摘要 |
A communication apparatus (400) capable of supporting two bidirectional communication protocols is connected to a single bidirectional signal line and a controller (414). Software processes of the controller (414) include only processes of requesting transmission, setting transmission data, and decoding reception data. All communication processes, such as generation of a waveform during transmission, sampling of data during reception, decoding of a reception address, and the like, are hardware processes of the communication apparatus (400). In accordance with a control of a state determining circuit (405), the generation of a waveform during transmission is controlled by a transmission control circuit (409) and a data output circuit (111), while the sampling of data during reception and the decoding of a reception address are controlled by a waveform timing check circuit (407) and a reception control circuit (410). A transmission waveform can be arbitrarily set from the controller (414), and transmission/reception timing and an operation of a forced LOW transmission control circuit (208) can be selectively performed by a hardware process or a software process.
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