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Seek overlap

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10.9 Seek overlap HDS7280x0PLATy0 provides an accurate method for measuring seek time. The seek command is usually used to measure the device seek time by accumulating the execution time for a number of seek commands. With typical implementation of seek command this measurement must include the device and host command overhead. To eliminate this overhead the drive overlaps the seek command as described below. The first seek command is completed before the actual seek operation is ended. Then the device can receive the next seek command from the host; however, the actual seek operation for the next seek command starts immediately after the actual seek operation for the first seek command is completed. In other words, the execution of two seek commands overlaps excluding the time required for the actual seek operation. With this overlap the total elapsed time for a number of seek commands results in the total accumulated time for actual seek operation plus one pre- and post-overhead. When the number of seeks is large, only one overhead may be ignored. Table 69: Seek overlap ( 1) Wi t h over l ap Host pr ocess Devi ce pr ocess Seek oper at i on Over head A B Tot al t i me = ( n- 1) * ( Seek oper at i on) + A + B ( 2) Wi t hout over l ap Host pr ocess Devi ce pr ocess Seek oper at i on Over head A B+A B Tot al t i me = n * ( Seek oper at i on + A + B) Deskstar 7K80 Hard Disk Drive Specification 98

Section	Page
1.0 General	15
1.1 Introduction	15
1.2 References	15
1.3 Abbreviations	15
1.4 Caution	17
2.0 General features of the drive	19
3.0 Fixed-disk subsystem description	23
3.1 Control electronics	23
3.2 Head disk assembly	23
3.3 Actuator	23
4.0 Drive characteristics	25
4.1 Default logical drive parameters	25
4.2 Data sheet	26
4.3 World Wide Name Assignment	26
4.4 Drive organization	26
4.4.1 Drive format	26
4.4.2 Cylinder allocation	27
4.5 Performance characteristics	28
4.5.1 Command overhead	28
4.5.2 Mechanical positioning	28
4.5.3 Drive ready time	30
4.5.4 Data transfer speed	31
4.5.5 Throughput	32
4.5.6 Operating modes	33
5.0 Defect flagging strategy	35
6.0 Electrical interface specification	37
6.1 Connector location	37
6.1.1 DC power connector	37
6.1.2 AT signal connector	37
6.2 Signal definitions	38
6.3 Signal descriptions	39
6.4 Interface logic signal levels	42
6.5 Reset timings	42
6.6 PIO timings	43
6.6.1 Write DRQ interval time	43
6.6.2 Read DRQ interval time	43
6.7 Multi-word DMA timings	45
6.8 Ultra DMA timings	46
6.8.1 Initiating Read DMA	46
6.8.2 Host Pausing Read DMA	47
6.8.3 Host Terminating Read DMA	48
6.8.4 Device Terminating Read DMA	49
6.8.5 Initiating Write DMA	50
6.8.6 Device Pausing Write DMA	51
6.8.7 Device Terminating Write DMA	52
6.8.8 Host Terminating Write DMA	53
6.9 Addressing of registers	54
6.9.1 Cabling	54
7.0 Specification	57
7.1 Jumper settings	57
7.1.1 Jumper pin location	57
7.1.2 Jumper pin identification	57
7.1.3 Jumper pin assignment	58
7.1.4 Jumper positions	58
7.2 Environment	62
7.2.1 Temperature and humidity	62
7.2.2 Corrosion test	63
7.3 DC power requirements	63
7.3.1 Input voltage	63
7.3.2 Power supply current (typical)	64
7.3.3 Power supply generated ripple at drive power connector	64
7.4 Reliability	65
7.4.1 Data integrity	65
7.4.2 Cable noise interference	65
7.4.3 Start/stop cycles	65
7.4.4 Preventive maintenance	65
7.4.5 Data reliability	65
7.4.6 Required power-off sequence	65
7.5 Mechanical specifications	66
7.5.1 Physical dimensions and weight	66
7.5.2 Mounting hole locations	67
7.5.3 Connector locations	67
7.5.4 Drive mounting	68
7.5.5 Heads unload and actuator lock	68
7.6 Vibration and shock	69
7.6.1 Operating vibration	69
7.6.2 Nonoperating vibration	69
7.6.3 Operating shock	70
7.6.4 Nonoperating shock	70
7.6.5 Nonoperating rotational shock	71
7.7 Acoustics	72
7.8 Identification labels	72
7.9 Safety	73
7.9.1 UL and CSA approval	73
7.9.2 German safety mark	73
7.9.3 Flammability	73
7.9.4 Safe handling	73
7.9.5 Environment	73
7.9.6 Secondary circuit protection	73
7.10 Electromagnetic compatibility	74
7.10.1 C-TICK mark	74
7.10.2 BSMI mark	74
7.11 Packaging	74
8.0 General	75
8.1 Introduction	75
8.2 Terminology	75
8.3 Deviations from standard	75
9.0 Registers	77
9.1 Register set	77
9.2 Alternate Status Register	78
9.3 Command Register	78
9.4 Cylinder High Register	78
9.5 Cylinder Low Register	78
9.6 Data Register	79
9.7 Device Control Register	79
9.8 Drive Address Register	80
9.9 Device/Head Register	80
9.10 Error Register	81
9.11 Features Register	81
9.12 Sector Count Register	81
9.13 Sector Number Register	82
9.14 Status Register	82
10.0 General operation	85
10.1 Reset response	85
10.2 Register initialization	86
10.3 Diagnostic and Reset considerations	87
10.4 Sector Addressing Mode	88
10.4.1 Logical CHS addressing mode	88
10.4.2 LBA addressing mode	88
10.5 Power management features	89
10.5.1 Power mode	89
10.5.2 Power management commands	89
10.5.3 Standby timer	89
10.5.4 Interface capability for power modes	90
10.6 S.M.A.R.T. Function	91
10.6.1 Attributes	91
10.6.2 Attribute values	91
10.6.3 Attribute thresholds	91
10.6.4 Threshold exceeded condition	91
10.6.5 S.M.A.R.T. commands	91
10.6.6 Off-line read scanning	91
10.6.7 Error log	92
10.6.8 Self-test	92
10.7 Security Mode Feature Set	93
10.7.1 Security mode	93
10.7.2 Security level	93
10.7.3 Passwords	94
10.7.4 Operation example	94
10.7.5 Command table	98
10.8 Host Protected Area Feature	100
10.8.1 Example for operation (In LBA Mode)	100
10.8.2 Security extensions	101
10.9 Seek overlap	102
10.10 Write cache function	103
10.11 Reassign function	104
10.11.1 Auto Reassign function	104
10.12 Power-Up in Standby feature set	105
10.13 Advanced Power Management feature set (APM)	106
10.14 Automatic Acoustic Management feature set (AAM)	107
10.15 Address Offset Feature	108
10.15.1 Enable/Disable Address Offset Mode	108
10.15.2 Identify Device Data	109
10.15.3 Exceptions in Address Offset Mode	109
10.16 48-bit Address Feature Set	110
10.17 Streaming feature Set	110
10.17.1 Streaming commands	111
10.17.2 Urgent bit	111
10.17.3 Flush to Disk bit	111
10.17.4 Not Sequential bit	112
10.17.5 Read Continuous bit	112
10.17.6 Write Continuous bit	112
10.17.7 Handle Streaming Error bit	112
10.17.8 Streaming Logs	112
11.0 Command protocol	113
11.1 PIO Data In commands	113
11.2 PIO Data Out Commands	114
11.3 Non-data commands	116
11.4 DMA commands	117
12.0 Command descriptions	119
12.1 Check Power Mode (E5h/98h)	124
12.2 Configure Stream (51h)	125
12.3 Device Configuration Overlay (B1h)	127
12.3.1 DEVICE CONFIGURATION RESTORE (Subcommand C0h)	127
12.3.2 DEVICE CONFIGURATION FREEZE LOCK (subcommand C1h)	127
12.3.3 DEVICE CONFIGURATION IDENTIFY (subcommand C2h)	128
12.3.4 DEVICE CONFIGURATION SET (subcommand C3h)	128
12.4 Download Microcode (92h)	131
12.5 Execute Device Diagnostic (90h)	133
12.6 Flush Cache (E7h)	134
12.7 Flush Cache Ext (EAh)	135
12.8 Format Track (50h)	136
12.9 Format Unit (F7h)	138
12.10 Identify Device (ECh)	139
12.11 Idle (E3h/97h)	147
12.12 Idle Immediate (E1h/95h)	148
12.13 Initialize Device Parameters (91h)	149
12.14 Read Buffer (E4h)	150
12.15 Read DMA (C8h/C9h)	151
12.16 Read DMA Ext (25h)	153
12.17 Read Log Ext (2Fh)	155
12.17.1 General Purpose Log Directory	157
12.17.2 Extended Comprehensive SMART Error Log	158
12.17.3 Extended Self-test log sector	160
12.17.4 Read Stream Error Log	161
12.17.5 Write Stream Error Log	162
12.17.6 Streaming Performance Log	163
12.18 Read Long (22h/23h)	165
12.19 Read Multiple (C4h)	167
12.20 Read Multiple Ext (29h)	168
12.21 Read Native Max ADDRESS (F8h)	170
12.22 Read Native Max Address Ext (27h)	171
12.23 Read Sectors (20h/21h)	172
12.24 Read Sector(s) Ext (24h)	174
12.25 Read Stream DMA (2Ah)	176
12.26 Read Stream PIO (2Bh)	180
12.27 Read Verify Sectors (40h/41h)	183
12.28 Read Verify Sectors Ext (42h)	185
12.29 Recalibrate (1xh)	187
12.30 Security Disable Password (F6h)	188
12.31 Security Erase Prepare	189
12.32 Security Erase Unit (F4h)	190
12.33 Security Freeze Lock (F5h)	192
12.34 Security Set Password (F1h)	193
12.35 Security Unlock (F2h)	195
12.36 Seek (7xh)	197
12.37 Set Features (EFh)	198
12.37.1 Set Transfer mode	199
12.37.2 Write Cache	199
12.37.3 Advanced Power Management	199
12.37.4 Automatic Acoustic Management	201
12.38 Set Max ADDRESS (F9h)	202
12.38.1 Set Max Set Password (Feature=01h)	204
12.38.2 Set Max Lock (Feature=02h)	205
12.38.3 Set Max Unlock (Feature = 03h)	206
12.38.4 Set Max Freeze Lock (Feature = 04h)	207
12.39 Set Max Address Ext (37h)	208
12.40 Set Multiple (C6h)	210
12.41 Sleep (E6h/99h)	211
12.42 S.M.A.R.T. Function Set (B0h)	212
12.42.1 S.M.A.R.T. Function Subcommands	213
12.42.2 Device Attribute Data Structure	217
12.42.3 Device Attribute Thresholds data structure	220
12.42.4 S.M.A.R.T. Log Directory	222
12.42.5 S.M.A.R.T. summary error log sector	222
12.42.6 Self-test log data structure	224
12.42.7 Error reporting	225
12.43 Standby (E2h/96h)	226
12.44 Standby Immediate (E0h/94h)	228
12.45 Write Buffer (E8h)	229
12.46 Write DMA (CAh/CBh)	230
12.47 Write DMA Ext (35h)	232
12.48 Write Log Ext (3Fh)	234
12.49 Write Long (32h/33h)	235
12.50 Write Multiple (C5h)	237
12.51 Write Multiple Ext (39h)	239
12.52 Write Sectors (30h/31h)	241
12.53 Write Sectors Ext	243
12.54 Write Stream DMA (3Ah)	245
12.55 Write Stream PIO (3Bh)	247

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Deskstar 7K80 Hard Disk Drive Specification

10.9

Seek overlap

HDS7280x0PLATy0 provides an accurate method for measuring seek time.

The seek command is usually used to

measure the device seek time by accumulating the execution time for a number of seek commands. With typical

implementation of seek command this measurement must include the device and host command overhead. To

eliminate this overhead the drive overlaps the seek command as described below.

The first seek command is completed before the actual seek operation is ended. Then the device can receive the next

seek command from the host; however, the actual seek operation for the next seek command starts immediately after

the actual seek operation for the first seek command is completed. In other words, the execution of two seek

commands overlaps excluding the time required for the actual seek operation.

With this overlap the total elapsed time for a number of seek commands results in the total accumulated time for

actual seek operation plus one pre- and post-overhead. When the number of seeks is large, only one overhead may

be ignored.

Table 69: Seek overlap

(1) W

i t h over l ap

(2) W

i t hout over l ap

Host pr ocess

Devi ce pr ocess

Seek oper at i on

Over head

B+A

Tot al t i me = ( n- 1) * ( Seek oper at i on) + A + B

Tot al t i me = n * ( Seek oper at i on + A + B)