Distributed Arithmetic FIR (DA-FIR) Filter Generator
Overview
The Lattice Distributed Arithmetic Finite Impulse Response (DA-FIR) Filter Generator IP implements a highly configurable, multi-channel DA-FIR filter, using distributed arithmetic algorithms implemented in FPGA Look Up Table (LUT) or Embedded Block Memory (EBR) to efficiently support the sum-of-product calculations required to perform the filter function. These techniques generate very area-efficient utilization of the FPGA LUTs while enabling savings of multiply-accumulate blocks (sysDSP) for other design logic. As a result, the DA-FIR Filter Generator IP core is extremely useful for implementing custom DSP blocks in Lattice FPGAs. Please refer to the user's guide to determine which cores are available for each device family.
Key Features
- Variable number of taps up to 1024
- Multi-channel support (up to 32 channels)
- Polyphase interpolation/decimation filters
- Halfband filters
- Interpolation and Decimation ratios from 2 to 32
- Input data widths from 4 to 32 bits
- Coefficient widths from 4 to 32 bits
- Signed or unsigned data and coefficients
- Selectable rounding: truncation, rounding away from zero, convergent rounding
- Optional saturation logic for overflow handling
- Full precision arithmetic
- Specification of fractional inputs and outputs
- Support for both serial and parallel filters, with user specified degree of parallelism.
- Configurable pipelining to increase performance
- Optimizations based on filter characteristics (symmetry and halfband).
- Handshake signals to facilitate smooth interfacing
Block Diagram
