Step 1: Set up the Import Function Example

Step 1: Set up the Import Function Example - 2021.2 English

Vitis Model Composer Tutorial (UG1498)

Document ID

UG1498

Release Date

2021-11-29

Version

2021.2 English

In the MATLAB Current Folder panel, navigate to ug1498-model-composer-sys-gen-tutorial\HLS_Library\Lab2\Section1 folder.

Double-click the basic_array.cpp and basic_array.h files to view the source code in the MATLAB Editor.
These are the source files for a simple basic_array function in C++, which calculates the sum of two arrays of size 4. You will import this function as a Vitis Model Composer block using the xmcImportFunction function.

The input and output ports for the generated block are determined by the signature of the source function. Vitis Model Composer identifies arguments specified with the const qualifier as inputs to the block, and all other arguments as outputs.

Note: For more details and other options for specifying the direction of the arguments, see the Vitis Model Composer User Guide (UG1483).

Important: You can use the const qualifier in the function signature to identify the inputs to the block or use the pragma INPORT.

In the case of the basic_array function, the in1 and in2 arguments are identified as inputs.
```
void basic_array(
   uint8_t out1[4], 
   const uint8_t in1[4], 
   const uint8_t in2[4])
```
To learn how to use the xmcImportFunction function, type help xmcImportFunction at the MATLAB command prompt to view the help text and understand the function signature.
Open the import_function.m MATLAB script, and fill in the required fields for the xmcImportFunction function in this way:
```
xmcImportFunction('basic_array_library', {'basic_array'}, 'basic_array.h', {'basic_array.cpp'}, {});
```
The information is defined as follows:

Library Name

basic_array_library. This is the name of the Simulink library that is created with the new block.

Function Names

basic_array. This is the name of the function that you want to import as a block.

Header File

basic_array.h. This is the header file for the function.

Source Files

basic_array.cpp. This is the source file for the imported function.

Search Paths

This argument is used to specify the search path(s) for header files. In this example, there are no additional search paths to specify and hence you can leave it as { } which indicates none.

Note: Look at import_function_solution.m in the solution folder for the completed version.
Run the import_function.m script from the MATLAB command line:
```
>>run('import_function.m')
```
Notice that a Simulink library model opens up with the generated block basic_array.

Save this Simulink library model.
Double-click the basic_array block, and look at the generated interface.
The following figure shows the Block Parameters dialog box for basic_array:
Open the test_array.slx model, which is just a skeleton to test the generated block.
Add the generated basic_array block into this model, then connect the source and sink blocks.
Simulate this model and observe the results in the display block.