Filter Design HDL Coder™

CastBeforeSum

Enable or disable type casting of input values for addition and subtraction operations

Settings

'off' (default)

Preserve the types of input values during addition and subtraction operations and then convert the result to the result type.

'on'

Type cast input values in addition and subtraction operations to the result type before operating on the values. This setting produces numeric results that are typical of DSP processors.

The CastBeforeSum property is related to the FDATool setting for the quantization property Cast signals before accum. as follows:

Some filter object types do not have theCast signals before accum. property. For such filter objects, CastBeforeSum is effectively off when HDL code is generated; it is not relevant to the filter.
Where the filter object. does have the Cast signals before accum. property, the coder by default sets CastBeforeSum following the setting of Cast signals before accum. in the filter object. This is visible in the GUI. If the you change the setting of Cast signals before accum., the coder updates the setting of Cast before sum.
However, by explicitly setting the CastBeforeSum property, you can override the Cast signals before accum. setting passed in from FDATool.

CastBeforeSum

Settings

See Also