Automotive Audio Processing
Reference Design
from DSP Concepts
A Complete Audio Processing Solution
This reference design from DSP Concepts provides all of the audio signal processing needed by a
typical high-end automotive amplifiers and head units. The solution is targeted at automotive
audio suppliers and works in conjunction with a real-time framework and control software. The
flexible software supports many different operating systems and network types including MOST
and CAN. The comprehensive tool chain is based around the Audio Weaver development
environment and includes a graphical signal flow editor, real-time tuning, automated testing, and
MIPs and memory profiling. Dynamic instantiation allows the personality of an amplifier to be
changed without modifying the underlying executable image. The signal flow and tuning
parameters are stored as a data file in flash memory thereby allowing a single amplifier platform to
be leveraged for multiple customers and car models. Starting with our reference design drastically
reduces your development time and cost!
Highlights
Graphical signal flow
development
Large library of
optimized audio
modules
Real-time tuning
over a variety of
interfaces
Dynamic
instantiation
Extensible custom
module API
MATLAB automation
interface
Hardware in the loop
testing
Flexible APIs
compatible with
different RTOS's
Native PC execution
for prototyping and
predevelopment
The reference design supports SHARC and Blackfin processors from Analog Devices. The fixedpoint Blackfin processor is suitable for entry-level and medium complexity designs; the floatingpoint SHARC processor is the choice for high-end systems.
Audio Weaver Development Environment
Audio Weaver is a full featured development environment aimed at the particular requirements of
embedded audio developers. It codifies years of audio product development experience and
enables algorithm and product developers to more quickly and efficiently develop products and
technology. Audio Weaver consists of a graphical signal flow editor coupled with a large library of
over 250 audio processing modules. The module library was designed with the needs automotive
audio suppliers in mind and includes parametric EQs; highpass, lowpass, and allpass filters;
loudness compensation; delays; compressors; limiters; gain controls; and much, much more.
Most modules are implemented using 32-bit floating-point processing. Extended precision 40-bit
filters are provided for challenging low frequency correction. All of the necessary filter design
rd
equations are included. Algorithms from 3 party suppliers, like Dolby and DTS, are also
available.
Advanced users can extend Audio Weaver's capabilities in several ways. The MATLAB
automation API allows Audio Weaver to be controlled by MATLAB – the industry standard
language for signal processing professionals. Leverage MATLAB for automated testing,
measurement, filter design, and tuning. MATLAB is particularly useful in production environments
where a high level of automation is required. Audio Weaver's Custom Module API allows you to
extend the audio module library by writing your own custom audio processing functions.
Automotive Audio Processing Reference Design
Audio Weaver Features
Drag and drop signal flow editor
Graphical inspectors for tuning
Native PC execution for prototyping and
predevelopment
Real-time tuning over USB, SPI, or RS-232
Generates efficient code
Includes all necessary filter and coefficient
design equations
Flash memory support
MIPs and memory profiling
Full regression testing capabilities (requires
MATLAB)
Subsystems with hierarchical design
Multirate processing support
Multichannel support
Smoothed version of most modules for clickless
operation
Requires a PC with Windows XP or Vista
Automation API requires MATLAB 2009a or
later
Consulting Services
Integration support
Custom tuning interfaces
Custom module development
Supported Blackfin Hardware
Blackfin 527 EZ-KIT
o USB tuning interface
o 2 in – 2 out analog I/O at 48 kHz
Blackfin 533 EZ-KIT w/USB daughter card
o USB tuning interface
o 4 in – 6 out analog I/O at 48 kHz
Blackfin 537 EZ-KIT
o RS-232 tuning interface
o 2 in – 2 out analog I/O at 48 kHz
Blackfin 537 EZ-KIT w/Audio Extender board
o RS-232 tuning interface
o 8 in – 16 out analog I/O at 48 kHz
o S/PDIF I/O
Blackfin BF548 EZ-KIT
o USB tuning interface
o 2 in – 6 out analog I/O at 48 kHz
Audio Module Library Details
Absolute value
Adder
Asymmetric clip
Automatic Gain Control
Balance
Biquad
Biquad Cascade
Biquad smoothed
Butterworth filters (highpass, lowpass, and
allpass). 32-bit and 40-bit versions.
Compressor
Crossovers: Linkwitz-Riley and Butterworth
dB10, db20, undb10, undb20
Decimator and interpolator
Delays: single and multi-tap
Demultiplexor
FIR filters
FIR interpolator and decimator utilizing
polyphase
General purpose 2nd order filter design
(parametric, allpass, notch, shelf, etc.)
Graphic equalizer
Limiter
LMS adaptive filter
Math Library
Metering: peak and RMS
Mixers
Multiplexor and router. Smoothed and
unsmoothed versions
Mute
Polynomial nonlinearity
RMS
Sawtooth generator
Signal statistics
Sine wave generator
Single and multichannel scalers
Square
Sqrt
Subtract
Sum / Difference
Table lookup
Three band tone control
Volume control with built-in loudness
compensation
White noise and pink noise generators
Supported SHARC Hardware
SHARC 21364 EZ-KIT
o SPI tuning interface
o 2 in – 8 out analog I/O at 48 kHz
SHARC 21369 EZ-KIT
o RS-232 tuning interface
o 2 in – 8 out analog I/O at 48 kHz
SHARC 21469 EZ-KIT
o RS-232 tuning interface
o 4 in – 8 out analog I/O at 48 kHz
TM
dsprak from Danville Signal
o 21369 processor
o Configurable I/O
Audio Weaver Demo board from Danville
Signal
o USB tuning interface
o 21371 processor
o 2 in – 4 out analog I/O up to 96 kHz
1800 Wyatt Drive,
Suite 14,
Santa Clara, CA 95054
Tel: +1-408-747-5200
Fax: +1-408-716-2496
info@dspconcepts.com
www.dspconcepts.com
Also Available for the
ARM Cortex-A family