7.4.20. Variable-Rate CIC Filter
You can control the rate change with a register field, which is part of the control interface. The register field controls the generation of a valid signal that feeds into the differentiators.
The design example also contains a gain compensation block that compensates for the rate change dependent gain of the CIC. It shifts the input up so that the MSB at the output is always at the same position, regardless of the rate change that you select.
The associated setup file contains parameters for the minimum and maximum decimation rate, and calculates the required internal data widths and the scaling number. To change the decimation factor for simulation, adjust variable CicDecRate to the desired current decimation rate.
The model file is demo_vcic.mdl.