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MATLAB to C Code Generation with

Embedded MATLAB

SahngHoh Kwon

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Agenda

Introduction– Challenges of the MATLAB-to-C workflow

What is Embedded MATLAB?– Benefits of the Embedded MATLAB workflow

How to use Embedded MATLAB?– Demonstration

– Tracking a moving object with a Kalman filter

Summary

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Traditional Concept to Implementation

Re-implementas you go down the level of abstraction

MATLAB code C/C++ codeAssembly code

HDL

This workflow requires you to:

maintain multiple copies of the same algorithm

fix and test across implementation boundaries

Workflow challenges:

time-consuming and error-prone

not scalable to the system level

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A better workflow would be…

One language

– No multiple copies of source code

– No redundant debugging and testing

One integrated design environment

– Integrated real-world design constraints in MATLAB

– Integrated visualization, analysis, and debugging

– Ease of porting individual algorithm IPs in MATLAB

Automatic code generation

– Path to embedded software ( MATLAB to C)

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Embedded

Embedded MATLAB is the subset of MATLAB for embedded algorithm

development

What Is Embedded MATLAB?

cellarrays

variable-sized data

objects

java

visualization

analysisarrays

struct

numeric

fixed-point

functions

nested functions

complex

sparse

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Features of Embedded MATLAB

Extensive function library– 300 MATLAB operators and functions

– 110 Fixed-Point Toolbox functions

– 40 Signal Processing Toolbox functions

Automatic C code generation – emlmex – Compiled C code from MATLAB code

– emlc – C source code from MATAB code

Reference functions on the MATLAB path– Enables partitioning of large Embedded MATLAB programs

Ability to call custom C code directly from your MATLAB function

Integration with Simulink and Stateflow

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Generating C Code Automatically

with Embedded MATLAB Subset

1. Examine your original MATLAB algorithm.

2. If necessary, modify it to conform with the Embedded MATLAB subset.3. Generate C code using the emlc command.

4. If necessary, iterate to optimize the MATLAB code for memory and

speed.

5. Verify easily within MATLAB.

Original

MATLAB

Code

Compliant

MATLAB

Code

Generate

C Code C Code

Optimize the MATLAB

Code

MEX

exe

lib

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Demo: Tracking a Moving Object with a

Kalman Filter

Using Embedded MATLAB

to generate C code directly

from MATLAB code

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Kalman Demonstration Workflow

1. Implement MATLAB algorithm with floating-point data types.

2. Convert MATLAB to MEX using emlmex function for fast

simulation and large test-set verification.

3. Convert MATLAB to C using emlc function for embedded

implementation.

4. Modify algorithm to handle packets (frames) of variable-sized

data.

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Variable-Size Data Supported in

MATLAB-to-C Code Generation

Define variable-size inputs, outputs, and local variables, with known

upper bounds.

Expands the scope of automatic C code generation for typical MATLAB

algorithm

Ensures static memory allocation in generated C code for variables that

change in size during execution

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Fixed-Point Acceleration: Introducing emlmex Function

Automatically generates C-MEX

function from MATLAB function

(MATLAB algorithm must

conform to Embedded MATLAB

language subset.)

Runs at compiled C-code

execution speed (may remove

speed bottlenecks)

Available with Fixed-Point

Toolbox

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C Code Generation from MATLAB: Introducing emlc Function

Automatically generates C source

code from your Embedded

MATLAB code, from the MATLAB

command line

Supports floating-point and fixed-

point variables with up to 128-bit

word-lengths

Uses only native C floating-point

and integer data types

Available with Real-Time Workshop

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Product Licensing Requirements

Capability Required Product

Generate embeddable C code using emlccommand

MATLAB, Simulink, and

Real-Time Workshop

Generate a compiled MATLAB executable (MEX) function using emlmex command

Fixed-Point Toolbox or

Simulink

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MATLAB®Simulink®

Embedded MATLAB™

codeEmbedded MATLAB™

functions

• Algorithm development

• Data analysis

• Advanced visualization

• Graphical models

• Time-based simulation

• Multi domain modeling

• System verification

HDL code

MathWorks Code Generation Products

Embedded C code

Domains

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Power of MATLAB in Simulink

Math-intensive algorithm

Easy conversion from MATLAB

Can build standalone simulation

applications

Call custom C code

C code or executable

Embedded MATLAB

runtime library

Simulink

Embedded MATLAB

Function

Embedded MATLAB™ functions

in Simulink®

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Demo: Inverse Kinematics of Robot

Manipulator

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pythagoras_lct.c

Calling External C Code from an

Embedded MATLAB™ Function

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Summary(1)

Embedded MATLAB is the subset of the MATLAB

language for embedded implementation

– 300 MATLAB operators and functions

– 110 Fixed-Point Toolbox functions

– 40 Signal Processing Toolbox functions

It narrows the concept-to-implementation design gap

– Automatic MATLAB-to-C translation

It makes “conceptual” MATLAB algorithm

“implementation-ready”

– Complying with Embedded MATLAB subset

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Summary(2)

emlc command – Automatically generate C source code from your compliant

MATLAB code directly from the MATLAB desktop

Embedded MATLAB Function block– Seamlessly integrate your Embedded MATLAB compliant

algorithm into Simulink

– Simulate the effect of your algorithm in the context of the

whole system

– Automatically generate C code using Real-Time Workshop

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For More Information

Embedded MATLAB Web page

– Description, demos, customer testimonials, technical info

– Links to related MathWorks products

– www.mathworks.com/products/featured/embeddedmatlab/

Webinars featuring Embedded MATLAB

– Generate C Code from MATLAB Functions Using the Embedded

MATLAB Subset www.mathworks.com/company/events/webinars/wbnr40173.html

MATLAB Central: User-contributed examples

– Look for “Embedded MATLAB”

– www.mathworks.com/matlabcentral