I set the Bit Rate of CAN to be 1000K ,what does the Calculated Bit Rate mean ,why it is 925.926K ?
SP is a sampling point. Briefly, it defines a point where the bit value shall be sampled, usually it lies between 70 and 85 %. The propagation delay is a time between an edge generation on a transmitter and it's detection on a receiver. It defines the minimum value of propagation segment of transmitted/received bits. The value of propagation delay depends on the length of the CAN bus cable, the higher bit rates you want, the shorter cable should be used (recommended values can be found easily, e.g. the cable should be no longer than 40 meters for 1 Mbit/s).
Detailed description of CAN bus timing can be found on Bosch Semiconductors' site: The Configuration of the CAN Bit Timing.
Why the Calculated Bit Rate isn't exactly 1000 kbit/s? It depends besides other things on clock frequency. On our systems looks like this:
