Rainbow Electronics CAN интерфейс - Manual (Page 43)

BOSCH
ROBERT BOSCH GmbH, Postfach 300240, D-7000 Stuttgart 30
Sep. 1991
Part B - page 41
without any internal activity and with disconnected bus drivers. The sleep mode is
finished with a wake-up by any bus activity or by internal conditions of the system. On
wake-up, the internal activity is restarted, although the MAC sublayer will be waiting for
the system’s oscillator to stabilize and it will then wait until it has synchronized itself to
the bus activity (by checking for eleven consecutive ’recessive’ bits), before the bus
drivers are set to "on-bus" again.
Oscillator Tolerance
The Bit Timing requirements allow ceramic resonators to be used in applications with
transmission rates of up to 125kbit/s as a rule of thumb; for a more precise evaluation
refer to
Dias, S; Chapman, M;
“Impact of Bit Representation on Transport Capacity and Clock
Accuracy in Serial Data Streams”,
SAE Technical Paper Series 890532, Multiplexing in Automobiles SP-773
March 1989
For the full bus speed range of the CAN protocol, a quartz oscillator is required.
Basic Concepts