This paper describes two different methods to detect the CAN baudrate with Infineon CAN devices. These methods allow non-initialized CAN nodes to connect to a running CAN system, although the current baudrate is not known. Hereby the running CAN system is not disturbed.
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Detection with CAN Analyzing modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Measurements of dominant CAN bits via a Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1 CAN Baudrate Detection with C16xC Microcontrollers . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.2 Measurement of dominant CAN bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.3 CAN Bit Time Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2.4 Program Code: baudrate detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2.4.1 Baudrate Detection Routine “bauddet.c” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2.4.2 Dominant bit measurement “measure.c” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10