1. Integrating Bluetooth on low-power buses
11/18/ :33 PM
HW-255T
Integrating Bluetooth on low-power buses
Abhinav Gupta
Program Manager
Microsoft Corporation
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

2. Agenda Transport connectivity – challenges & goals
Delivering great Bluetooth experiences
Sample Bluetooth integration
You’ll leave with examples of how to
Develop for Bluetooth connectivity using low-power transports
Incorporate vendor-specific customizations

3. Improved power efficiency calls for lower power Bluetooth transport connectivity.

4. Transport connectivity – challenges & goals
USB controllers are scarce & targeted for higher-bandwidth apps
Goal: provide a transport extensibility model so you have connectivity options
Bluetooth controllers using lower power buses rely on vendor-specific customizations
Goal: enable implementation flexibility so integration is easy for you

5. Transport connectivity – challenges & goals
Performance impact when using lower power transports
Goal: ensure higher-layer Bluetooth scenarios remain transport agnostic so you can deliver the same experiences
Voice-based scenarios have stricter latency requirements
Goal: support an alternate voice channel (offloading) so you can achieve optimal audio quality while further reducing power

6. Bluetooth on QC and TI ARM platforms
11/18/ :33 PM
demo
Bluetooth on QC and TI ARM platforms
Tablet with several Bluetooth peripherals
Speakers – listening to music
HID – using a keyboard & mouse
Bluetooth transport: high-speed UART
© 2010 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

7. Sample Bluetooth integration

8. Windows 7 stack architecture
A look at Windows 7
USB Bluetooth controller support
BthPort.sys: core driver
BthUSB.sys: USB miniport driver
Enumeration via PnP
Inbox profiles
HID, OPP, PAN, HCRP, SPP, DUN
BthPort.sys
SDP
L2CAP
SCO
HCI
BthUSB.sys
USB port driver
Bluetooth controller
MSFT component
3rd party H/W

9. Windows 8 stack architecture
A look at Windows 8
Transport connectivity options
BthMini.sys: extensible driver
Transport driver: vendor-supplied
Controller drivers: meant for data I/O, power up & idle/wake
Enumeration via ACPI
ACPI table definition
Enables for the same driver to be used across platforms
BthPort.sys
BthMini.sys
BthUSB.sys
Bluetooth transport driver
Framework extensions
USB port driver
Controller driver(s)
Bluetooth controller
Vendor component
3rd party H/W
MSFT component

10. Sample system connectivity
System designer – required controllers:
Data I/O
Power on/off
Idle/wake signaling
(Bluetooth enable, host wake)
Chosen controllers:
HS-UART
I2C
GPIO
System core
I2C
GPIO
GPIO
HS-UART
BT_ENABLE
DATA_IO
HOST_WAKE
Bluetooth controller
POWER
Power Management IC

11. Sample ACPI description for Bluetooth
Device (BTH0) {
Name (_HID, "ABCD_BTH") //where "ABCD" is vendor name;
Method (_CRS, 0x0, NotSerialized)
Name (RBUF, ResourceTemplate()
//UART Serial Bus Descriptor
UARTSerialBus (0xC0, LittleEndian, DataBitsEight, StopBitsOne, FlowControlHW,
115200, 480, 32, ParityTypeNone, "\\_SB.UAR1", , )
//I2C Descriptor
...
//GPIO Descriptor })
Return (RBUF) }

12. Sample stack architecture
Dependent controller drivers
UART, I2C, GPIO
Based on frame extensions (Cx)
WDK samples – easier development
Bluetooth transport driver
KMDF WDK sample – UART
Vendor supplied for:
Device configuration (& F/W update)
Power up & idle/wake
Combo-chip support
Radio on/off
BthPort.sys
BthMini.sys
Bluetooth transport driver
Bluetooth UART transport driver
UART Cx
Framework extensions
I2C Cx
GPIO Cx
Controller driver(s)
UART driver
I2C driver
GPIO driver
Bluetooth controller
Vendor component
3rd party H/W
MSFT component

13. Sample device configuration
Setting up the Bluetooth controller
Configuration done through vendor-specific commands
Enabling implementation flexibility
Integrated within transport driver
Separate initialization library
BthPort.sys
BthMini.sys
Initialization Lib
Bluetooth UART transport driver
UART Cx
I2C Cx
GPIO Cx
UART driver
I2C driver
GPIO driver
Bluetooth controller
Vendor component
3rd party H/W
MSFT component

14. Core stack device power states & transitions
How does the Bluetooth stack achieve energy efficiency?
You can leverage this behavior and easily integrate it into your designs S0
D0: Active
WAKE
D2: Low Duty Cycle ON
IDLE Sx
D3: Off
OFF

15. Sample Bluetooth power-up & idle/wake
I2C – Bluetooth power on
GPIO – Bluetooth enable
Idle
GPIO – armed for wake
GPIO – Bluetooth disable
Wake
GPIO – Host wake detected
System core
I2C
GPIO
GPIO
GPIO
GPIO
HS-UART
BT_ENABLE
DATA_IO
HOST_WAKE
Bluetooth controller
POWER
Power Management IC

16. Sample combo-chip & radio on/off support
More radios becoming integrated
Sample combo-chip device
Transport driver now a bus driver
Can accommodate for changing H/W configurations
Radio on/off
A unified radio management experience across system components
Vendor-provided DLL is easy to integrate
BthPort.sys FM
GPS
Radio manager
BthMini.sys
Bth on/off DLL
UART bus driver
Bluetooth transport driver
UART Cx
I2C Cx
GPIO Cx
UART driver
I2C driver
GPIO driver
Multi-function device (BT/FM/GPS)
Vendor component
3rd party H/W
MSFT component
User-mode component

17. Bluetooth profile support

18. Supported profiles Inbox profiles
HID, PAN, OPP (file transfer), HCRP (print)
HFP (with sideband support), A2DP, AVRCP
Partners can develop profiles on top of the stack

19. Sample sideband SCO audio (voice) support
Voice has strict latency requirements
Isochronous channel in USB ensures on-time delivery
Low-power buses don’t have a prioritization concept
Rely on an I2S/PCM channel for improved audio quality
Enabling flexibility in the HFP driver
USB: operates in “in-band” mode
Low-power buses: operates in “side-band” mode
3rd party app (e.g. Skype)
Audio core
CallButtons API
Audio driver
HFP driver
Bluetooth stack
Transport driver
Bluetooth controller
I2S
HS-UART
MSFT component
Vendor component
3rd party H/W

20. Performance & CPU utilization (back to the demo)

21. Performance & CPU utilization analysis
File transfer (object push profile) – receive & transmit scenarios
Internal HS-UART (no DMA) vs. external USB radio on the same platform
For about the same throughput, CPU utilization is higher for USB
Throughput
CPU Utilization
USB: ~68% more
USB: ~17% faster
USB: ~2% faster
USB: ~6% more

22. Windows certification for Bluetooth
Our stack provides a platform so you can easily integrate and innovate
Benefit from tight integration with the power management framework
Leverage inbox experiences and develop more higher-layer profiles
We need your help in designing Bluetooth controllers that deliver the highest quality experiences to our customers

23. Final remarks
Developed for Bluetooth connectivity using low-power transports
Bluetooth stack is enabling implementation ease & flexibility around:
Transport connectivity, device configuration, power-up & idle/wake signaling, combo-chip support, and unified radio management
Bluetooth stack is delivering key end-user experiences

24. Call to action Meet certification requirements for your system
Follow extensible transport Bluetooth bring-up guidelines:
ACPI table description – device properties & interconnectivity
Bluetooth transport/bus driver
Dependent controller drivers
Audio driver

25. Related sessions [Session 774] Building great Windows 8 systems
[Session 251] Introducing low-power buses for Windows 8
[Session 254] Connecting Bluetooth Low Energy devices to Windows

26. Further reading and documentation
Bluetooth Extensible Transport Enumerations
Bluetooth Extensible Transport Structures
Bluetooth Extensible Transport IOCTLs
Bluetooth Software Radio Switch Function Prototypes
Bluetooth Devices Reference
Windows Hardware Dev Center
Windows Dev Center
More about Bluetooth

27. thank you Feedback and Questions: http://forums.dev.windows.com
Session Feedback:

28. 11/18/ :33 PM
© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2011 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.