The Serial I/O Filter is a high performance filter engine that is ideal for off loading the burden of filter processing from a DSP microprocessor. It supports a variety of multistage filter configurations based on a user programmable filter and fixed coefficient halfband filters. These configurations include a programmable FIR filter of up to 256 taps, a cascade of from one to five halfband filters, or a cascade of halfband filters followed by a programmable FIR. The half band filters each decimate by a factor of two, and the FIR filter decimates from one to eight. When all six filters are selected, a maximum decimation of 256 is provided.

FEATUREs
• 45MHz Clock Rate
• 256 Tap Programmable FIR Filter
• 24-Bit Data, 32-Bit Coefficients
• Cascade of up to 5 Half Band Filters
• Decimation from 1 to 256
• Two Pin Interface for Down Conversion by FS/4
• Multiplier for Mixing or Scaling Input with an External Source
• Serial I/O Compatible with Most DSP Microprocessors

APPLICATIONs
• Low Cost FIR Filter
• Filter Co-Processor
• Digital Tuner