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Programmer’s Model of Control Registers
M68HC12B Family Data Sheet, Rev. 9.1
Freescale Semiconductor
267
RERRIF — Receiver Error Passive Interrupt Flag
This flag is set when the msCAN12 goes into error passive status due to the receive error counter
(REC) exceeding 127 and the bus-off interrupt flag is not set
(1)
. If not masked, an error interrupt is
pending while this flag is set.
0 = No receiver error passive status has been reached.
1 = msCAN12 went into receiver error passive status.
TERRIF — Transmitter Error Passive Interrupt Flag
This flag is set when the msCAN12 goes into error passive status due to the transmit error counter
(TEC) exceeding 127 and the bus-off interrupt flag is not set
(2)
. If not masked, an error interrupt is
pending while this flag is set.
0 = No transmitter error passive status has been reached.
1 = msCAN12 went into transmitter error passive status.
BOFFIF — Bus-Off Interrupt Flag
This flag is set when the msCAN12 goes into bus-off status, due to the transmit error counter
exceeding 255. It cannot be cleared before the msCAN12 has monitored 128 times 11 consecutive
recessive bits on the bus. If not masked, an error interrupt is pending while this flag is set.
0 = No bus-off status has been reached.
1 = msCAN12 went into bus-off status.
OVRIF — Overrun Interrupt Flag
This flag is set when a data overrun condition occurs. If not masked, an Error interrupt is pending while
this flag is set.
0 = No data overrun has occurred.
1 = A data overrun has been detected.
RXF — Receive Buffer Full Flag
The RXF flag is set by the msCAN12 when a new message is available in the foreground receive
buffer. This flag indicates whether the buffer is loaded with a correctly received message. After the
CPU has read that message from the receive buffer, the RXF flag must be handshaken (cleared) to
release the buffer. A set RXF flag prohibits the exchange of the background receive buffer into the
foreground buffer. If not masked, a receive interrupt is pending while this flag is set.
0 = Receive buffer is released (not full).
1 = Receive buffer is full. A new message is available.
NOTE
To ensure data integrity, no registers of the receive buffer shall be read
while the RXF flag is cleared.The CRFLG register is held in the reset state
when the SFTRES bit in CMCR0 is set.
1. Condition to set the flag: RERRIF = (128
≤
REC
≤
255) & BOFFIF
2. Condition to set the flag: TERRIF = (128
≤
TEC
≤
255) & BOFFIF