SCRAMBLE CIRCUIT OF SATELLITE RECEIVER

摘要

In the satellite broadcasting receiver for intercepting and decoding PCM audio frame data, the logical state of charged flags included in the data of each channel, is detected. The chaged flags detected at a corresp. channel period are stored. Then the charged flags of a previous frame are simultaneously gated at the start timing of one frame. The clocks of a frame period are counted and a multiframe signal of a given frame period is generated. The logical values of the charged flags gated with the frame period are accumulated, and an audio mute signal is generated when the charged flags over a given number are detected during a multiframe signal period.