This example shows how to use referenced data dictionaries to store multiple sets of data types for a model. This example also shows how to change the data types by switching the referenced data dictionary.
Open the folder containing the example. At the MATLAB® command line, enter:
cd(fullfile(docroot,'toolbox','fixpoint','examples'))
Copy these files to a local writable folder:
ex_data_dictionary.slx
— Simulink® model
using a data dictionary to store its data types
mdl_dd.sldd
— Main data
dictionary
flt_dd.sldd
— Referenced
data dictionary using floating-point data types
fix_dd.sldd
— Referenced
data dictionary using fixed-point data types
In the folder you copied the files to, open the ex_data_dictionary
model.
ex_data_dictionary
In the lower left corner of the Simulink Editor,
click to open the dictionary.
The data dictionary defines the parameters of the Gain blocks
in the F1
and F2
subsystems. mdl_dd
is
associated with a referenced data dictionary, flt_dd
,
which defines the output data types of the gain blocks in the model’s
subsystems.
In the Model Explorer, in the Contents pane, the Data Source column shows the source data dictionary for each Gain block parameter.
Return to the model. Open the F1
subsystem
and double-click the a1
block. The block gain is
specified as f1_a1_param
, which is defined in the
data dictionary.
In the Signal Attributes tab, the block
output data type is specified as f1_a1_dt
. The
data type of f1_a1_dt
is defined in the referenced
data dictionary, flt_dd
.
The fix_dd
data dictionary contains the same
entries as flt_dd
, but defines fixed-point data
types instead of floating-point data types. To use the fixed-point
data types without changing the model, replace flt_dd
with fix_dd
as
the referenced data dictionary of mdl_dd
.
In the Model Explorer, in the Model Hierarchy pane,
right-click mdl_dd
and select Properties
.
Remove the referenced floating-point data dictionary.
In the Data Dictionary dialog box, in the Referenced Dictionaries pane,
select flt_dd
and click Remove.
Add a reference to the fixed-point data dictionary. Click Add
Reference and select fix_dd
. Click OK to
close the dialog box.
In the Model Explorer, right-click mdl_dd
and
select Save Changes
.
Return to the Simulink editor and update the model.
The model now uses fixed-point data types.