Decoder for decoding PWM code and communications system

摘要

A decoder for decoding an input signal coded with a pulse width modulation code as a line code to an output signal in a binary code, has a first memory, a first timer, a determination circuit and a first controller. The information on a duty duration of the PWM code, corresponding to at least one kind of the output signals, is stored on the first memory. The first timer has a capacity to measure the duty duration of the input signal. The determination circuit has a capacity to determining which kind of the output signals corresponds to the input signal, on the basis of the information stored on the first memory and the duty duration measured with the first timer. The first controller has a capacity to updating the information stored on the first memory, on the basis of the determination result and the measured duty duration.

主权项

1. A decoder for decoding an input signal coded with a pulse width modulation (PWM) code as a line code to an output signal in a binary code, the input signal in a transmission line being outputted from a clock master or a normal node communicating with each other via the transmission line, the decoder comprising:
a first memory on which information on a duty duration of the PWM code is stored, a first signal and a second signal in the PWM code being assigned with the respective signals in the binary code depending on their duty ratio, the duty ratio being the ratio of the duty duration to a pulse period, the first signal being supplied from the clock master, the second signal being generated by changing the supplied first signal by the normal node, the information on the duty duration of the first signal being stored on the first memory; a first timer that measures the duty duration of the input signal; a determination circuit that determines which output signals corresponds to the input signal, on the basis of the information stored on the first memory and the duty duration measured with the first timer; a first controller that updates the information stored on the first memory, on the basis of the determination result and the measured duty duration.