Real-Time Workshop Embedded Coder

Sample Code Excerpts

In the model shown in Figure 4-1, block parameters and signals are associated with data objects belonging to each of the predefined custom storage classes, as follows:

• Parameters c, cv, and d reference Simulink.CustomParameter objects with custom storage class Const, ConstVolatile and Define, respectively.
• Signals v and intl reference Simulink.CustomSignal objects with custom storage class Volatile and Internal, respectively.
• Signals sw1 and sw2 reference Simulink.CustomSignal objects with custom storage class Struct, whose StructName storage class attribute is set to testpoints.
• Signals b1 and b2 reference Simulink.CustomSignal objects with custom storage class BitField, whose BitFieldName storage class attribute is set to signalBit.
• Parameter eg references a Simulink.CustomParameter object with custom storage class ExportToFile, whose FileName storage class attribute is set to exportedSignals.h.
• Parameter ig references a Simulink.CustomParameter object with custom storage class ImportFromFile, whose FileName storage class attribute is set to importedSignals.h, and whose IncludeDelimeter attribute is set to Braces.

Figure 4-1: Model Using Custom Storage Classes

The structure definitions for the bit field signalBit and the struct testpoints are in the generated file model_types.h, as shown in the following code excerpt. Notice also the inclusion of the generated file exportedSignals.h and the file importedSignals.h. The latter is assumed to be a hand-written file containing external signal definitions:

•   #include "exportedSignals.h"
    #include <importedSignals.h>
  
    typedef struct signalBit_tag {
      unsigned int b1:1;
      unsigned int b2:1;
    } signalBit_bitfield;
  
    /* Struct data */
    typedef struct testpoints_tag {
      real_T sw1;
      real_T sw2;
    } testpoints_struct;
  

A code excerpt from exportedSignals.h follows, declaring the parameter eg and making it visible to externally written code:

• #ifndef _exportedSignals_h
    #include "tmwtypes.h"
    extern real_T eg;
    #define _exportedSignals_h
  #endif
  

The following excerpt from the generated file model_data.c contains the storage declarations and initializers for the parameters c, cv, and d; signals v and intl; exported signal eg; signals b1 and b2 (embedded in signalBit); and sw1 and sw2 (embedded in testpoints):

• /* Data with custom storage class Const */
  const real_T c = 2.0;
  
  /* Data with custom storage class ConstVolatile */
  const volatile real_T cv = 4.0;
  
  /* Data with custom storage class Define */
  #define d                               5.0
  
  /* Data with custom storage class ExportToFile */
  real_T eg;
  
  /* Data with custom storage class Internal */
  real_T intl;
  
  /* Data with custom storage class Volatile */
  volatile real_T v;
  
  /* External Outputs Structure */
  ExternalOutputs rtY;
  
  /* user code (bottom of parameter file) */
  signalBit_bitfield signalBit = {0,0};
  testpoints_struct testpoints = {0.0,0.0};
  

The following code excerpt from model.c illustrates the application of these variables in the generated program:

•   /* Switch: '<Root>/Switch' incorporates:
     *   Inport: '<Root>/In1'
     *   Constant: '<Root>/Constant'
     *   Constant: '<Root>/Constant1'
     */
    if (signalBit.b1) {
      testpoints.sw1 = c;
    } else {
      testpoints.sw1 = cv;
    }
  
    /* Switch: '<Root>/Switch1' incorporates:
     *   Inport: '<Root>/In2'
     *   Constant: '<Root>/Constant2'
     *   Constant: '<Root>/Constant3'
     */
    if (signalBit.b2) {
      testpoints.sw2 = eg;
    } else {
      testpoints.sw2 = ig;
    }
  
    /* Sum: '<Root>/Sum' */
    v = testpoints.sw1 + testpoints.sw2;
  
    /* Gain: '<Root>/Gain'
     *
     * Regarding '<Root>/Gain':
     *   Gain value: d
     */
    intl = v * d;
  
    /* Outport: '<Root>/Out1' */
    rtY.Out1 = intl;
  

Ordering of Generated Storage Declarations

Requirements, Restrictions, Target Files