Return From Bus Off Function; Time Stamp Counter And Time Stamp Function; Listen-Only Mode - Renesas M16C/60 Series Hardware Manual

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M16C/6N5 Group

Return from Bus off Function

When the protocol controller enters bus off state, it is possible to make it forced return from bus off state by
the return from bus off function of the C0CTLR register. At this time, the error state changes from bus off
state to error active state. Implementation of this function initializes the protocol controller. However, registers
of the CAN module such as C0CONR register and the content of each slot are not initialized.

Time Stamp Counter and Time Stamp Function

When the C0TSR register is read, the value of the time stamp counter at the moment is read. The period of
the time stamp counter reference clock is the same as that of 1 bit time that is configured by the C0CONR
register. The time stamp counter functions as a free run counter.
The 1 bit time period can be divided by 1 (undivided), 2, 4 or 8 to produce the time stamp counter reference
clock. Use the TSPreScale bits 1 and 0 of the C0CTLR register to select the divide-by-n value.
The time stamp counter is equipped with a register that captures the counter value when the protocol
controller regards it as a successful reception. The captured value is stored when a time stamp value is
stored in a reception slot.

Listen-Only Mode

When the RXOnly bit of the C0CTLR register is set to "1", the module enters listen-only mode.
In listen-only mode, no transmission -- data frames, error frames, and ACK response -- is performed to bus.
Rev.1.00 2003.05.30 page 223
CAN Module