1. HD Audio 1.1 Overview David Flenniken
Software Design Engineer Windows Media Devices Group microsoft.com
Microsoft Corporation
Soccer Liu
Software Design Engineer Windows Media Devices Group microsoft.com
Microsoft Corporation

2. Session Outline HD Audio Codec Configurability
Role of the Topology Parser
How the Topology Parser works
Programming Pin Configuration Registers
Common Device Experience
Validating Pin Configuration

3. HD Audio Codec Configurability
Configuration
Default Setting 1
Configuration
Default Setting 2

4. Role of Topology Parser
HD Audio Class Driver 3 rd
Party
HD Audio Driver
Codec C
specific
Topology Parser (
static lib )
Knowledge
Provided by
IHV and ODM
Microsoft
HD Audio Codec
HD Audio Codec
HD Audio Codec

5. How HD Audio Class Driver Solve This Problem
Microsoft develops a HD Audio Topology Parser that handles HD audio codec’s topology parsing for all HD Audio specification compliant codecs
HD Audio Class Driver 1.1 statically links to Topology Parser lib to solve topology parsing issues

6. What Parser Does

7. 3rd Party IHVs Can Also Use Topology Parser
3rd party driver can take advantage of Topology Parser by linking to this static library to replace their own parsing logics to simplify driver code
This Topology Parser will be released in the form of a static library. Its DDI is planned to be published when HD Audio Class Driver shipped in late 2005.

8. Role of Topology Parser3 rd
Party
HD Audio Driver
HD Audio Class Driver 3 rd
Party
HD Audio Driver
Codec C
specific
Topology Parser (
static lib )
Topology Parser (
static lib )
Knowledge
Provided by
IHV and ODM
Microsoft
HD Audio Codec
HD Audio Codec
HD Audio Codec

9. How Topology Parser Works?
Enumerate all audio paths
Build Association list
Enumerate all Pin Path Combinations for each association
Prioritize combinations found
Pick the best Association Resource Mapping

11. Enumerate All Audio Paths
Audio path: a path that audio data could flow through starting at a resource widget and ending at a pin widget
Not all the possible paths are valid. There are rules set by parser for what an invalid audio path is.
Invalid audio paths:
Paths including loop
Paths including Vendor Defined Widget
Paths ending with a pin widget that has no physical connection
Output audio paths ending with input Pin
Input audio paths ending with output Pin
Paths contains widgets sitting between resource widget and HD Audio Link
Paths do not end with a pin widget

13. Valid Audio Paths Found

14. Build Association List
Zero is not a valid Association Default number (Pin 15)

15. Enumerate All Pin Path Combinations for Each Association
Pin 11  Path 6 (6-D-11)
Pin 18  Path 8 (7-E-18)
Association 4
Pin 14  Path 9 (B-14)
Association 1
Pin 10  Path 1 (5-C-10)
Pin 11  Path 6 (6-D-11)
Pin 18  Path 8 (7-E-18)
Association 4
Pin 14  Path 10 (19-14)
Association 1
Pin 10  Path 5 (6-D-10)
Pin 11  Path 2 (5-C-11)
Pin 18  Path 8 (7–E-18)
Association 4
Pin 14  Path 9 (B-14)
Association 1
Pin 10  Path 5 (6-D-10)
Pin 11  Path 2 (5-C-11)
Pin 18  Path 8 (7–E-18)
Association 4
Pin 14  Path 10 (19-14)

16. Prioritize Combinations Found
Base on a set of predefined rules to give each path the appropriate weight. Set the sum of weighted priority value to each Association Resource Mapping.
The rules are:
The lower the association number, the higher its priority
Known device types have higher priority than unknown device types
A path with a wider volume control range has higher priority

17. Pick the Best Association Resource Mapping
The highest sum of all weighted paths and associations will be chosen as the best Association Resource Mapping for final output. 1`
Association 1
Pin 10  Path 1 (5-C-10)
Pin 11  Path 6 (6-D-11)
Pin 18  Path 8 (7-E-18)
Association 4
Pin 14  Path 9 (B-14)

20. Use of Parser Output
The Class Driver uses the parser's output to program widget connections and settings
For each logical device, class driver builds a Windows Kernel Streaming filter to expose its audio functionality to system

21. Programming Pin Configuration Registers
The Microsoft Topology Parser relies on spec compliant HD Audio codecs
Follows Microsoft UAA “Pin Configuration Guidelines for High Definition Audio Devices” to ensure proper Pin Configuration Default settings

22. Detailed Pin Configuration register fields
Port Connectivity
Location
Default Device
Connection Type
Color
Misc.
Default Association
Sequence

23. Port Connectivity Field
Used to indicate existence
The Pin Widget can be either an external Jack or a fixed function device (like internal speakers) or it can be unconnected
0x1 means no physical connection
The Class Driver ignores Pin Widgets with this value set to 0x1

24. Location Field Denotes Physical location of the Pin Widget
Set as appropriate
The Class Driver uses this information to describe the jack location to the end user

25. Default Device Field
The Class Driver uses Default Device field to determine what Logical Device to create
The Class Driver recognizes the following:
Line Out, Speaker, HP Out, S/P-DIF Out, Line In, Mic In, CD, Aux and S/P-DIF In
Other devices supported by the parser
Digital Other Out and Digital Other In
Not currently supported
Modem Line Side, Modem Headset Side, Telephony, and Other

26. Interpretations and Clarifications
Specific Widget types
Line out - No build-in amplifier on the codec
Speaker - No build-in amplifier on the codec, but there is an external amp connected.
HP Out – There is a programmable build-in amplifier on the codec that can drive headphones. If the amp is turned off, the Pin acts like a Line Out pin (above)

27. Connection Type Field Set as appropriate
Largely ignored by the Class Driver

28. Color Field 16 possibilities – use them
Colors should be unique to each location
Pin with internal location should be set to color unknown (0x0)
The Class Driver uses this in it’s description of the jacks to the end user

29. Misc. Field Jack Detect Override
0 means enabled
System must provide “Audio Jack Detection Circuits” before setting to 0.
1 means override (disabled)
This field should be enabled to empower dynamic device functionality

30. Default Association Field
Labels the priority of the Pin Widget
Lower numbers mean higher priority
Association 0 is invalid
0xF means the pin is not associated to any other pin
The Class Driver uses this field to:
Indicate groupings for multi-pin logical devices
Resolve resource disputes (higher priority device wins)

31. Sequence Field Orders pins in an association
All sequence numbers in an association must be unique
The Class Driver generally uses this field to determine how to map channels in a multi-channel device.

32. Sequence Number Meanings
Ordering in HD Audio Spec 1.0
Location information is missing
The Class Driver assigns meanings for clarity
0 means Front Left & Front Right
1 means Front Center & Low frequency
2 means Back Left & Back Right
3 means Front Left of Center & Front Right of Center
4 means Side Left & Side Right
Special meanings (examples)
(0,2) or (0,4) means Quadraphonic
(0,1,2) means Surround Sound Speakers
(0,1,2,4) means Home Theater Speakers
See Pin Config Guidelines for more info

33. Common Device Experience
Supported
Render
Line out, Speaker, Headphone and S/P-DIF Out
Capture
Microphone, LineIn, CDIn, AuxIn and S/P-DIF In
Not Supported
Digital Other Out, Modem Line Side, Modem Handset side, Telephony, Digital Other In or Other (or Reserved)

34. Render Device
Can’t mix Line Out widgets and Speaker widgets in the same association
Generally, there are 1 to 4 pins in a render logical device association
Sequence numbers determine channel mapping
Single pin render devices
Headphone
Line out
Speaker

35. Single Pin Devices S/P-DIF Out Device Line In Device Aux In Device
No analog functionality on audio path
Line In Device
Aux In Device
CD Device
S/P-DIF In Device
Microphone Device

36. Multi Purpose Devices Muxed Capture Device Mixed Capture Device
A collection of mutually exclusive input devices that share the same ADC
Mixed Capture Device
A collection of devices that share the same ADC that may work at the same time
Redirected Headphone Render Device
Combination render + headphone device where when the headphone is plugged in the output is redirected from the speakers to the headphone

37. Validate Pin Configurations
Parser relies on the Pin Configuration Default for successful parsing – getting them set right is very important
Use UAATest.exe
It validates Pin Configuration Default settings
It exercises the same parser logics to validate codecs and exposes audio paths
UAATest also checks HD Audio Spec compliance
Let Microsoft know about inconsistencies (or issues with the output)

38. Call to Action
Use Microsoft Topology Parser to simplify and unify yours HD Audio device driver support
Follow guidelines in “Pin Configuration Guidelines for High Definition Audio Devices” for HD Audio Codec Pin Configuration Default programming
Help your OEM/ODM customers expose parser supported device types through system BIOS programming of HD Audio Pin Configuration Default values
Build UAA class driver compatible HD Audio solutions

39. Email uaa @ microsoft.com for
Additional Resources
microsoft.com for
Microsoft UAA Pin Configuration Guidelines for High Definition Audio Devices, Release date TBD
UAA Hardware Design Guideline White Paper
UAATest.exe
Microsoft UAA overview white paper on