Abstract: An apparatus for decoding a Manchester encoded waveform is described in wh a gating circuit responds to the mid-cell transitions in the encoded waveform to produce an enabling signal which causes a clock circuit to generate high frequency clock pulses. A programmable counter accumulates the generated clock pulses. If the counter exceeds a clock count threshold set by a multiposition switch before the beginning of the following enabling signal, it causes a storage element to sample the encoded waveform and store the sample to provide an output signal representing decoded data. A second, substantially equivalent circuit decodes timing from the encoded waveform. The multiposition switch provides the apparatus with the capability to decode encoded waveforms of varying frequency.

Abstract: High speed manchester encoding is provided by latching input data by means f a first clock pulse to provide a synchronized data source. This synchronized data is latched and inverted in a second latch circuit by a second clock pulse 180.degree. out of phase with the first clock pulse. The synchronized and inverted data is fed to a multiplexer where either data or data is selected depending on the state of the master clock applied to the select input of the multiplexer. The output from the multiplexer is the manchester encoded data stream.