Seagate M8U-Internal Product Manual REV 4.0
5.3 SERVO SYSTEM ................................................................................................................................28
5.4 R
EAD AND WRITE OPERATIONS ......................................................................................................28
5.4.1 The Read Channel...........................................................................................................28
5.4.2 The Write Channel ..........................................................................................................29
5.5 F
IRMWARE FEATURES .....................................................................................................................29
5.5.1 Read Caching .................................................................................................................29
5.5.2 Write Caching .................................................................................................................30
5.5.3 Defect Management ........................................................................................................31
5.5.4 Automatic Defect Allocation ...........................................................................................31
5.5.5 Multi-burst ECC Correction ...........................................................................................31
CHAPTER 6 USB INTERFACE AND USB COMMANDS ............................................................32
6.1 INTRODUCTION ................................................................................................................................32
6.2 P
HYSICAL INTERFACE .....................................................................................................................32
6.2.1 Mechanical Interface ......................................................................................................33
6.2.1.1 Mechanical Overview ................................................................................................................... 33
6.2.1.2 Connector ...................................................................................................................................... 33
6.2.1.2.1 USB Connector Termination Data..................................................................................34
6.2.1.2.2 Series “A” and Series “B” Receptacles .........................................................................35
6.2.1.2.3 Series “A” and Series “B” Plugs ...................................................................................36
6.2.1.3 Cable...............................................................................................................................37
6.2.1.4 Cable Assembly...............................................................................................................37
6.2.1.4.1 Standard Detachable Cable Assemblies .........................................................................37
6.2.1.4.2 High-/full-speed Captive Cable Assemblies....................................................................38
6.2.1.4.3 Low-speed Captive Cable Assemblies ............................................................................39
6.2.1.4.4 Prohibited Cable Assemblies ..........................................................................................39
6.2.2 Electrical Interface .........................................................................................................40
6.2.2.1 Electrical Overview ........................................................................................................40
6.2.2.2 Signaling .........................................................................................................................41
6.2.2.3 High-speed (480Mb/s) Driver Characteristics ...............................................................42
6.2.2.4 High-speed (480Mb/s) Signaling Rise and Fall Times ...................................................43
6.2.2.5 High-speed (480Mb/s) Receiver Characteristics ............................................................43
6.2.2.6 High-speed (480Mb/s) Signaling Levels .........................................................................44
6.2.3 Power Distribution .........................................................................................................45
6.2.3.1 Overview .........................................................................................................................45
6.2.3.2 Bus-powered Hubs ..........................................................................................................45
6.2.3.3 Self-powered Hubs ..........................................................................................................46
6.3 P
ROTOCOL LAYER ...........................................................................................................................47
6.3.1 Protocol Layer Overview................................................................................................47
6.3.2 Common USB Packet Fields ...........................................................................................48
6.3.2.1 SYNC Fields....................................................................................................................48
6.3.2.2 Packet Identifier Fields...................................................................................................48
6.3.2.3 Address Fields ................................................................................................................49
6.3.2.4 Endpoint Fields...............................................................................................................50
6.3.2.5 Frame Number Fields .....................................................................................................50
6.3.2.6 Data Fields .....................................................................................................................50
6.3.2.7 Cyclic Redundancy Checks .............................................................................................50
6.3.3 Packet Format ................................................................................................................51
6.3.3.1 Token Packet...................................................................................................................51
6.3.3.2 Data Packet ....................................................................................................................52
6.3.3.3 Handshake Packet ..........................................................................................................52
6.3.3.4 Start-of-Frame Packets...................................................................................................53
6.3.4 Pipes ...............................................................................................................................53
6.3.5 Transfer/Endpoint Types ................................................................................................54
6.3.5.1 Control Transaction........................................................................................................55
6.3.5.2 Bulk Transaction.............................................................................................................57
6.3.6 USB Device Generic Framework ...................................................................................59
6.3.6.1 USB Device State ............................................................................................................59
6.3.6.1.1 Attatched .........................................................................................................................60