Communication systems and communication methods

Abstract

To provide a communication system and a communication method that suppress the occurrence of mismatch between a state notified to an external apparatus that is a transmission source of serial data and a state of the communication system.SOLUTION: A counter 6 counts the number of pulses of a first clock signal CLK from starting reception of serial data SDA. A comparison circuit 7 outputs a result of comparison between the count value of the counter 6 and a predetermined value. When it is determined that the count value of the counter 6 is less than the predetermined value when the reception of the serial data SDA is finished based on the comparison result, a serial communication circuit 2 notifies an external apparatus that the serial data SDA could not be received.SELECTED DRAWING: Figure 1

Claims

1. A serial communication circuit that converts serial data transmitted from an external device into parallel data and outputs a reception completion signal indicating the end of reception of the serial data, An oscillator circuit that outputs a first clock signal, A synchronization circuit that synchronizes the reception completion signal with the first clock signal, The system includes a processing unit that operates in synchronization with the first clock signal and acquires the parallel data in response to the input of the reception end signal synchronized with the first clock signal. It is a communication system, A counter that counts the number of pulses of the first clock signal from the start of receiving the serial data until at least the end of receiving the serial data, The system includes a comparison circuit that outputs the result of comparing the count value of the counter with a predetermined value, When the serial communication circuit finishes receiving the serial data, if the comparison result indicates that the counter's count value is less than the predetermined value, it notifies the external device that it was unable to receive the serial data. Communication system.

2. In the communication system described in claim 1, The serial communication circuit receives a second clock signal with a lower frequency than the first clock signal transmitted from the external device, and outputs a reception completion signal synchronized with the second clock signal. Communication system.

3. The serial communication circuit converts serial data transmitted from an external device into parallel data and outputs a reception completion signal indicating the end of reception of the serial data. The synchronization circuit synchronizes the reception completion signal with the first clock signal. The processing unit operates in synchronization with the first clock signal and acquires the parallel data in response to the input of the reception end signal which is synchronized with the first clock signal. A method of communication, If the serial communication circuit counts the number of pulses of the first clock signal, which is counted between the start and end of reception of the serial data, and the count value of the number of pulses of the first clock signal is less than a predetermined value, it notifies the external device that it was unable to receive the serial data. Communication method.

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