MATLAB: Does the QPROD function override QMULT and truncate the multiplicand in the Filter Design Toolbox

designfilterFilter Design Toolboxfixed-pointfixedpointmultiplicandmultiplyoverflowproductqfiltqmultqprodquantizedsaturatetoolboxwarning

I would like to know if the QPROD function overrides QMULT and truncate the multiplicand in the Filter Design Toolbox.

Best Answer

This is a bug with the QFILT/FILTER function that has been fixed in Filter Design 2.2 (R13).

If you are using a earlier version, there are no workarounds.

Related Solutions

MATLAB: How to obtain the quantized filter coefficients as fixed-point objects in Filter Design Toolbox 4.0 (R2006b)

The ability to obtain the quantized filter coefficients as fixed-point objects is not available in the Filter Design Toolbox 4.0 (R2006b).

To work around this you can manually convert the coefficients to fixed-point objects as shown below:

d=fdesign.lowpass(0.40,0.54,0.05,50);
hd=design(d,'kaiserwin','filterstructure','dffir');
hd.Arithmetic='fixed';
set(hd,'filterInternals','specifyprecision');
hd.productWordLength = 16;
hd.accumwordLength = 40;
myfi = fimath('maxproductwordlength',16,'maxsumwordlength',40);
numerator = fi(hd.numerator,hd.signed,hd.inputwordlength,...
          hd.inputfracLength, 'fimath', myfi)

MATLAB: Override Unit Delay block outptut

No, you can't. set_param() is used to change the "Parameters" of the model or block. It can not be used to change the dynamic output of a block.

What you want to do sounds like fault injection for debugging purpose. It's like cut a line on a circuit board and feed a different signal temporarily. I am afraid you can't use set_param() for that.

You might have to put this fault injection capability into your design. In your Stateflow chart, define a condition and a third variable. Use this condition and variable to "cut the line".

If ConditionIsTrue
op=ThirdVariable;
else
op=in+constant;
end

Best Answer

Related Solutions

MATLAB: How to obtain the quantized filter coefficients as fixed-point objects in Filter Design Toolbox 4.0 (R2006b)

MATLAB: Override Unit Delay block outptut

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