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Fujitsu MHM2150AT Manual/User Guide - Page 218

In the case that the contents of buffer is as follows at receiving a read

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6.5 Read-Ahead Cache b. Sequential hit When the previously executed read command is the sequential command and the last sector address of the previous read command is sequential to the lead sector address of the received read command, the disk drive transfers the hit data in the buffer to the host system. The disk drive performs the read-ahead operation of the new continuous data to the empty area that becomes vacant by data transfer at the same time as the disk drive starts transferring data to the host system. 1) In the case that the contents of buffer is as follows at receiving a read command; HAP (Continued from the previous read request data) Read-ahead data Hit data DAP Last LBA Start LBA 2) The disk drive starts the read-ahead operation to the empty area that becomes vacant by data transfer at the same time as the disk drive starts transferring hit data. HAP Read-ahead data New read-ahead data Hit data DAP 3) After completion of data transfer of hit data, the disk drive performs the readahead operation for the data area of which the disk drive transferred hit data. HAP Read-ahead data DAP C141-E104-03EN 6-19

Section	Page
Cover	1
Revision History	4
Preface	6
Important Alert Items	10
Manual Organization	12
Contents	14
Illustrations	19
CHAPTER 1 Device Overview	22
1.1 Features	23
1.1.1 Functions and performance	23
1.1.2 Adaptability	23
1.1.3 Interface	24
1.2 Device Specifications	25
1.2.1 Specifications summary	25
1.2.2 Model and product number	26
1.3 Power Requirements	26
1.4 Environmental Specifications	28
1.5 Acoustic Noise	29
1.6 Shock and Vibration	29
1.7 Reliability	30
1.8 Error Rate	31
1.9 Media Defects	31
CHAPTER 2 Device Configuration	32
2.1 Device Configuration	33
2.2 System Configuration	35
2.2.1 ATA interface	35
2.2.2 1 drive connection	35
2.2.3 2 drives connection	35
CHAPTER 3 Installation Conditions	38
3.1 Dimensions	39
3.2 Mounting	41
3.3 Cable Connections	47
3.3.1 Device connector	47
3.3.2 Cable connector specifications	48
3.3.3 Device connection	48
3.3.4 Power supply connector (CN1)	49
3.4 Jumper Settings	49
3.4.1 Location of setting jumpers	49
3.4.2 Factory default setting	50
3.4.3 Master drive-slave drive setting	50
3.4.4 CSEL setting	51
CHAPTER 4 Theory of Device Operation	54
4.1 Outline	55
4.2 Subassemblies	55
4.2.1 Disk	55
4.2.2 Head	55
4.2.3 Spindle	56
4.2.4 Actuator	56
4.2.5 Air filter	56
4.3 Circuit Configuration	57
4.4 Power-on Sequence	60
4.5 Self-calibration	61
4.5.1 Self-calibration contents	61
4.5.2 Execution timing of self-calibration	62
4.5.3 Command processing during self-calibration	63
4.6 Read/write Circuit	63
4.6.1 Read/write preamplifier (HDIC)	63
4.6.2 Write circuit	64
4.6.3 Read circuit	66
4.6.4 Digital PLL circuit	67
4.7 Servo Control	68
4.7.1 Servo control circuit	68
4.7.2 Data-surface servo format	71
4.7.3 Servo frame format	73
4.7.4 Actuator motor control	74
4.7.5 Spindle motor control	75
CHAPTER 5 Interface	78
5.1 Physical Interface	79
5.1.1 Interface signals	79
5.1.2 Signal assignment on the connector	80
5.2 Logical Interface	83
5.2.1 I/O registers	84
5.2.2 Command block registers	85
5.2.3 Control block registers	90
5.3 Host Commands	90
5.3.1 Command code and parameters	91
5.3.2 Command descriptions	93
5.3.3 Error posting	160
5.4 Command Protocol	162
5.4.1 Data transferring commands from device to host	162
5.4.2 Data transferring commands from host to device	164
5.4.3 Commands without data transfer	166
5.4.4 Other commands	167
5.4.5 DMA data transfer commands	167
5.5 Ultra DMA Feature Set	169
5.5.1 Overview	169
5.5.2 Phases of operation	170
5.5.2.1 Ultra DMA burst initiation phase	170
5.5.2.2 Data transfer phase	171
5.5.2.3 Ultra DMA burst termination phase	171
5.5.3 Ultra DMA data in commands	172
5.5.3.1 Initiating an Ultra DMA data in burst	172
5.5.3.2 The data in transfer	173
5.5.3.3 Pausing an Ultra DMA data in burst	173
5.5.3.4 Terminating an Ultra DMA data in burst	174
5.5.4 Ultra DMA data out commands	177
5.5.4.1 Initiating an Ultra DMA data out burst	177
5.5.4.2 The data out transfer	177
5.5.4.3 Pausing an Ultra DMA data out burst	178
5.5.4.4 Terminating an Ultra DMA data out burst	179
5.5.5 Ultra DMA CRC rules	181
5.5.6 Series termination required for Ultra DMA	183
5.6 Timing	184
5.6.1 PIO data transfer	184
5.6.2 Multiword DMA data transfer	186
5.6.3 Transfer of Ultra DMA data	187
5.6.3.1 Starting of Ultra DMA data In Burst	187
5.6.3.2 Ultra DMA data burst timing requirements	188
5.6.3.3 Sustained Ultra DMA data in burst	190
5.6.3.4 Host pausing an Ultra DMA data in burst	191
5.6.3.5 Device terminating an Ultra DMA data in burst	192
5.6.3.6 Host terminating an Ultra DMA data in burst	193
5.6.3.7 Initiating an Ultra DMA data out burst	194
5.6.3.8 Sustained Ultra DMA data out burst	195
5.6.3.9 Device pausing an Ultra DMA data out burst	196
5.6.3.10 Host terminating an Ultra DMA data out burst	197
5.6.3.11 Device terminating an Ultra DMA data in burst	198
5.6.4 Power-on and reset	199
CHAPTER 6 Operations	200
6.1 Device Response to the Reset	201
6.1.1 Response to power-on	201
6.1.2 Response to hardware reset	203
6.1.3 Response to software reset	204
6.1.4 Response to diagnostic command	205
6.2 Address Translation	206
6.2.1 Default parameters	206
6.2.2 Logical address	207
6.3 Power Save	208
6.3.1 Power save mode	208
6.3.2 Power commands	210
6.4 Defect Management	210
6.4.1 Spare area	211
6.4.2 Alternating defective sectors	211
6.5 Read-Ahead Cache	213
6.5.1 Data buffer configuration	213
6.5.2 Caching operation	213
6.5.3 Usage of read segment	215
6.5.3.1 Mis-hit (no hit)	215
6.5.3.2 Sequential read	216
6.5.3.3 Full hit (hit all)	219
6.5.3.4 Partially hit	220
6.6 Write Cache	221
Glossary	224
Acronyms and Abbreviations	228