Apc and acc processing using common circuitry

Abstract

Chrominance signals of a digitized composite video signal are processed by including automatic phase control and automatic chroma control operations that use circuit elements that are concurrently available for both operations as well as for other signal processing operations. The automatic phase control operation calculates a phase error corresponding to a phase difference between a reference clock signal and a burst synchronization signal of the chrominance signal. The reference clock signal is generated in response to the phase error data, such that the phase error is minimized and the reference clock signal coincides with the burst synchronization signal. The automatic chroma control operation multiplies the chrominance signal by coefficient data corresponding to the difference between the chrominance signal and a reference value to generate a constant level chrominance signal.