Convert Fixed-Point Conversion Project to MATLAB Scripts

This example shows how to convert a MATLAB^® Coder™ project to MATLAB scripts when the project includes automated fixed-point conversion. You can use the -tocode option of the coder command to create a pair of scripts for fixed-point conversion and fixed-point code generation. You can use the scripts to repeat the project workflow in a command-line workflow. Before you convert the project to the scripts, you must complete the Test step of the fixed-point conversion process.

• Prerequisites

• Generate the Scripts

• Run Script That Generates Fixed-Point C Code

• Run Script That Generates Fixed-Point MATLAB Code

Prerequisites

This example uses the following files:

• Project file ex_2ndOrder_filter.prj

• Entry-point file ex_2ndOrder_filter.m

• Test bench file ex_2ndOrder_filter_test.m

• Generated fixed-point MATLAB file ex_2ndOrder_filter_fixpt.m

To obtain these files, complete the example Propose Fixed-Point Data Types Based on Simulation Ranges, including these steps:

1. Complete the Test step of the fixed-point conversion process.

2. Configure the project to build a C/C++ static library.

Generate the Scripts

1. Change to the folder that contains the project file ex_2ndOrder_filter.prj.

2. Use the -tocode option of the coder command to convert the project to the scripts. Use the -script option to specify the file name for the scripts.

   coder -tocode ex_2ndOrder_filter -script ex_2ndOrder_filter_script.m

   The coder command generates two scripts in the current folder:

   ex_2ndOrder_filter_script.m contains the MATLAB commands to:

   • Create a code configuration object that has the same settings as the project.

   • Run the codegen command to convert the fixed-point MATLAB function ex_2ndOrder_filter_fixpt to a fixed-point C function.

   The fixedPointConverter command generates a script in the current folder. ex_2ndOrder_filter_script_fixpt.m contains the MATLAB commands to:

   • Create a floating-point to fixed-point conversion configuration object that has the same fixed-point conversion settings as the project.

   • Run the codegen command to convert the MATLAB function ex_2ndOrder_filter to the fixed-point MATLAB function ex_2ndOrder_filter_fixpt.

     The suffix in the script file name is the generated fixed-point file name suffix specified by the project file. In this example, the suffix is the default value _fixpt.

   The coder command overwrites existing files that have the same names as the generated scripts. If you omit the -script option, the coder command writes the scripts to the Command Window.

Run Script That Generates Fixed-Point C Code

To run the script that generates fixed-point C code from fixed-point MATLAB code, the fixed-point MATLAB function specified in the script must be available.

1. Make sure that the fixed-point MATLAB function ex_2ndOrder_filter_fixpt.m is on the search path.

    addpath c:\coder\ex_2ndOrder_filter\codegen\ex_2ndOrder_filter\fixpt

2. Run the script:

    ex_2ndOrder_filter_script

   The code generator creates a C static library with the name ex_2ndOrder_filter_fixpt in the folder codegen\lib\ex_2ndOrder_filter_fixpt. The variables cfg and ARGS appear in the base workspace.

Run Script That Generates Fixed-Point MATLAB Code

If you do not have the fixed-point MATLAB function, or if you want to regenerate it, use the script that generates the fixed-point MATLAB function from the floating-point MATLAB function.

1. Make sure that the current folder contains the entry-point function ex_2ndOrder_filter.m and the test bench file ex_2ndOrder_filter_test.m.

2. Run the script.

    ex_2ndOrder_filter_script_fixpt

   The code generator creates ex_2ndOrder_filter_fixpt.m in the folder codegen\ex_2ndOrder_filter\fixpt. The variables cfg and ARGS appear in the base workspace.