Method of initializing a control unit connected to a diagnostic bus

Abstract

A method of initializing a control unit connected to a diagnostic bus by a trigger word using signals on the diagnostic bus over the RXD line of a microcontroller having a port register and a receive buffer register. According to this method, information is sampled from the port register for the low/high logic state with a predetermined sampling cycle to detect the trigger word, and a readout of the receive buffer register and an analysis of the status information are performed. To prevent unintentional initialization or triggering of the control unit, a check at the sampling time during input of the trigger word is performed to determine whether the receive buffer register is full or whether there is a transition from the high logic signal level to the low logic signal level on the K line of the diagnostic bus, in which case a trigger word causes a framing error in this test. Further, an initialization of the control unit is accepted if there is a framing error; otherwise, the initialization is discarded and another transition from, for example, a high logic signal level to a low logic signal level is waited for.

Dependencies are inferred from the claim text.