User`s guide

5 Exporting F ilter Coefficients from FDATool
If you set custom word and fraction lengths to represent your filter coefficients,
theexportprocesssuggestsadatatypetomaintainthebestfidelity for the
filter.
The export process converts your custom word and fraction lengths to a
suggested export data type, using the fo llow ing rules:
• Round the word length up to the nearest larger supported data type. For
example, round an 18-bit word length up to 32 bits.
• Set the fraction length to the maintain the same difference between the
word and fraction length in the new datatypeasappliesinthecustom
data type.
For example, if y ou specify a fixed-point data type with word length of
14 bits and fraction length of 11 bits, the export process suggests an
integer data type with word length of 16 b its and fraction length of 13
bits, retaining the 3 bit difference.
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