C Construct

void add_function(void)
{ 
   y1 = u1 + u2;
}

Procedure

1. Open example model ex_function_call.

The subsystem has two inputs and returns one output.

Selecting the Treat as atomic unit parameter enables parameters on the Code Generation tab. The Code Generation tab provides these customizations:

2. To build the model and generate code, press Ctrl+B.

Results

In ex_function_call.c, the function is called from ex_function_call_step:

/* Model step function */
void ex_function_call_step(void)
{
  /* Outputs for Atomic SubSystem: '<Root>/Add_Subsystem' */
  add_function();

  /* End of Outputs for SubSystem: '<Root>/Add_Subsystem' */
}

The function prototype is externally declared through the subsystem file, add_function.h:

extern void add_function(void);

The function definition is in the subsystem file add_function.c:

void add_function(void)
{
  /* Outport: '<Root>/y1' incorporates:
   *  Inport: '<Root>/u1'
   *  Inport: '<Root>/u2'
   *  Sum: '<S1>/Sum'
   */
  rtY.y1 = u1 + u2;
}