Cirrus Logic AN348 User Manual
AN348
Application Note
GETTING STARTED WITH THE AUDIO DSP EVALUATION
KITS FROM CIRRUS LOGIC
1. INTRODUCTION
The following sections will provide step-by-step instructions to explain how to get started with the Evaluation Kits for Audio DSP
products from Cirrus Logic. This is a generic document as its principle applies to all current Audio DSP families from Cirrus Logic
— the CS48500, the CS470xx Audio SoCs, and the CS49531x / 4970xx.
An advanced audio processing design is created and will be used as an example to illustrate the practical work with the
DSP Composer™ tool and a CDB48560 evaluation board. The given e xample is more complex than the example projects
included in the evaluation board software package. It also shows how to use the pre-defined blocks and primitives when using
the DSP Composer GUI.
A Q&A section is included at the end of this document.
2. GETTING STARTED
2.1 Up-front information and preparation
Please prepare the following essential information about your target application before co ntacting Cirrus Log ic:
• The basic technical design requirements including any 3rd party IP support such as the support of specific multichan nelaudio formats or standards.
• The general project schedule and anticipated volume information.
• Your contact details.
With these details on hand, your local Cirrus Logic Distribution partner or sales offices can easily identify the 'best fit' Audio DSP
for your application. Cirrus Logic offers a great variety of Audio DSP-products, which are widely compatible — whether your
design needs a cost-effective, entry-level audio DSP such as a CS48500-DSP or a high-performance multichannel audio decoder
such as the CS49700.
If applicable, Cirrus Logic needs to contact the relevant third party to get approval prior to providing samples or software.
Please contact your local Cirrus Logic sales representative or Distribution partner for details.
The evaluation board software is provided on the Cirrus Logic web site http:/www.cirrus.com
specific to the DSP of your choice and browse to the Resources section.
Within the software suite, you will only have access to modules and functions for which you have appropriate licences in place.
If you require access to disabled blocks, you will need to obtain the licences from the third-party licensor first before Cirrus Logic
is authorized to send you the specific code.
Cirrus Logic provides comprehensive technical documentation such as evaluation board manuals, data sheet specifications, or
application notes which will be installed during the evaluation board software setup. The default path for all documents is
C:\CirrusDSP\doc\. Note that application notes for the individual processing blocks such as for third-party, IP-based decoders are
provided with the individual setup files.
. Please refer to the web site section
All Cirrus Logic DSPs are SRAM-based and can be upgraded in the field or during evaluation.
Copyright Cirrus Logic, Inc. 2011
http://www.cirrus.com
(All Rights Reserved)
MAR ‘11
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2.2 The Essential Set-up
The evaluation boards are connected to standard PCs with Windows XP® operating systems via USB. After a successful
installation of the evaluation board software, the DSP Composer GUI can be started. Your computer screen should look like the
following:
The GUI can also be used in emulation mode (without any evaluation board connected to the host PC).
Please refer to theCDB48500-USB Evaluation Kit guide from Cirrus Logic for a basic introduction to the minimum hardware set-
up. This is available at http://www.cirrus.com
START
Program Files Cirrus Logic DSP menu after installation.
. These specifications are also accessible per the
2.3 Using the DSP Composer GUI, Project Example
This section shows how to build a project with multiple audio I/Os and some customized audio processing using the DSP
Composer GUI.
Let us consider designing an audio system with the following features:
• 4 Analog Inputs, 6 Analog Outputs
• Customized Audio Processing Chain as Follows:
- High-pass and low-pass filters for the input channels
- Mixer with 4 inputs to create 6 output channels
- 6-channel, 4-band parametric EQ
- Sine wave test-tone generator
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First, drag the SYSTEM block from the menu on the left-hand side. When positioning the SYSTEM block on the virtual workspace
or canvas, some parameters can be set. Please leave everything set to default for now.
Next, we define the audio inputs and outputs by another simple drag-and-drop operation. Fo r thi s example, le t us select anal og
inputs for the input block in the Properties menu and some analog outputs per the default settings.
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Your workspace or canvas shoul d no w lo ok similar to this:
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Our example project does not include any matrix decoders or virtualizing modules.
Therefore, we select the corresponding Passthru-Matrix processing module (MPM) and Passthru-Virtual processing module (or
VPM) from the selection menu on the left-hand side to allow a simple pass-through function.
The next step is to start with creating our own custom Post Processing module (PPM). Drag the Custom PPM block on to the
canvas. Here we have named the block My PPM. We also need to add another final stage — the audio manager module, which
can be found under Standard PPM elements. This connects the My PPM module to the audio outputs.
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