Programming The Bit Timing 0 (Can_Btime0) Register - Intel 8XC196K Series User Manual

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12.4.2 Programming the Bit Timing 0 (CAN_BTIME0) Register

Bit timing register 0 (Figure 12-7) defines the length of one time quantum and the maximum

amount by which the sample point can be moved (t

lengthened) to compensate for resynchronization.

Program the CAN bit timing 0 (CAN_BTIME0) register to define the length of one time quantum and

the maximum number of time quanta by which a bit time can be modified for resynchronization.

The CCE bit (CAN_CON.6) must be set to enable write access to this register.

Figure 12-7. CAN Bit Timing 0 (CAN_BTIME0) Register

CAN SERIAL COMMUNICATIONS CONTROLLER

Synchronization Jump Width

This field defines the maximum number of time quanta by which a resyn-

chronization can modify t

3. The hardware adds 1 to the programmed value, so a "1" value causes

the CAN peripheral to add or subtract 2 time quanta, for example. This

adjustment has no effect on the total bit time; if t

is decreased by 2 tq, and vice versa.

Baud-rate Prescaler

This field defines the length of one time quantum (tq), using the following

formula, where t

is the input clock period on XTAL1. Valid programmed

values are 0–63.

For example, at 20 MHz operation, the system clock period is 50 ns.

Writing 3 to BRP achieves a time quanta of 400 ns; writing 1 to BRP

achieves a time quanta of 200 ns.

can be shortened and the other

Reset State:

. Valid programmed values are 0–

is increased by 2 tq,