Serial I/O Filter

The Serial I/O Filter HSP43124 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.
For digital tuning applications, a separate multiplier is provided which allows the incoming data stream to be multiplied, or mixed, by a user supplied mix factor. A two pin Interface is provided for serially loading the mix factor from an external source or selecting the mix factor from an on-board ROM. The on-board ROM contains samples of a sinusoid capable of spectrally shifting the input data by one quarter of the sample rate, FS/4. This allows the chip to function as a digital Down Converter when the Filter stages are configured as a low-pass Filter
The serial Interface for 3- input and output data is compatible with the serial ports of common DSP Microprocessors Coefficients and configuration data are loaded over a bidirectional eight bit Interface
By Intersil Corporation