Multiple Coefficient Sets - 7.2 English

FIR Compiler (PG149)

Document ID
PG149
Release Date
2022-10-26
Version
7.2 English

For multiple coefficient filters, a single .coe file is used to specify the coefficient sets. Each coefficient set should be appended to the previous set of coefficients.

For example, if a 2-coefficient set, 10-tap symmetric filter was being designed and coefficient set #0 was: coef data = -1, -2, -3, 4, 5, 5, 4, -3, -2, -1;

and coefficient set #1 was:

coefdata = -9, -10, -11, 12, 13, 13, 12, -11, -10, -9;

then the .coe file for the entire filter would be:

radix = 10;

coefdata = -1, -2, -3, 4, 5, 5, 4, -3, -2, -1, -9, -10, -11, 12, 13, 13, 12, -11, -10, -9;

All coefficients sets in a multiple set implementation must exhibit the same symmetry. For example, if even one set of a multi-set has non-symmetric coefficient structure, then all sets are implemented using that structure. All coefficient sets must also be of the same vector length. If one coefficient set has fewer coefficients, it must be zero padded – either appended with zeros when non-symmetric or prepended and appended with an equal number of zeros when symmetric. See the Coefficient Padding section for further information.