- •TABLE OF CONTENTS
- •1.1 Motivation
- •1.2 Design Goals
- •1.3 Objective of the Specification
- •1.4 Scope of the Document
- •1.5 USB Product Compliance
- •1.6 Document Organization
- •2.1 Terms
- •2.2 Conventions:
- •2.3 References
- •3.1 USB System Description
- •3.1.1 Topology
- •3.1.1.1 USB Host
- •3.1.1.2 Wireless USB Devices
- •3.2 Physical Interface
- •3.3 Power Management
- •3.4 Bus Protocol
- •3.5 Robustness
- •3.5.1 Error Handling
- •3.6 Security
- •3.7 System Configuration
- •3.7.1 Attachment of Wireless USB Devices
- •3.7.2 Removal of Wireless USB Devices
- •3.7.3 Bus Enumeration
- •3.8 Data Flow Types
- •3.9 Wireless USB Devices
- •3.9.1 Device Characterizations
- •3.9.2 Devices and MAC Layer
- •3.10 Wireless USB Host: Hardware and Software
- •4.1 Implementer Viewpoints
- •4.2 Communications Topology
- •4.2.1 Physical Topology
- •4.3 Wireless USB Communication Flows
- •4.3.1 Wireless USB Channel Time
- •4.3.2 MMC Transmission Accuracy
- •4.3.3 USB Time across Device Wire Adapters
- •4.3.5 Device Endpoints
- •4.3.6 Wireless USB Information Exchange Methods
- •4.3.7 Device Perspective
- •4.3.7.1 Self Beaconing Devices
- •4.3.7.2 Directed Beaconing Devices
- •4.3.7.3 Non Beaconing Devices
- •4.3.7.4 Selecting A Wireless USB Host
- •4.3.8 Host Perspective
- •4.3.8.1 MAC Layer Compliant Device
- •4.3.8.2 Wireless USB Host
- •4.3.8.3 Host System Management
- •4.3.8.5 Other Host Considerations
- •4.4 Data Transfers
- •4.4.1 Burst Mode Data Phase
- •4.5 Bulk Transfers
- •4.5.1 Bulk Transfer Packet Size and Signaling Rate Constraints
- •4.5.2 Bulk Transfer Channel Access Constraints
- •4.5.3 Bulk Transfer Data Sequences
- •4.6 Interrupt Transfers
- •4.6.1 Low Power Interrupt IN
- •4.6.2 Interrupt Transfer Packet Size and Signaling Rate Constraints
- •4.6.3 Interrupt Transfer Channel Access Constraints
- •4.6.4 Interrupt Transfer Data Sequences
- •4.7 Isochronous Transfers
- •4.7.1 Isochronous Transfer Packet Size and Signaling Rate Constraints
- •4.7.2 Isochronous Transfer Channel Access Constraints
- •4.7.3 Isochronous Transfer Data Sequences
- •4.7.4 Isochronous Endpoint Host System Admission Decisions
- •4.7.5 Isochronous Data Discards and Use of Isochronous Packet Discard IE
- •4.8 Control Transfers
- •4.8.1 Control Transfer Packet Size and Signaling Rate Constraints
- •4.8.2 Control Transfer Channel Access Constraints
- •4.8.3 Control Transfer Data Sequences
- •4.8.4 Data Loopback Commands
- •4.9 Device Notifications
- •4.10 Media Reliability Considerations
- •4.10.1 Transmit Power Control
- •4.10.2 Adjustments to Data Phase Packet Payload Sizes
- •4.10.3 Adjustments to Transmit Bit Rate
- •4.10.4 Changing PHY Channel
- •4.10.5 Host Schedule Control
- •4.10.6 Dynamic Bandwidth Interface Control
- •4.11 Special Considerations for Isochronous Transfers
- •4.11.1 Summary Of Key Features Of USB Wired Isochrony
- •4.11.1.1 Wireless Service Intervals
- •4.11.2 UWB Media Characteristics
- •4.11.2.1 Superframe Layout
- •4.11.2.2 Worst Case Superframe Layout – Service Interval Bounds.
- •4.11.2.3 Wireless Packet Error Rates
- •4.11.3 Wireless USB Isochronous Transfer Level Protocol
- •4.11.4 Wireless USB Isochronous IN Example
- •4.11.5 Wireless USB Isochronous OUT Example
- •4.11.6 Choosing an Isochronous IN or Isochronous OUT Endpoint Buffer Size
- •4.11.7 Isochronous OUT endpoint receiver implementation options
- •4.11.7.1 Presentation Time aware implementation
- •4.11.7.2 Presentation time aware implementation with “false” acknowledgement
- •4.11.7.3 Presentation time unaware implementations
- •4.11.8 Synchronization
- •4.11.8.1 Synchronizing a Stream Start Time
- •4.11.9 Error Handling Details
- •4.11.9.1 Reporting Data Discarded At the Transmitter
- •4.11.9.2 Discarding Data during A Burst
- •4.11.9.3 Application Handling of Discards
- •4.12 Device Reset
- •4.13 Connection Process
- •4.13.1 Reconnection Process
- •4.14 Disconnect
- •4.15 Security Mechanisms
- •4.15.1 Connection Lifetime
- •4.15.2 Host Security Considerations
- •4.15.2.1 CHID Selection
- •4.15.2.2 CDID Selection
- •4.16 Wireless USB Power Management
- •4.16.1 Device Power Management
- •4.16.1.1 Device Sleep
- •4.16.1.2 Device Wakeup
- •4.16.2 Host Power Management
- •4.16.2.1 Channel Stop
- •4.16.2.2 Remote Wakeup
- •4.16.2.3 Channel Start
- •4.17 Dual Role Devices (DRD)
- •4.17.2 Pairing P2P-DRD to establish reverse link
- •5.1 Packet Formats
- •5.2 Wireless USB Transaction Groups
- •5.2.1 Wireless USB Channel Time Allocation Information Elements
- •5.3 Transaction Group Timing Constraints
- •5.3.1 Streaming-Mode Inter-packet Constraints for the PHY
- •5.3.2 Protocol Synchronization
- •5.4 Data Burst Synchronization and Retry
- •5.5 Wireless USB Transactions
- •5.5.1 Isochronous Transactions
- •5.5.2 Control Transfers
- •5.5.3 Device Notifications
- •5.5.4 Flow Control
- •6.1 Introduction
- •6.1.1 Goal of USB Security
- •6.1.2 Security and USB
- •6.2 Overview
- •6.2.1 Base of Trust
- •6.2.2 Preserve the Nature of the USB Device Model
- •6.2.3 Implementation of Security Extensions
- •6.2.4 Encryption Methods
- •6.2.5 Message Format
- •6.2.6 Encryption Keys
- •6.2.6.1 Master Keys
- •6.2.6.2 Session Keys
- •6.2.7 Correct key determination
- •6.2.8 Replay Prevention
- •6.2.9 Secure Packet Reception
- •6.2.10 General Connection Model
- •6.2.10.1 Connection Context
- •6.2.10.2 Connection Lifetime
- •6.2.10.3 New Connection
- •6.2.10.4 Connection
- •6.2.10.5 Reconnection
- •6.2.10.6 Revocation
- •6.2.10.8 Diagnostic Support
- •6.2.10.9 Mutual Authentication
- •6.2.11 Key Management
- •6.2.11.1 PTK Management
- •6.2.11.2 GTK Management
- •6.3 Association and Authentication
- •6.3.1 Connection and Reconnection Requests
- •6.3.2 Authentication
- •6.3.2.1 Authentication Related Device Capabilities
- •6.3.2.2 Ceremonies
- •6.4.1 CCM nonce Construction
- •6.4.2 l(m) and l(a) Calculation
- •6.4.3 Counter-mode Bx Blocks
- •6.4.4 Encryption Ax Blocks
- •6.5.1 Key Derivation
- •6.5.2 Out-of-band MIC Generation
- •6.5.3 Example Random Number Generation
- •7.1 Wireless USB Device States
- •7.1.1 UnConnected
- •7.1.2 UnAuthenticated
- •7.1.3 Authenticated
- •7.1.4 Reconnecting
- •7.2 Generic Wireless USB Device Operations
- •7.3 Standard Wireless USB Device Requests
- •7.3.1 Wireless USB Extensions to Standard Requests
- •7.3.1.1 Clear Feature
- •7.3.1.2 Get Status
- •7.3.1.3 Set Address
- •7.3.1.4 Set Feature
- •7.3.1.5 Set Interface DS
- •7.3.1.6 Set WUSB Data
- •7.3.1.7 Data Loopback Write
- •7.3.1.8 DATA Loopback Read
- •7.3.2 Security-related Requests
- •7.3.2.1 Get Security Descriptor
- •7.3.2.2 Set Encryption
- •7.3.2.3 Get Encryption
- •7.3.2.4 Key Management
- •7.3.2.6 Set Security Data
- •7.3.2.7 Get Security Data
- •7.4 Standard Wireless USB Descriptors
- •7.4.1 Device Level Descriptors
- •7.4.1.1 Wireless USB Device Capabilities – UWB
- •7.4.2 Configuration
- •7.4.3 Endpoint
- •7.4.4 Wireless USB Endpoint Companion
- •7.4.5 Security-Related Descriptors
- •7.4.5.1 Security Descriptor
- •7.4.5.2 Key Descriptor
- •7.5 Wireless USB Channel Information Elements
- •7.5.1 Wireless USB Connect Acknowledge IE
- •7.5.2 Wireless USB Host Information IE
- •7.5.3 Wireless USB Channel Change Announcement IE
- •7.5.4 Wireless USB Device Disconnect IE
- •7.5.5 Wireless USB Host Disconnect IE
- •7.5.6 Wireless USB Release Channel IE
- •7.5.7 Wireless USB Work IE
- •7.5.8 Wireless USB Channel Stop IE
- •7.5.9 Wireless USB Device Keepalive IE
- •7.5.10 Wireless USB Isochronous Packet Discard IE
- •7.5.11 Wireless USB Reset Device IE
- •7.5.12 Wireless USB Transmit Packet Adjustment IE
- •7.6 Device Notifications
- •7.6.1 Device Connect (DN_Connect)
- •7.6.1.1 Connect Request
- •7.6.1.2 Reconnect Request
- •7.6.2 Device Disconnect (DN_Disconnect)
- •7.6.3 Device Endpoints Ready (DN_EPRdy)
- •7.6.4 Device MAS Availability Changed (DN_MASAvailChanged)
- •7.6.5 Device Sleep (DN_Sleep)
- •7.6.6 Remote Wakeup (DN_RemoteWakeup)
- •7.6.7 Device Alive (DN_Alive)
- •8.1 Operational Model
- •8.1.1 Functional Characteristics
- •8.1.2 Data Transfer Interface
- •8.1.3 Remote Pipe
- •8.1.4 Wire Adapter Functional Blocks
- •8.1.5 Downstream Port(s)
- •8.1.6 Upstream Port
- •8.1.7 Downstream Host Controller
- •8.1.8 Upstream Endpoint Controller
- •8.1.9 Remote Pipe Controller
- •8.1.9.1 RPipe Descriptor
- •8.1.9.2 Bulk OUT Overview
- •8.1.9.3 Bulk IN Overview
- •8.1.9.4 Control Transfer Overview
- •8.1.9.5 Interrupt Transfer Overview
- •8.1.9.6 Isochronous Transfer Overview
- •8.1.10 Suspend and Resume
- •8.1.10.1 DWA Suspend and Resume
- •8.1.10.2 HWA Suspend and Resume
- •8.1.11 Reset Behavior
- •8.1.12 Device Control
- •8.1.13 Buffer Configuration
- •8.2 Descriptors
- •8.3 Requests
- •8.3.1 Wire Adapter Class-Specific Requests
- •8.3.1.1 Abort RPipe
- •8.3.1.2 Clear RPipe Feature
- •8.3.1.3 Clear Wire Adapter Feature
- •8.3.1.4 Get RPipe Descriptor
- •8.3.1.5 Get RPipe Status
- •8.3.1.6 Get Wire Adapter Status
- •8.3.1.7 Set RPipe Descriptor
- •8.3.1.8 Set RPipe Feature
- •8.3.1.9 Set Wire Adapter Feature
- •8.3.1.10 Reset RPipe
- •8.3.2 Notification Information
- •8.3.3 Transfer Requests
- •8.3.3.1 Control Transfers
- •8.3.3.2 Bulk and Interrupt Transfers
- •8.3.3.3 Transfer Completion Notification
- •8.3.3.4 Transfer Result
- •8.3.3.5 Abort Transfer
- •8.4 DWA Interfaces, Descriptors and Control
- •8.4.1 DWA Isochronous Streaming Interface
- •8.4.2 DWA Isochronous Streaming Overview
- •8.4.3 DWA Descriptors
- •8.4.3.1 Device Descriptor
- •8.4.3.2 Binary Device Object (BOS) Descriptor
- •8.4.3.3 Configuration Descriptor
- •8.4.3.4 Security Descriptors
- •8.4.3.5 Interface Association Descriptor
- •8.4.3.6 Data Transfer Interface Descriptor
- •8.4.3.7 Wire Adapter Class Descriptor
- •8.4.3.8 Notification Endpoint Descriptor
- •8.4.3.9 Notification Endpoint Companion Descriptor
- •8.4.3.10 Data Transfer Write Endpoint Descriptor
- •8.4.3.11 Data Transfer Write Endpoint Companion Descriptor
- •8.4.3.12 Data Transfer Read Endpoint Descriptor
- •8.4.3.13 Data Transfer Read Endpoint Companion Descriptor
- •8.4.3.14 Isochronous Streaming Interface Descriptor
- •8.4.3.15 Isochronous Streaming OUT Endpoint Descriptor
- •8.4.3.16 Isochronous Streaming OUT Endpoint Companion Descriptor
- •8.4.3.17 Isochronous Streaming IN Endpoint Descriptor
- •8.4.3.18 Isochronous Streaming IN Endpoint Companion Descriptor
- •8.4.3.19 Wire Adapter RPipe Descriptor
- •8.4.4 DWA Specific Requests
- •8.4.4.1 Clear Port Feature
- •8.4.4.2 Get Port Status
- •8.4.4.3 Set Isochronous Endpoint Attributes
- •8.4.4.4 Set Port Feature
- •8.4.5 DWA Notification Information
- •8.4.5.1 Remote Wake
- •8.4.5.2 Port Status Change
- •8.4.6 DWA Isochronous Transfers
- •8.4.6.1 DWA Isochronous OUT Responsibilities
- •8.4.6.2 DWA Isochronous IN Responsibilities
- •8.5 HWA Interfaces, Descriptors and Control
- •8.5.1 HWA Isochronous Streaming Overview
- •8.5.2 HWA Descriptors
- •8.5.2.1 Device Descriptor
- •8.5.2.2 Device_Qualifier Descriptor
- •8.5.2.3 Configuration Descriptor
- •8.5.2.4 Other_Speed_Configuration Descriptor
- •8.5.2.5 Security Descriptors
- •8.5.2.6 Data Transfer Interface Descriptor
- •8.5.2.7 Wire Adapter Class Descriptor
- •8.5.2.8 Notification Endpoint Descriptor
- •8.5.2.9 Data Transfer Write Endpoint Descriptor
- •8.5.2.10 Data Transfer Read Endpoint Descriptor
- •8.5.2.11 Wire Adapter RPipe Descriptor
- •8.5.3 HWA Specific Requests
- •8.5.3.2 Get BPST Adjustment
- •8.5.3.3 Get BPST Time
- •8.5.3.4 Get WUSB Time
- •8.5.3.5 Remove MMC IE
- •8.5.3.6 Set Device Encryption
- •8.5.3.7 Set Device Info
- •8.5.3.8 Set Device Key
- •8.5.3.9 Set Group Key
- •8.5.3.10 Set Num DNTS Slots
- •8.5.3.11 Set WUSB Cluster ID
- •8.5.3.12 Set WUSB MAS
- •8.5.3.13 Set WUSB Stream Index
- •8.5.3.14 WUSB Channel Stop
- •8.5.4 HWA Notification Information
- •8.5.4.1 BPST Adjustment Change
- •8.5.4.2 DN Received Notification
- •8.5.5 HWA Isochronous Transfers
- •8.5.5.1 HWA Isochronous OUT Responsibilities
- •8.5.5.2 HWA Isochronous IN Responsibilities
- •8.5.5.3 HWA Isochronous Transfer Completion
- •8.6 Radio Control Interface
- •8.6.1 Radio Control Descriptors
- •8.6.1.1 Radio Control Interface Descriptor
- •8.6.1.2 Radio Control Interface Class Descriptor
- •8.6.1.3 Radio Control Interrupt Endpoint Descriptor
- •8.6.2 Radio Control Command
- •8.6.2.1 Channel Change
- •8.6.2.2 Device Address Management
- •8.6.2.4 Reset
- •8.6.2.5 Scan
- •8.6.2.6 Set Beacon Filter
- •8.6.2.9 Set Notification Filter
- •8.6.2.10 Set TX Power
- •8.6.2.11 Sleep
- •8.6.2.12 Start Beaconing
- •8.6.2.13 Stop Beaconing
- •8.6.3 Radio Control Notifications
- •8.6.3.1 Application-specific Probe IE Received Notification
- •8.6.3.2 Beacon Received Notification
- •8.6.3.3 Beacon Size Notification
- •8.6.3.4 BPOIE Change Notification
- •8.6.3.5 BP Slot Change Notification
- •8.6.3.6 BP Switch IE Received Notification
- •8.6.3.7 Device Address Conflict Notification
- •8.6.3.8 DRP Availability Changed Notification
- •8.6.3.9 DRP Notification
- •A.1 Key Derivation
- •A.2 Handshake MIC calculation
- •A.3 Secure MMC (EO = payload length)
- •A.4 Data IN from device (EO = 2)
- •B.1 Descriptors for DWA
- •B.2 Descriptors for HWA
Chapter 8 |
|
Wire Adapter |
Wireless Universal Serial Bus Specification, Revision 1.0 |
8.5.2.8 Notification Endpoint Descriptor
This endpoint is used to report all the Wireless USB Device Notifications received by the HWA, Wire Adapter status and transfer completion notifications.
Table 8-46. Notification Endpoint Descriptor
Offset |
Field |
Size |
Value |
Description |
|
|
|
|
|
0 |
bLength |
1 |
7 |
Size of this descriptor in bytes, including this field. |
|
|
|
|
|
1 |
bDescriptorType |
1 |
5 |
ENDPOINT Descriptor Type |
2 |
bEndpointAddress |
1 |
Number |
The address of this endpoint |
|
|
|
|
|
3 |
bmAttributes |
1 |
Bitmap |
Interrupt endpoint of 00000011b. |
4 |
wMaxPacketSize |
2 |
40H |
Maximum packet size for this endpoint |
|
|
|
|
|
6 |
bInterval |
1 |
1 |
Interval for polling endpoint for data transfers. |
|
|
|
|
Expressed in frames or microframes depending on |
|
|
|
|
the device operating speed (i.e., either 1 millisecond |
|
|
|
|
or 125 μs units). |
|
|
|
|
|
8.5.2.9 Data Transfer Write Endpoint Descriptor
Table 8-47. Data Transfer Write Endpoint Descriptor
Offset |
Field |
Size |
Value |
Description |
|
|
|
|
|
0 |
bLength |
1 |
7 |
Size of this descriptor in bytes, including this field. |
|
|
|
|
|
1 |
bDescriptorType |
1 |
5 |
ENDPOINT Descriptor Type |
|
|
|
|
|
2 |
bEndpointAddress |
1 |
Number |
The address of this endpoint |
|
|
|
|
|
3 |
bmAttributes |
1 |
Bitmap |
BULK endpoint of 00000010b. |
|
|
|
|
|
4 |
wMaxPacketSize |
2 |
Number |
Maximum packet size this endpoint |
|
|
|
|
|
6 |
bInterval |
1 |
0 |
Polling not supported. |
|
|
|
|
|
8.5.2.10Data Transfer Read Endpoint Descriptor
Table 8-48. Data Transfer Read Endpoint Descriptor
Offset |
Field |
Size |
Value |
Description |
|
|
|
|
|
0 |
bLength |
1 |
7 |
Size of this descriptor in bytes, including this field. |
1 |
bDescriptorType |
1 |
5 |
ENDPOINT Descriptor Type |
|
|
|
|
|
2 |
bEndpointAddress |
1 |
Number |
The address of this endpoint |
3 |
bmAttributes |
1 |
Bitmap |
BULK endpoint of 00000010b. |
|
|
|
|
|
4 |
wMaxPacketSize |
2 |
Number |
Maximum packet size this endpoint |
6 |
bInterval |
1 |
0 |
Polling not supported. |
|
|
|
|
|
240
Chapter 8 |
|
Wire Adapter |
Wireless Universal Serial Bus Specification, Revision 1.0 |
8.5.2.11Wire Adapter RPipe Descriptor
The Wire Adapter RPipe descriptors are not returned as part of the configuration descriptor for an HWA. Host software can get each RPipe descriptor by sending a Get RPipe Descriptor (See Section 8.3.1.4) request to the HWA. The format of the Wire Adapter RPipe descriptor and the description of the fields are given in Table 8-49.
Table 8-49. Wire Adapter RPipe Descriptor
Offset |
Field |
Size |
Value |
|
Description |
|
|
|
|
|
|
0 |
bLength |
1 |
1CH |
Size of this descriptor in bytes, including this field. |
|
|
|
|
|
This is a read only field. |
|
1 |
bDescriptorType |
1 |
22H |
Wire Adapter RPipe Descriptor Type. This is a read |
|
|
|
|
|
only field. |
|
|
|
|
|
|
|
2 |
wRPipeIndex |
2 |
Number |
Number of this RPipe. Zero-based value identifying |
|
|
|
|
|
the index in the array of concurrent RPipes |
|
|
|
|
|
supported by this Wire Adapter. This is a read only |
|
|
|
|
|
field. |
|
|
|
|
|
|
|
4 |
wRequests |
2 |
Number |
The number of concurrent requests that can be |
|
|
|
|
|
assigned to this RPipe. This is a read only field. |
|
|
|
|
|
|
|
6 |
wBlocks |
2 |
Number |
The number of buffer blocks assigned to this RPipe. |
|
|
|
|
|
If the value in this field is zero then the Set RPipe |
|
|
|
|
|
Descriptor request can be used to set the number of |
|
|
|
|
|
blocks to be assigned to this RPipe. |
|
|
|
|
|
If the value in this field is not zero then the number |
|
|
|
|
|
of blocks assigned to this RPipe cannot be changed |
|
|
|
|
|
by host software. |
|
|
|
|
|
This field may be modified by host software if this is |
|
|
|
|
|
set to zero. |
|
|
|
|
|
|
|
8 |
wMaxPacketSize |
2 |
Number |
Maximum packet size that this RPipe will use to |
|
|
|
|
|
communicate with attached device. |
|
10 |
bHSHubAddress |
1 |
Number |
Reserved and must be set to zero. |
|
|
|
|
|
|
|
11 |
bHSHubPort |
1 |
Number |
This field specifies the device index where the |
|
|
|
|
|
device information buffer is present. |
|
|
|
|
|
|
|
12 |
bSpeed |
1 |
Number |
The PhyRate at which to communicate with the |
|
|
|
|
|
endpoint targeted by RPipe. The value and the |
|
|
|
|
|
associated rate is given in Section 5.6. |
|
13 |
bDeviceAddress |
1 |
Number |
Address of the attached device |
|
|
|
|
|
|
|
14 |
bEndpointAddress |
1 |
Number |
Endpoint Address to be used with this RPipe. |
|
|
|
|
|
Bit |
Description |
|
|
|
|
3:0 |
The endpoint number |
|
|
|
|
6:4 |
Reserved; set to zero |
|
|
|
|
7 |
Direction, ignored for control |
|
|
|
|
|
endpoints |
|
|
|
|
|
0 = OUT endpoint |
|
|
|
|
|
1 = IN endpoint |
|
|
|
|
|
|
241
Chapter 8 |
|
Wire Adapter |
Wireless Universal Serial Bus Specification, Revision 1.0 |
Table 8-49. Wire Adapter RPipe Descriptor (cont.)
Offset |
Field |
Size |
Value |
|
Description |
|
|
|
|
|
|
||
15 |
bDataSequence |
1 |
Number |
Current data sequence. This is the next data |
||
|
|
|
|
sequence value to be used when sending data to |
||
|
|
|
|
the endpoint that this RPipe is targeted at. |
||
|
|
|
|
|
||
16 |
dwCurrentWindow |
4 |
Number |
Current Window used for data sequence |
||
|
|
|
|
management and burst transfers. |
||
20 |
bMaxDataSequence |
1 |
Number |
Maximum sequence number that the endpoint |
||
|
|
|
|
supports. Valid values are 1 through 31. |
||
|
|
|
|
|
||
21 |
bInterval |
1 |
Number |
For Interrupt transfers this is the polling interval to |
||
|
|
|
|
be used by this RPipe in downstream |
||
|
|
|
|
communications |
|
|
|
|
|
|
For Isochronous transfers this is the logical service |
||
|
|
|
|
interval. |
|
|
|
|
|
|
See bInterval in Table 7-31 |
||
|
|
|
|
|
||
22 |
bOverTheAirInterval |
1 |
Number |
If the transfer type is Isochronous, then this field is |
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the interval for polling the downstream endpoint. |
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This field is Reserved and must be set to zero for all |
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other transfer types. |
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See bOverTheAirInterval in Table 7-32 for the |
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encoding of this field. |
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23 |
bmAttribute |
1 |
Bitmap |
Bit |
Description |
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|
1:0 |
Value |
Transfer Type |
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00B |
Control |
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01B |
Isochronous |
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10B |
Bulk |
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11B |
Interrupt |
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4:2 |
Transmit Power |
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See Section 5.2.1.2 for details on the |
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use of this field. |
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7:5 |
Data Burst Preamble Policy |
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See Table 5-7 for the encoding of |
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this field. |
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242
Chapter 8 |
|
Wire Adapter |
Wireless Universal Serial Bus Specification, Revision 1.0 |
Table 8-49. Wire Adapter RPipe Descriptor (cont.)
Offset |
Field |
Size |
Value |
|
Description |
|
|
|
|
|
|
24 |
bmCharacteristics |
1 |
Bitmap |
Transfer types supported on this RPipe |
|
|
|
|
|
Bit |
Description |
|
|
|
|
0 |
1: Control Transfer supported |
|
|
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|
|
0: Control Transfer NOT supported |
|
|
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1 |
1: Isochronous Transfer supported |
|
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|
|
0: Isochronous Transfer NOT |
|
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|
|
|
supported |
|
|
|
|
2 |
1: Bulk Transfer supported |
|
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|
|
|
0: Bulk Transfer NOT supported |
|
|
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|
3 |
1: Interrupt Transfer supported |
|
|
|
|
|
0: Interrupt Transfer NOT |
|
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|
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|
supported |
|
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|
|
7:4 |
Reserved |
|
|
|
|
This is a read only field. |
|
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|
|
|
|
25 |
bmRetryOptions |
1 |
Bitmap |
Bit |
Description |
|
|
|
|
3:0 |
Max Retry Count. The maximum |
|
|
|
|
|
number of times a transaction must |
|
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|
|
|
be retried before the transfer request |
|
|
|
|
|
is failed. |
|
|
|
|
|
The valid values are 0 through 15. A |
|
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|
|
value of zero in this field indicates |
|
|
|
|
|
that the HWA must not count errors |
|
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|
and there is no limit on the retries. |
|
|
|
|
|
For Isochronous transfers this field is |
|
|
|
|
|
set to zero. |
|
|
|
|
6:4 |
Reserved |
|
|
|
|
7 |
Low Power Interrupt. If this bit is |
|
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|
|
|
set, then this is a low power interrupt |
|
|
|
|
|
endpoint and the MaxRetryCount |
|
|
|
|
|
field is ignored. |
26 |
wNumTransactionErrors |
2 |
Number |
The HWA increments this field when it encounters |
|
|
|
|
|
an error while performing transactions to the |
|
|
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|
|
downstream endpoint targeted by this RPipe. |
|
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|
|
The host is responsible for resetting this field. |
|
|
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|
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|
|
All fields that are not marked read only may be changed by host software by using the Set RPipe Descriptor request.
243