摘要 |
In a system having a frequency encoded data stream and a source of clock signals phase locked to the data stream, for subsequent demodulation of the data stream, the clock source is at a frequency that is a multiple of the nominal frequency for demodulating, and a counter is employed to divide the clock. The counter is controlled by the output of a phase comparator, to control the addition to and inhibiting of counting of the counter. The control circuit controls the counter in a non-linear relationship with respect to the phase error, and has a memory function for storing previous states of the counter, to permit repetitive correction for small errors in the same manner. The phase comparator and control are preferably a programmed logic array.
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