Performance of C-BUS Communication in CMX7032 IC with SPI Communication in ATxmega128A1 IC

Automatic Identification System (AIS) system, that is equipped with transceiver device, works by continuously broadcasting status and position information of host vessel that enables other similar equipped vessels in the surrounding area to receive, decode, then display the information to provide maritime traffic information. One of AIS data processor IC that can be used in AIS transceiver device is CMX7032. For communicating with other IC, CMX7032 provides C-BUS interface feature that is compatible with SPI interface. ATxmega128A1, that has SPI feature and its operating voltage requirement is compatible with CMX7032, can be used to load and activate Function ImageTM (FI) via C-BUS – SPI communication into CMX7032 so it can work properly. Method used to observe C-BUS – SPI communication performance is literature review and observation using various CMX7032 and ATxmega128A1 main clock frequency and C-BUS – SPI clock frequency. Observation results show that right checksum values and increased CMX7032 power consumption are successful FI loading indicators, while increased ATxmega128A1 power consumption exceeding in successful FI loading and activating case is unsuccessful FI activating indicator. Higher CMX7032 main clock frequency demands higher C-BUS – SPI clock frequency to support successful FI loading and activating process. Observation results also show that using same ATxmega128A1 main clock frequency, higher C-BUS – SPI clock frequency results less required time for loading and activating FI. Then, when using same C-BUS – SPI clock frequency, different CMX7032 main clock frequency does not affect significantly to the time required for loading and activating FI.