.
40
B4
The servo either failed to lock on track during
spinup, or has wandered off track.
40
B5
An internal servo error occurred.
40
B6
During spinup, a servo error occurred.
40
B7
The servo pattern is inconsistent.
40
B8
A seek recovery error occurred.
40
B9
The actuator did not achieve high-speed
calibration.
40
C0
The defect list is full.
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.
43
00
A message reject error occurred.
44
00
An internal controller error occurred.
45
00
An error occurred during a selection or a
reselection.
47
00
A SCSI interface bus parity error occurred.
48
00
The initiator has detected an error.
49
00
The initiator received an invalid message from
the drive.
4C
00
Drive failed to self-configure.
4E
00
The drive attempted to perform overlapped
commands.
5B
00
There was a log exception.
5B
01
A threshold condition was met.
5B
02
The log counter has reached its maximum
value.
5B
03
All the log list codes have been used.
5C
00
There was a change in the RPL status. The
drive lost synchronization.
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. The default values contained in this appendix may differ from the
default values actually contained in your drive. To determine the
default values, use the Mode Sense command.
Page code
Bytes
Contains
changeable
parameters
Error Recovery page
01H
10
Yes
Disconnect/Reconnect page
02H
14
Yes
Format Device page
03H
22
Yes
Rigid Disc Geometry page
04H
22
Yes
Caching page (SCSI-3)
08H
18
Yes
Control Mode page
0AH
10
Yes
Notch page
0CH
22
No
Cache Control page
38H
14
No
Soft ID page
3CH
1
Yes
Operating page
00H
2 or 3
Yes
Mode page
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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.
• During the Mode Sense command, the PS (parameter savable) bit
is 1, which means the mode page is saved on the disc. During the
Mode Select command, you must set the PS bit to 0.
• An X means that the value of the bit cannot be specified. For example,
the default value of bit 0 of byte 1 of page 00H (the Operating Page)
cannot be specified because the bit can be either 1 or 0.
All mode pages contain a 2-byte header that contains the page code and
the page length for that particular page. The header is shown below.
Bit
Byte
7
0
PS
changeable
1
6
5
4
3
2
1
0
0
0
0
Page code
0
0
0
0
1
Page length
changeable
00H
Byte 0 During the Mode Sense command, the PS (parameter savable)
bit is 1, which means the mode page is saved on the disc. During
the Mode Select command, you must set the PS bit to 0.
The page code is the unique code that identifies the page.
Byte 1 The page length is the length, in bytes, of the page.
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.
Bit
Byte
7
0
PS (1)
6
5
3
2
1
0
Page code (01H)
1
2
4
Page length (0AH)
AWRE ARRE
TB
RC EER PER DTE DCR
default
0
0
0
0
0
0
0
0
changeable
1
1
1
1
1
1
1
1
3 (default)
Read retry count (20H)
changeable
FFH
4 (default)
Correction span (16H)
changeable
00H
5 (default)
Head offset count (00H)
changeable
00H
6 (default)
Data strobe offset count (00H)
changeable
00H
7 (default)
Reserved (00H)
changeable
00H
8 (default)
Write retry count (20H)
changeable
00H
9 (default)
Reserved (00H)
changeable
00H
10–11 (default)
Recovery time limit (FFFFH)
changeable
0000H
Byte 2 When the Automatic Write Reallocation Enabled (AWRE) bit
is 1, the drive automatically reallocates bad blocks detected
while writing to the disc. When the AWRE bit is 0, the drive does
not perform automatic reallocation; instead, the drive reports a
check condition status with a sense key of media error.
Note. The AWRE bit does not apply during the Format command.
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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. When the TB bit is 0, the failing
data block is not transferred.
When the Read Continuous (RC) bit is 1, the drive sends
all data without doing any corrections. This function supersedes other bits in this byte. When the RC bit is 0, the
correction is performed according to the other bits in this
byte.
When the Enable Early Recovery (EER) bit is 1, the drive
retries the command before applying ECC. When the EER
bit is 0, the drive applies ECC immediately. This bit applies
to data error recovery only; it does not affect positioning
retries and message system error recovery procedures.
When the Post Error (PER) bit is 1, the drive reports the
check condition status and the appropriate sense key for
any recovered errors encountered. When the PER bit is 0,
any errors recovered within the limits established by the
other error recovery flags are not reported. Any nonrecoverable errors are reported.
The Disable Transfer on Error (DTE) bit is valid only when
the PER bit is set to 1. When the DTE bit is 1, the drive
terminates data transfer if a recoverable error occurs. When
the DTE bit is 0, the drive continues transferring data if
recoverable errors are encountered.
When the Disable Correction (DCR) bit is 1, the drive does
not apply ECC to the data even if correction is possible.
Byte 3
The read retry count field is the maximum number of times
the drive attempts its recovery algorithms. If the EER bit
is 1, the number of retries specified by read retry count (up
to a maximum of nine retries) is performed before ECC is
applied. The read retry count field has a range of 0
through 20H. A read retry count of 0 means that no retries
are performed.
Byte 4
The correction span is the size of the largest read data error,
in bits, on which ECC correction is attempted. Longer errors
are reported as nonrecoverable.
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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. The write retry count field has a
range of 0 through 20H. A write retry count of 0 means
that no retries are performed.
Byte 9
Reserved.
Bytes 10–11 The recovery time limit field always has a value of FFFFH,
which means that the recovery time is unlimited.
C.2 Disconnect/Reconnect page (02H)
The Disconnect/Reconnect page is shown below. This table summarizes
the function, the default value, and the changeability of each bit.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
Page code (02H)
1
Page length (0EH)
2 (default)
Buffer full ratio (F0H)
changeable
FFH
3 (default)
Buffer empty ratio (10H)
changeable
FFH
4–5 (default)
Bus inactivity limit (000AH)
changeable
0000H
6–7 (default)
Disconnect time limit (0000H)
changeable
0000H
8–9 (default)
Connect time limit (0000H)
changeable
0000H
10–11 (default)
Maximum burst size (0000H)
changeable
0000H
12–15 (default)
Reserved (00000000H)
changeable
0000H
1
0
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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. This parameter is the numerator of a
fraction that has 256 as its denominator.
Bytes 4–5
The bus inactivity limit field indicates the time, in 100-µsec
increments, that the drive can assert the Busy signal
without handshakes until it disconnects. The drive may
round down to its nearest capable value. The default value
of 000AH allows the drive to maintain the BSY– signal for
1 msec without handshakes.
Bytes 6–7
The disconnect time limit field indicates the minimum
time, in 100-µsec increments, the drive remains disconnected until it attempts to reconnect. A value of 0 indicates
that the drive is allowed to reconnect immediately.
Bytes 8–9
The connect time limit field indicates the maximum time,
in 100-µsec increments, that the drive should remain
connected until it attempts to disconnect. The drive may
round to its nearest capable value. A value of 0 means
that the drive can remain connected indefinitely until it
tries to disconnect.
Bytes 10–11 The maximum burst size field limits the amount of data
that can be transferred during the data phase before the
drive disconnects from the host. The value, multiplied by
512, indicates the maximum number of bytes that can be
contained in a single burst. A value of 0 means that there
is no limit to how many bytes can be transferred during a
single burst.
Bytes 12–15 Reserved.
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.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
Page code (03H)
1
Page length (16H)
2–3
Tracks per zone
default
ST3285N and ST3390N = 0003H
ST3550N and ST3655N = 0005H
changeable
FFFFH
4–5 (default)
Alternate sectors per zone (0001H)
changeable
FFFFH
6–7 (default)
Alternate tracks per zone (0000H)
changeable
0000H
8–9
Alternate tracks per volume
default
ST3285N and ST3390N = 0006H
ST3550N and ST3655N = 000AH
changeable
FFFFH
10–11 (default)
Sectors per track (0052H)
changeable
0000H
12–13 (default)
Data bytes per physical sector (0200H)
changeable
0000H
14–15 (default)
Interleave (0001H)
changeable
0000H
16–17 (default)
Track skew factor (0002H)
changeable
FFFFH
18–19 (default)
Cylinder skew factor (0009H)
changeable
FFFFH
continued
0
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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. If each zone is treated as containing one
track, the valid value for tracks per zone is 1. If each zone is
treated as containing one cylinder, the valid value is equal
to the number of read/write heads.
Bytes 4–5
The alternate sectors per zone field indicates the number
of spare sectors to be reserved at the end of each defectmanagement zone. The drive defaults to one spare sector
per zone. If each zone is treated as containing one track,
the valid value for alternate sectors per zone is 1. If each
zone is treated as containing one cylinder, the valid values
are 1 through 3.
Bytes 6–7
The alternate tracks per zone field indicates the number
of spare tracks the drive reserves at the end of each
defect-management zone. A value of 0 indicates that no
spare tracks are reserved at the end of each zone for
defect management.
Bytes 8–9
The alternate tracks per volume field indicates the number
of spare tracks to be reserved at the end of the drive for
defect management.
For the ST3285N and ST3390N, the value must be a
multiple of 3 and can range from 3 through 255. For the
ST3550N and ST3655N, the value must be a multiple of
5 and can range from 5 through 255.
The default is equal to twice the number of read/write
heads.
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.
Bytes 14–15 The interleave field is the interleave value sent to the drive
during the last Format Unit command. This field is valid
only for Mode Sense commands. The drive ignores this
field during Mode Select commands. The interleave is
always 1:1.
Bytes 16–17 The track skew factor field indicates the number of physical sectors on the media between the last logical block of
one track and the first logical block of the next sequential
track of the same cylinder. The actual track skew factor
being used by the drive is different for every zone. The
default value is 0002H which is the track skew factor for
the first zone. This default value is only used when tracks
per zone and alternate sectors per zone are set to 1.
If the initiator attempts to change the value of the track
skew factor, the drive responds with a good status. However, the initiator cannot directly change the track skew
factor.
Bytes 18–19 The cylinder skew factor field indicates the number of
physical sectors between the last logical block of one
cylinder and the first logical block of the next cylinder. The
actual cylinder skew factor that the drive uses depends
on the zone. The default value is 0009H, which is the
cylinder skew factor for the first zone.
If the initiator attempts to change the value of the cylinder
skew factor, the drive responds with a good status. However, the initiator cannot directly change the cylinder skew
factor.
98
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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.
The Removable Media (RMB) bit is always set to 0,
indicating that the drive does not support removable
media. This same bit is also returned in the Inquiry parameters.
The Surface Map (SURF) bit is set to 0, indicating that the
drive allocates successive logical blocks to all sectors
within a cylinder before allocating logical blocks to the
next cylinder.
Bytes 21–23 Reserved.
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.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (04H)
1
Page length (16H)
2–4
Number of cylinders
changeable
000000H
5
Number of heads
changeable
00H
6–8
Starting cylinder for write precompensation
default
000000H
changeable
000000H
9–11
Starting cylinder for reduced write current
default
000000H
changeable
000000H
12–13 (default)
Drive step rate (0000H)
changeable
0000H
14–16 (default)
Loading zone cylinder (000000H)
changeable
000000H
17
default
changeable
18 (default)
RPL
Reserved
0
0
0
0
0
0
Rotational offset (00H)
changeable
FFH
19 (default)
Reserved (00H)
changeable
00H
20–21
Media rotation rate
default
1194H
changeable
0000H
22–23 (default)
Reserved (0000H)
changeable
0000H
0
0
1
1
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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.
Bytes 6–16
The starting cylinder for reduced write current, starting
cylinder for reduced read current, drive step rate, and
loading zone cylinder bytes are not used by the drive.
Byte 17
When the Rotational Position Locking (RPL) bits are
00Binary, the rotational position locking is changeable.
When the RPL bits are 01Binary, the drive automatically
synchronizes its spindle with the synchronized master.
When the RPL bits are 10Binary or 11Binary, the drive is the
synchronized-spindle master.
For more information about external spindle-clock synchronization, see Section 2.11.
Byte 18
The rotational offset is the rotational skew the drive uses
when synchronized. The rotational skew is applied in the
retarded direction (lagging the sync spindle master). A
value of zero means no rotational offset is used.
Byte 19
Reserved.
Bytes 20–21 The medium rotation rate is the spindle speed, which is
specified on page 1.
Bytes 22–23 Reserved.
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. Because these sectors are read
before they are requested, access read time for the sectors is virtually
eliminated. This process is called either read look-ahead or read caching.
Read look-ahead and caching are similar algorithms. Read look-ahead
occurs when a Read command requests more data than can be contained in one buffer segment. Caching occurs when a Read command
requests less data than can be contained in one buffer segment.
The buffer used for read look-ahead and caching can be divided into
segments as shown in the following table. To change the number of
segments, use byte 13 of the Caching page, which is described in
Appendix C.5.3. The default is one, 256-Kbyte segment.
Number of segments
Size of segment (in Kbytes)
1
256
2
128
4
64
8
32
16
16
When the buffer is divided into multiple segments, each segment functions as an independent buffer, causing dramatically increased performance in multitasking and multiuser environments.
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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.5.3 Caching page description
The Caching page is shown below. This table summarizes the function,
the default value and the changeability of each bit.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (08H)
1
Page length (12H)
2
IC
MF
RCD
default
1
ABPF CAP DISC SIZE WCE
0
0
1
0
1
0
0
changeable
1
0
1
0
1
1
1
1
Demand read
retention priority
3
Write retention priority
default
0
0
0
0
0
0
0
0
changeable
0
0
0
0
0
0
0
0
4–5 (default)
Disable prefetch transfer length (FFFFH)
changeable
0000H
6–7 (default)
Minimum prefetch (0000H)
changeable
0000H
8–9 (default)
Maximum prefetch (FFFFH)
changeable
FFFFH
10–11 (default)
Maximum prefetch ceiling (FFFFH)
changeable
FFFFH
12
FSW Rsrvd DRA
Reserved
default
1
0
0
0
0
0
0
0
changeable
1
0
1
0
0
0
0
0
ST3655 Family SCSI Drives Product Manual, Rev. A
Bit
Byte
7
6
13
5
4
3
103
2
1
0
Number of cache segments
default
0
0
0
0
0
0
0
1
changeable
1
1
1
1
1
1
1
1
14–15 (default)
Cache segment size (0000H)
changeable
0000H
16 (default)
Reserved (00H)
changeable
00H
17–19 (default)
Noncache segment size (000000H)
changeable
000000H
Byte 2 When the Initiator Control (IC) bit is 1, the drive uses either the
number of cache segments field or the cache segment size field,
as determined by the SIZE bit (bit 3), to control the caching
algorithm. When the IC bit is 0, the drive uses its own algorithm
to control caching.
When the Abort Prefetch (ABPF) bit is 0, the drive controls
completion of prefetch. See the description for the DISC bit,
below. This is the default value and it is not changeable.
When the Caching Analysis Permitted (CAP) bit is 0, caching
analysis is disabled to reduce overhead time or to prevent
operations that are not pertinent from impacting tuning values.
When the CAP bit is 1, caching analysis is enabled.
When the Discontinuity (DISC) bit is 1, the drive may prefetch
across cylinder boundaries, where head seeks consume additional processing time. This is the default value and it is not
changeable.
When the Size Enable (SIZE) bit is 0, the drive uses the number
of cache segments field to control caching segmentation. When
the SIZE bit is 1, the drive uses the cache segment size field to
control caching segmentation.
When the Write Cache Enable (WCE) bit is 0, the drive returns
a good status for a Write command after successfully writing all
the data to the media. When the WCE bit is 1, the drive returns
a good status for a Write command after successfully receiving
the data and before writing it to the media.
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.
When the Read Cache Disable (RCD) bit is 0, the drive
may return data requested by a Read command by accessing either the cache or the media. If the RCD bit is 1,
the cache is not used.
Byte 3
The demand read retention priority field is not used. The
initiator cannot assign any special retention priority to the
drive.
The write retention priority field is not used. The initiator
cannot assign any special retention priority to the drive.
Bytes 4–5
The disable prefetch transfer length always has a value
of FFFFH, which means that the drive attempts an anticipatory prefetch for all Read commands.
Bytes 6–7
The minimum prefetch field specifies the minimum number of blocks the drive prefetches, regardless of the delays
it may cause in executing subsequent pending commands. When the minimum prefetch field contains 0, the
drive terminates prefetching whenever another command
is ready to be executed. If the minimum prefetch equals
the maximum prefetch, the drive prefetches the same
number of blocks regardless of whether there are commands pending.
Bytes 8–9
The maximum prefetch field specifies the maximum number of blocks the drive prefetches during a Read command if there are no other commands pending. The
maximum prefetch field represents the maximum amount
of data to prefetch into the cache for any single Read
command.
Bytes 10–11 The maximum prefetch ceiling field should be equal to the
maximum prefetch field. The maximum prefetch ceiling
and maximum prefetch fields are the same if the MF bit
is 0.
Byte 12
When the Force Sequential Write (FSW) bit is 1, the drive
writes blocks of data to the media sequentially, from
lowest to highest logical block address. When the FSW
bit is 0, the drive changes the sequence in which it writes
logical blocks to speed processing.
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.
Bytes 14–15 The cache segment size field indicates the segment size
in bytes. The cache segment size field is valid only when
the SIZE bit is 1.
Byte 16
Reserved.
Bytes 17–19 The noncache segment size field always contains zeros.
This means that the entire buffer is available for caching.
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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.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (0AH)
1
Page length (0AH)
2
Reserved
RLEC
default
0
0
0
0
0
0
0
0
changeable
0
0
0
0
0
0
0
1
QErr
DQue
0
0
3
default
Queue
algorithm modifier
Reserved
0
0
0
0
0
changeable
0
00H
4
EECA
default
0
Reserved
0
0
0
RAENP UAAENP EAENP
0
changeable
00H
0
0
5 (default)
Reserved (00H)
changeable
00H
6–7 (default)
Ready AEN hold-off period (0000H)
changeable
0000H
8–9 (default)
Busy timeout period (FFFFH)
changeable
0000H
10–11
(default)
Reserved (0000H)
changeable
0000H
0
Byte 2
The RLEC bit is not implemented.
Byte 3
The queue algorithm modifier field contains zero, which
means the drive arranges the execution sequence of the
commands using a simple queue tag.
The disable queuing (DQue) bit is zero, which means that
tagged command queuing is enabled.
Byte 4
Not implemented.
Byte 5
Reserved.
Bytes 6–7
Not implemented.
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.
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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.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (0CH)
1
Page length (16H)
2
ND
LPN
Reserved
default
1
0
0
0
0
0
0
0
changeable
0
0
0
0
0
0
0
0
3 (default)
Reserved (00H)
changeable
(00H)
4–5
Maximum number of notches
default
ST3285N, ST3390N, ST3550N = 13H
ST3655N = 12H
changeable
0000H
6–7 (default)
Active notch (0000H)
changeable
0
0
0
1
1
1
8–11 (default)
Starting boundary (00000000H)
changeable
00000000H
1
12–15
Ending boundary
default
ST3285N, ST3390N, ST3550N = 000A7602H
ST3655N = 0009BC04H
changeable
00000000H
16–23 (default)
Pages notched (0000000000000008H)
changeable
0000000000000000H
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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.
Bytes 4–5
The maximum number of notches field indicates the maximum number of notches supported by the drive.
Bytes 6–7
The active notch field identifies the notch to which this,
and all future Mode Select and Mode Sense commands
refer, until the active notch is changed by a later Mode
Select command. The value of the active notch field must
be greater than or equal to 0 and less than or equal to the
maximum number of notches. An active notch value of 0
means that current and future Mode Select and Mode
Sense commands refer to the parameters that apply for
all notches.
Bytes 8–11
The starting boundary field indicates the beginning of the
active notch, if the active notch is not 0, or the starting
boundary of the logical unit, if the active notch is 0. This
field is ignored by the Mode Select command.
When the LPN bit is 0, the three most significant bytes
represent the cylinder number and the least significant
byte represents the head number.
Bytes 12–15 The ending boundary field indicates the end of the active
notch, if the active notch is not 0, or the end of the logical
unit, if the active notch is 0. The default is equal to the end
of zone 1.
When the LPN bit is 0, the three most significant bytes
represent the cylinder number and the least significant
byte represents the head number.
Bytes 16–23 The pages notched field contains a bit map of the mode
page codes that indicates which pages may contain different parameters for each notch. When a bit is 1, the
corresponding mode page can contain different parameters for each notch. When a bit is 0, the corresponding
mode page contains the same parameters for all the
notches. The most significant bit of this field corresponds
to page code 3FH and the least significant bit corresponds
to page code 00H.
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.
Bit
Byte
7
0
PS (1)
6
default
4
3
2
1
0
Page code (38H)
1
2
5
Page length (0EH)
Rsrvd WIE Rsrvd
0
X
0
CE
X
Cache table size
X
X
changeable
(00H)
3 (default)
Prefetch threshold (00H)
changeable
00H
4 (default)
Maximum prefetch (FFH)
changeable
00H
5 (default)
Maximum prefetch multiplier (00H)
changeable
00H
6 (default)
Minimum prefetch (00H)
changeable
00H
7 (default)
Minimum prefetch multiplier (00H)
changeable
00H
8–15 (default)
Reserved (0000000000000000H)
changeable
0000000000000000H
X
X
Byte 2 The cache enable (CE) bit is always the inverse of the RCD bit
in Mode Page 08H.
The write index enable (WIE) bit controls the creation of cache
data on Write commands. If bit 6 is 0, the next command treats
the cache area as empty.
The cache table size field contains the same values as Mode
Page 08H, byte 13, bits 3 through 0.
Byte 3 The prefetch threshold is not implemented. The drive reads until
the buffer is full upon receipt of a Read command.
Byte 4 The maximum prefetch field always contains the same value as
byte 9 of the Caching page. The initiator cannot directly change
this byte.
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. The initiator
cannot directly change this byte.
Byte 8–15
Reserved.
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. When the write life cycle limit is
exceeded, the drive sets the sense key to hardware error and the
additional sense error code to C2H. The additional sense error
codes are described in Appendix B.3.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (3CH)
1
Page length (01H)
2
Soft
ID
Soft Param Soft Remote
ID 2 ID 1
Parity enable remote
S/S
default
0
0
0
0
0
0
0
0
changeable
1
1
1
1
1
1
1
1
ID 0
Byte 2 When the soft ID bit is 0, the drive ignores ID0, ID1 and ID2 and
uses the SCSI ID jumpers to determine the SCSI ID. When the
soft ID bit is 1, the drive ignores the SCSI ID jumpers and uses
ID0, ID1 and ID2 to determine the SCSI ID. See Figure 7 on page
25 for jumper settings.
When the soft parity bit is 0, the drive uses the parity jumper
settings to determine whether the drive uses parity. When the
soft parity bit is 1, the drive ignores the parity jumper settings.
When the soft remote bit is 0, the drive uses the remote start
jumper setting to determine whether remote start is implemented. When the soft remote bit is 1, the drive ignores the
jumpers and uses the remote S/S bit to determine whether
remote start is implemented.
When the remote S/S bit is 0, the drive spins up after a delay
specified by the spinup delay field (byte 4 of the Operating page,
00H). When the remote S/S bit is 1, the drive spins up when it
receives the Start Unit command. This bit is only valid if the soft
remote bit is 1.
The ID0, ID1 and ID2 bits are the SCSI ID bits. These bits are
only valid when the soft ID bit is 1.
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. If the length is two bytes, then byte 4, the spinup delay field, is not
written and is assumed to be unchanged.
In addition to being saved on the media, this vendor-unique 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. When the write life cycle limit is
exceeded, the drive sets the sense key to hardware error and the
additional sense error code to C2H. The additional sense error
codes are described in Appendix B.3.
Bit
Byte
7
0
PS (1)
6
5
4
3
2
1
0
Page code (00H)
Page length (02H or 03H)
1 (default)
default
0
0
0
0
0
0
1
X
changeable
0
0
0
0
0
0
0
1
2
Usage SSM RSVD ATOFF
Reserved
default
1
0
0
0
0
0
0
0
changeable
1
1
0
1
0
0
0
0
3
Rsrvd
default
0
0
0
0
0
0
0
0
changeable
0
1
1
1
1
1
1
1
Device type qualifier (00H)
4 (default)
Spinup delay (00H)
changeable
FFH
Byte 2 When the usage bit is 1, a warning message is enabled. When
the write life span of the EEPROM is exceeded, a warning
message is generated. See additional sense error code C2 in
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. When the SSM bit is 1, the drive can send a synchronous
data transfer message, even when the initiator has not sent a
synchronous data transfer message.
When the disable unit attention (ATOFF) bit is 0, the drive
generates a unit attention condition during power up. When the
disable unit attention (ATOFF) bit is 1, the drive does not
generate a unit attention condition during power up.
Byte 3 The device type qualifier field can have a value from 00H through
7FH. This field can be read back by the host in Inquiry data,
byte 1. The Inquiry data is discussed in Appendix D.
Byte 4 The spinup delay field controls the drive when it is not in the
remote mode. When the value is 00H, the drive spins up without
delay. When the value is FFH, the drive delays spinup after a
duration, in seconds, equal to the drive’s SCSI bus ID number
times 5. When the value is 01H through FEH, the drive delays
spinup for the corresponding duration, in seconds.
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.1 Inquiry data
When the initiator issues an Inquiry command, and the EVDP bit in byte 1
of the Inquiry command descriptor block is 0, the drive returns the
following data. If the EVDP bit in byte 1 of the Inquiry command descriptor
block is 1, see Appendix D.2.
Bit
Byte
0
1
2
3
4
7
6
5
4
Peripheral qualifier
0
0
0
0
0
RMB
0
3
1
0
Peripheral device type
0
0
0
0
0
0
0
Device type qualifier
0
0
ISO version
ECMA version
0
0
0
AENC TrmIOP
0
2
0
0
Reserved
0
ANSI version
0
0
1
0
Response data format
0
0
1
0
Additional length (8FH)
5–6
Reserved (00H)
7
Rel Adr Wbus32 Wbus16 Sync Linked 0 CmdQue Sft Re
8–15
Vendor identification
16–31
Product identification
32–35
Product revision level
36–43
Drive serial number
44–95
Reserved
96–143
Copyright notice
144–147
Servo PROM part number
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.
Byte 2
The ISO version field contains zero, which means that we
do not claim compliance with ISO 9316.
The EMCA version field contains zero, which means that
we do not claim compliance with EMCA-111.
The ANSI version field contains two, which means that the
drive complies with ANSI SCSI-2 standard X3.131-199x.
Byte 3
The asynchronous event notification (AENC) bit is zero,
which means that the drive does not support asynchronous
event notification.
The terminate I/O process (TRMIOP) bit is zero, which
means that the drive does not support the terminate I/O
process message.
The response data format field contains two, which means
that the inquiry data is in standard SCSI-2 format.
Byte 4
The additional length field contains 143, which is the number of bytes contained in the inquiry data beyond byte 4.
This value represents a total inquiry data length of 148
bytes. If the allocation length in the CDB of the Inquiry
command is less than 148, the inquiry data is truncated, but
the additional length does not change.
Bytes 5–6
Reserved
Byte 7
The RelAdr bit is one, which means that the drive supports
the relative addressing mode.
The WBUS32 bit is zero, which means that the drive does
not support 32-bit data transfers.
The WBUS16 bit is zero, which means that the drive does
not support 16-bit data transfers.
The SYNC bit is one, which means that the drive supports
synchronous data transfer.
The Linked bit is one, which means that the drive supports
linked commands.
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.
Bytes 32–35
The product revision level field contains the last four
digits of the firmware release number in ASCII.
Bytes 36–43
The drive serial number field contains the serial number
of the drive in ASCII.
Bytes 44–95
Reserved. These bytes contain only zeros.
Bytes 96–143 The copyright notice field contains the following ASCII
string: “ Copyright (c) 1990 Seagate All rights reserved .”
Bytes 144–147 The servo PROM part number field contains the part
number of the PROM in ASCII.
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.
Bit
Byte
0
7
6
5
4
Peripheral qualifier
3
2
1
0
Peripheral device type
1
Page code
2
Reserved (00H)
3
Page length
Byte 0 The peripheral qualifier field contains zero, which means that the
drive is currently connected to the logical unit issuing the Inquiry
command.
The peripheral device type field contains zero, which means that
the drive is a direct access device.
Byte 1 The page code field contains the same value contained in the
page code field in byte 2 of the Inquiry command descriptor
block.
If the page code field contains any of the page codes shown in
the table below, the drive returns the corresponding page. The
available page codes are:
Page code
Description
00H
Supported vital product data pages
80H
Unit serial number page
81H
Implemented operating definitions page
C0H
Firmware numbers page (vendor-unique)
C1H
Data code page (vendor-unique)
C2H
Jumper settings page (vendor-unique)
Byte 2 Reserved
Byte 3 The page length field contains the length of the supported page
list.
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. If the drive does not return the serial
number, it returns spaces (20H).
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.
Bit
Byte
7
0
6
5
Peripheral qualifier
4
3
Page code (81H)
2
Reserved (00H)
4
5
6–8
1
0
Peripheral device type
1
3
2
Page length (05H)
SAVIMP
0
SAVIMP
0
SAVIMP
0
Current operating definition
Default operating definition
Supported operating definition
Byte 4
The current operating definition field contains the value of
the current operating definition.
Byte 5
The SAVIMP bit is always zero; therefore, the current
operating definition parameter cannot be saved. If the
SAVIMP bit is one, the current operating parameter can be
saved.
The default operating definition field contains the value of
the default operating definition. If no operating definition is
saved, the drive uses the default operating definition.
Bytes 6–8
If the SAVIMP bit is zero, the default definition parameter
cannot be saved. If the SAVIMP bit is one, the default
definition parameter can be saved.
The supported operating definition field contains the value
of the supported operating definition. If no supported operating definition is saved, the drive uses the default operating
definition.
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.
Bit
Byte
0
7
6
5
Peripheral qualifier
4
3
2
1
0
Peripheral device type
1
Page code (C0H)
2
Reserved (00H)
3
Page length (10H)
4–7
Download firmware number
8–11
Controller PROM number
12–15
Servo PROM number
16–19
EEPROM image number
Bytes 4–8
The download firmware number field contains the firmware number in ASCII.
Bytes 9–11
The controller PROM number field contains the controller
PROM number in ASCII.
Bytes 12–15 The servo PROM number field contains the servo PROM
in ASCII.
Bytes 16–19 The EEPROM image number field contains the EEPROM
image number in ASCII.
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.
Bytes 5–6
The week field contains the week, in ASCII, that the firmware was released.
D.2.5 Jumper Settings page (C2H)
The Jumper Settings page is shown below. The table summarizes the
function and the default value of each bit.
Bit
Byte
0
7
6
5
4
Peripheral qualifier
3
Page code (C2H)
2
Reserved (00H)
3
Page length (01H)
Reserved
1
0
Peripheral device type
1
4
2
MS
PE
SCSI ID
Byte 4 If the Motor Start (MS) bit is 1, the remote start enable jumper is
installed on pins 3 and 4 of the options jumper block. If the MS
bit is 0, the remote start enable jumper is not installed.
If the Parity Enable (PE) bit is 1, the parity enable jumper is
installed on pins 1 and 2 of the options jumper block. If the PE
bit is 0, the parity enable jumper is not installed.
SCSI ID is the SCSI ID of the drive.
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. Arbitration, selection (without ATN) and command
Description
Symbol
Typical
Max
Target select time
(without arbitration)
T00
<80 µsec
<250 msec
Target select time
(with arbitration)
T01
<90 µsec
<250 msec
Target select to command
T02
<150 µsec
—
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
<1.0 µsec
<250 µsec
Target select time
(with arbitration)
T01
<55 µsec
<250 µsec
Target select to message out
T03
<125 µsec
—
Message out byte transfer
T33
<0.1 µsec
0.15 µsec
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. Identify message out to command
Description
Identify message to command
Symbol
Typical
T04
<150 µsec
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. A 10-byte CDB requires
less than 110 µsec for 9 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
<0.1 µsec
0.15 µsec
Status byte transfer
T34
<0.1 µsec
0.15 µsec
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.
T11 *
Typical
Max
Command dependent
<100 µsec
—
Command dependent
* When measuring T11, no other device can be contending for the SCSI
bus.
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
0.15 µsec
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. Reselection, status, command complete and bus free
Description
Symbol
Typical
Max
Reselect identify message to
status
T15
<150 µsec
—
Status to command complete
message
T18
<150 µsec
—
Command complete message
to bus free
T19
<100 µsec
—
Message in byte transfer
T32
<0.1 µsec
0.15 µsec
Status byte transfer
T34
<0.1 µsec
0.15 µsec
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. Last command byte to data in
Description
Command to data in or
parameter in
Symbol
T06
Typical
Max
Command dependent
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. Last command byte to data out
Description
Symbol
Command to data out or
parameter out
T07
Command to data
(write to data buffer)
T08
Typical
Max
Command dependent
<500 µsec
1025 µsec
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. Reselect identify message to data in
Description
Reselect identify message to
data (media)
Symbol
T16
Typical
Max
Command dependent
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
1.5 µsec
Data in byte transfer (SYNC)
T28
<60 nsec
100 nsec
Next data in byte access
(SYNC)
T30
<600 nsec
1.2 µsec
The maximum SCSI asynchronous interface transfer rate is 5 Mbytes per
second. Therefore, the minimum time between two leading edges of a
request is 200 nsec.
The maximum SCSI synchronous interface transfer rate is 10.0 Mbytes
per second. Therefore, the minimum time between two leading edges of
a request is 100 nsec.
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
1.5 µsec
Data out byte transfer (SYNC)
T29
<60 nsec
100 nsec
Next data out byte access
(SYNC)
T31
<600 nsec
1.2 µsec
The maximum SCSI asynchronous interface transfer rate is 5 Mbytes per
second. Therefore, the minimum time between two leading edges of a
request is 200 nsec.
The maximum SCSI synchronous interface transfer rate is 10.0 Mbytes
per second. Therefore, the minimum time between two leading edges of
a request is 100 nsec.
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. Last data byte, save pointer message and disconnect message
Description
Symbol
Typical
Max
Disconnect message to bus
free
T10
<100 µsec
—
Data to save data pointer
message
T20
<175 µsec
—
Save data pointer message to
disconnect message
T21
<175 µsec
—
Message in byte transfer
T32
<0.1 µsec
0.15 µsec
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
<0.1 µsec
0.15 µsec
Status byte transfer
T34
<0.1 µsec
0.15 µsec
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
30.0 nsec
ACK– deassertion period
T8
30.0 nsec
ACK– period
T9
100 nsec
Last ACK– pulse high to phase
change
T10
125 nsec
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
30.0 nsec
—
ACK– low to data hold
T7
10 nsec
—
ACK– period
T8
100 nsec
—
REQ– low to ACK– low
T9
10 nsec
—
Last ACK– pulse high to phase
change
T10
125 nsec
—
Seagate Technology, Inc.
920 Disc Drive, Scotts Valley, California 95066, USA
Publication Number: 36243-001, Rev. A, Printed in USA