The HSP43216 Halfband Filter addresses a wide variety of applications by combining fS/4 (fS= sample frequency) quadrature up/down convert circuitry with a fixed coefficient halfband filter processor as shown in the block diagram. These elements may be configured to operate in one of the four following modes: decimate by 2 filtering of a real input signal; interpolate by 2 filtering of a real input signal; fS/4 quadrature down conversion of a real input signal followed by decimate-by-2 filtering to produce a complex analytic signal; interpolate-by-2 filtering of a complex analytic signal followed by fS/4 quadrature up conversion to produce a real valued output. The frequency response of the HSP43216's halfband filter has a shape factor, (passband+transition band)/passband, of 1. 24:1 with 90dB of stopband attenuation. The passband has less than 0. 0003dB of ripple from 0fS to 0. 2fSwith stopband attenuation of greater than 90dB from 0. 3fSto Nyquist. At 0. 25fSthe filter provides 6dB of attenuation. The HSP43216 processes data streams with word widths up to 16-bits and data rates up to 52MSPS. The processing throughput of the part is easily doubled to rates of up to 104MSPS by using the part together with an external multiplexer or demultiplexer. Programmable rounding is provided to support output precisions from 8-bits to 16-bits.