This example shows how to specify known data types for block parameters within your system. Load the system for which you want to optimize the data types.

load_system('ex_auto_gain_controller');

To specify that the input to the system you are converting will always be an eight-bit integer, create a BlockParameter object that specifies the block parameter, and the data type.

bp = Simulink.Simulation.BlockParameter(...
'ex_auto_gain_controller/input_signal', 'OutDataTypeStr', 'int8');

The fxpOptimizationOptions object, opt, specifies options to use during data type optimization. To specify the data type of the input to the system, use the addSpecification method.

opt = fxpOptimizationOptions;
addSpecification(opt, 'BlockParameter', bp)

You can view all specifications added to a fxpOptimizationOptions object using the showSpecifications method.

showSpecifications(opt)

    Index         Name                      BlockPath                  Value 
    _____    ______________    ____________________________________    ______

      1      OutDataTypeStr    ex_auto_gain_controller/input_signal    'int8'

ans=1×4 table
    Index         Name                      BlockPath                  Value 
    _____    ______________    ____________________________________    ______

      1      OutDataTypeStr    ex_auto_gain_controller/input_signal    'int8'