
72
Interrupt Flags
The following flags are set on internal events (they activate an interrupt line when enabled).
They are cleared by writing a ‘ 1’ to the appropriate flag. Acknowledging the tx_msg interrupt
also acknowledges all tx_xmit interrupt sources. Acknowledging one of the tx_xmit interrupt
sources also acknowledges the tx_msg interrupt.
Note:
The reset value of this register’s bits is indeterminate.
Table 5-36. Interrupt Flags
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
OFFSET
46h
FIELD
RX_MSG
TX_MSG
TX_XMIT2
TX_XMIT1
TX_XMIT0
BUS_O
FF
CRC_ERR
FORM_ERR
ACK_ERR
STUF_ERR
BIT_ERR
RX_OVR
OVR_LOAD
ARB_LO
SS
///
RESET
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
R/W
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
Table 5-37. Interrupt Flag Definitions
Bits
Field Name
Description
15 RX_MSG
Rx Message
Depending on rx_level, at least one message is available.
14
TX_MSG
Tx Message
Depending on rx_level, at least one message is empty.
13 TX_XMIT2
Tx Xmit 2
Indicates that the message was successfully sent.
12
TX_XMIT1
Tx Xmit 1
Indicates that the message was successfully sent.
11 TX_XMIT0
Tx Xmit 0
Indicates that the message was successfully sent.
10
BUS_OFF
Bus Off State
CAN has reached the bus off state.
9 CRC_ERR
CRC Error
CRC error occurred while sending or receiving a message.
8
FORM_ERR
Format Error
Format error occurred while sending or receiving a
message.
7 ACK_ERR
Acknowledgement Error
Acknowledgement error occurred while sending or receiving
a message.
6
STUF_ERR
Stuffing Error
Stuffing error occurred while sending or receiving a
message.
5 BIT_ERR
Bit Error
Bit error occurred while sending or receiving a message.
4
RX_OVR
Receiver Overrun
A new message arrived while the receive buffer is full. This
Flag is set if either the incoming message overwrites an
existing one or is discarded.
3 OVR_LOAD
Overload Condition
An overload condition has occurred.
2
ARB_LOSS
Arbitration Loss
Arbitration was lost while sending a message.
1:0 ///
Reserved