Setting FIR Length - 2023.2 English

Vitis Libraries

Release Date
2023.2 English

Minimum FIR length is set to 1.

Single Rate FIRs have no restriction placed on the FIR length selection.

However, rate-changing FIRs require each of the individual kernels to operate on a FIR length divisible by Decimation or Interpolation factor, imposing limits on the FIR length, e.g.: TP_FIR_LEN % TP_DECIMATE_FACTOR == 0 or TP_FIR_LEN % TP_INTERPOLATE_FACTOR == 0.

In SSR modes, see Super Sample Rate - Operation Modes, coefficients are distributed equally across all output paths. As a result, total number of FIRs coefficients must be divisible by number of paths, i.e. TP_FIR_LEN % (TP_SSR) == 0. For rate-changing FIRs this raises additional limits on the FIR length, where FIR length can be described by e.g.: TP_FIR_LEN % (TP_SSR * TP_PARA_INTERP_POLY * TP_PARA_DECI_POLY) == 0.


Invalid selection will report a message to the User in a form of Metadata error or a static_assert() with rule violation details and suggestion how to fix it.