5.5
F
IRMWARE
F
EATURES
..................................................................................................................... 21
5.5.1
Read Caching ................................................................................................................. 21
5.5.2
Write Caching ................................................................................................................. 22
5.5.3
Defect Management ........................................................................................................ 22
5.5.4
Automatic Defect Allocation ........................................................................................... 22
5.5.5
Multi Parities Error Correction ..................................................................................... 22
CHAPTER 6
USB INTERFACE AND USB COMMANDS ............................................................ 23
6.1
I
NTRODUCTION
................................................................................................................................ 23
6.2
P
HYSICAL
I
NTERFACE
..................................................................................................................... 23
6.2.1
Mechanical Interface ...................................................................................................... 23
6.2.1.1
Mechanical Overview ................................................................................................................... 23
6.2.1.2
Connector ...................................................................................................................................... 24
6.2.1.2.1
USB Connector Termination Data................................................................................................................... 24
6.2.1.2.2
Series “A” and Series “B” Receptacles ........................................................................................................
25
6.2.1.2.3
Series “A” and Series “B” Plugs ...................................................................................................................
26
6.2.1.3
Cable.................................................................................................................................................
27
6.2.1.4
Cable Assembly.................................................................................................................................. 27
6.2.1.4.1
Standard Detachable Cable Assemblies ....................................................................................................
27
6.2.1.4.2
High-/full-speed Captive Cable Assemblies............................................................................................... 30
6.2.1.4.3
Low-speed Captive Cable Assemblies ........................................................................................................ 31
6.2.1.4.4
Prohibited Cable Assemblies ...................................................................................................................... 31
6.2.2
Electrical Interface .......................................................................................................... 32
6.2.2.1
Electrical Overview ............................................................................................................................ 32
6.2.2.2
Signaling ............................................................................................................................................ 33
6.2.2.3
High-speed (480Mb/s) Driver Characteristics ................................................................................... 34
6.2.2.4
High-speed (480Mb/s) Signaling Rise and Fall Times ...................................................................... 35
6.2.2.5
High-speed (480Mb/s) Receiver Characteristics ............................................................................... 35
6.2.2.6
High-speed (480Mb/s) Signaling Levels ........................................................................................... 36
6.2.3
Power Distribution ......................................................................................................... 37
6.2.3.1
Overview .............................................................................................................................................. 37
6.2.3.2
Bus-powered Hubs ............................................................................................................................... 37
6.2.3.3
Self-powered Hubs .............................................................................................................................. 38
6.3
P
ROTOCOL
L
AYER
............................................................................................................................ 39
6.3.1
Protocol Layer Overview................................................................................................ 39
6.3.2
Common USB Packet Fields ........................................................................................... 40
6.3.2.1
SYNC Fields...................................................................................................................................... 40
6.3.2.2
Packet Identifier Fields...................................................................................................................... 40
6.3.2.3
Address Fields .................................................................................................................................. 41
6.3.2.4
Endpoint Fields.................................................................................................................................. 42
6.3.2.5
Frame Number Fields ....................................................................................................................... 42
6.3.2.6
Data Fields ........................................................................................................................................ 42
6.3.2.7
Cyclic Redundancy Checks .............................................................................................................. 42
6.3.3
Packet Format ................................................................................................................. 43
6.3.3.1
Token Packet..................................................................................................................................... 43
6.3.3.2
Data Packet ....................................................................................................................................... 43
6.3.3.3
Handshake Packet ............................................................................................................................. 43
6.3.3.4
Start-of-Frame Packets...................................................................................................................... 44
6.3.4
Pipes ................................................................................................................................ 44
6.3.5
Transfer/Endpoint Types ................................................................................................. 45
6.3.5.1
Control Transaction........................................................................................................................... 46
6.3.5.2
Bulk Transaction................................................................................................................................ 48
6.3.6
USB Device Generic Framework .................................................................................... 50
6.3.6.1
USB Device State ............................................................................................................................. 50
6.3.6.1.1
Attached .................................................................................................................................................. 51
6.3.6.1.2
Powered ................................................................................................................................................... 51
6.3.6.1.3
Default ..................................................................................................................................................... 52
6.3.6.1.4
Address ..................................................................................................................................................... 52
6.3.6.1.5
Configured ................................................................................................................................................ 52
6.3.6.1.6
Suspended ................................................................................................................................................ 52
6.3.6.1.7
Bus Enumeration ..................................................................................................................................... 52
6.3.6.2
Generic USB Device Operation...................................................................................................... 53
6.3.6.2.1
Dynamic Attachment and Removal ......................................................................................................... 53
6.3.6.2.2
Address Assignment ................................................................................................................................. 53
6.3.6.2.3
Configuration............................................................................................................................................ 54
6.3.6.2.4
Data Transfer ........................................................................................................................................... 54
6.3.6.2.5
Power Management .................................................................................................................................. 54
6.3.6.2.6
Request Processing ................................................................................................................................... 54
