Lossless CF FIR Filter

Cores are generated from Confluence; a modern logic design language. Confluence is a simple, yet highly expressive language that compiles into Verilog, VHDL, and C. See Confluent for more info. Finite impulse response (FIR) filters are common in DSP applications and consist of a delay bank (filter taps) and a sum-of-products.

Features

The filter architecture consists of a delay bank and a pipelined sum-of-products network. All arithmetics are lossless -- multipliers produce precision with the sum of the operands and each adder extends precision by 1 bit.

The filter has a synchronous reset to reinitialize the filter taps. The reset does not affect the pipeline registers in the sum-of-products network.

The filter includes ports for the filter coefficients; typically hardwired to constants.

Each file is stand-alone and represents a specific configuration.
The 3 configuration parameters are:
- Filter Order (# of delay taps)
- Input Precision
- Coefficient Precision

The configuration parameters are coded in the file names: cf_fir_3_16_8.v
- 3 : Filter order.
- 16 : Input precision.
- 8 : Coefficient precision.

Current configurations:
- cf_fir_3_8_8
- cf_fir_7_16_8
- cf_fir_7_16_16
- cf_fir_12_16_10
- cf_fir_16_16_16
- cf_fir_24_8_8
- cf_fir_24_16_16
- cf_fir_33_16_16