Starting Filter Design HDL Coder
Opening the Filter Design HDL Coder UI from Filter Designer
To open the initial Generate HDL dialog box from Filter Designer, do the following:
filterDesignercommand at the MATLAB® command prompt. The Filter Designer displays its initial dialog box.
If the filter design is quantized, skip to step 3. Otherwise, quantize the filter by clicking the Set Quantization Parameters button. The Filter arithmetic menu appears in the bottom half of the dialog box.
Supported filter structures allow both fixed-point and floating-point (double) realizations.
If desired, adjust the setting of the Filter arithmetic option. The Filter Designer displays the first of three tabbed panes of its dialog box.
Select Targets > Generate HDL. The Filter Designer displays the Generate HDL dialog box.
If the coder does not support the structure of the current filter in the Filter Designer, an error message appears.
Opening the Filter Design HDL Coder UI from the Filter Builder
If you are not familiar with the Filter Builder UI, see the DSP System Toolbox™ documentation.
To open the initial Generate HDL dialog box from Filter Builder, do the following:
At the MATLAB command prompt, type a
filterBuildercommand that corresponds to the filter response or filter object you want to design.
The following figure shows the default settings of the main pane of the Filter Builder Lowpass Design dialog box.
Set the filter design parameters as required.
Optionally, select the check box Use a System object to implement filter.
Click the Data Types tab. Set Arithmetic to
Fixed pointand select data types for internal calculations.
Click the Code Generation tab.
In the Code Generation pane, click the Generate HDL button. This button opens the Generate HDL dialog box, passing in the current filter object from Filter Builder.
Set the desired code generation and test bench options and generate code in the Generate HDL dialog box.
Opening the Filter Design HDL Coder UI Using the
You can use the
fdhdltool command to open
the Generate HDL dialog box directly from the MATLAB command
line. The syntax is:
Hd is a type of filter object that
is supported for HDL code generation. If the filter is a System object™,
you must specify the input data type.
fdhdltool function is particularly useful when you must use the
Filter Design HDL Coder™ UI to generate HDL code for filter structures that are not supported
by Filter Designer or Filter Builder. For example, the following commands create a
Farrow fractional delay filter object
farrowfilt, which is passed
in to the
farrowfilt = dsp.VariableFractionalDelay('InterpolationMethod','Farrow'); inputDataType = numerictype(1,18,17); fdDataType = numerictype(1,8,7); fdhdltool(farrowfilt,inputDataType,fdDataType);
fdhdltool operates on a copy of the filter
object, rather than the original object in the MATLAB workspace.
Changes made to the original filter object after invoking
not apply to the copy and do not update the Generate HDL dialog box.
The name of the copied filter object by default is
This is reflected in the filter Name field. Likewise,
the test bench file name is
is reflected in the File name field on the Test
Bench pane. Update these default values to user-defined
names if required.