38.7.15 Interrupt

Note: Interrupt flags must be cleared and then read back to confirm the clear before exiting the ISR to avoid double interrupts.

The flags are set when one of the listed conditions is detected (edge-sensitive). A flag is cleared by writing a 1 to the corresponding bit field. Writing a 0 has no effect. A hard reset will clear the register.

Table 38-32. Register Bit Attribute Legend
Symbol	Description	Symbol	Description	Symbol	Description
R	Readable bit	HC	Cleared by Hardware	(Grey cell)	Unimplemented
W	Writable bit	HS	Set by Hardware	X	Bit is unknown at Reset
K	Write to clear	S	Software settable bit	—	—

Name:	IR
Offset:	0x50
Reset:	0x00000000
Property:	-


Bit	31	30	29	28	27	26	25	24
			ARA	PED	PEA	WDI	BO	EW
Access			R/W	R/W	R/W	R/W	R/W	R/W
Reset			0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	EP	ELO			DRX	TOO	MRAF	TSW
Access	R/W	R/W			R/W	R/W	R/W	R/W
Reset	0	0			0	0	0	0


Bit	15	14	13	12	11	10	9	8
	TEFL	TEFF	TEFW	TEFN	TFE	TCF	TC	HPM
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	RF1L	RF1F	RF1W	RF1N	RF0L	RF0F	RF0W	RF0N
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bit 29 – ARA Access to Reserved Address

Value	Description
0	No access to reserved address occurred.
1	Access to reserved address occurred.

Bit 28 – PED Protocol Error in Data Phase

Value	Description
0	No protocol error in data phase detected.
1	Protocol error in data phase detected (i.e., PSR.DLEC bits ( PSR<10:8>) != 0 and PSR.DLEC bits ( PSR<10:8>) != 0 ).

Bit 27 – PEA Protocol Error in Arbitration Phase

Value	Description
0	No protocol error in arbitration phase detected.
1	Protocol error in arbitration phase detected (i.e., PSR.LEC bits ( PSR<2:0>) != 0 and PSR.LEC bits ( PSR<2:0>) != 0 ).

Bit 26 – WDI Watchdog Interrupt

Value	Description
0	No Message RAM Watchdog event occurred.
1	Message RAM Watchdog event due to missing READY.

Bit 25 – BO 'bus off' Status

Value	Description
0	'bus off' status unchanged.
1	'bus off' status changed.

Bit 24 – EW Error Warning Status

Value	Description
0	Error Warning status unchanged.
1	Error Warning status changed.

Bit 23 – EP Error Passive

Value	Description
0	Error Passive status unchanged.
1	Error Passive status changed.

Bit 22 – ELO Error Logging Overflow

Value	Description
0	CAN Error Logging Counter did not overflow.
1	Overflow of CAN Error Logging Counter occurred.

Bit 19 – DRX Message stored in a Dedicated Rx Buffer

The flag is set whenever a received message has been stored into a dedicated Rx Buffer.

Value	Description
0	No Rx Buffer updated.
1	At least one received message stored into a Rx Buffer.

Bit 18 – TOO Timeout Occurred

Value	Description
0	No timeout.
1	Timeout reached.

Bit 17 – MRAF Message RAM Access Failure

The flag is set, when the Rx Handler:

has not completed acceptance filtering or storage of an accepted message until the arbitration field of the following message has been received. In this case acceptance filtering or message storage is aborted and the Rx Handler starts processing of the following message.
was not able to write a message to the Message RAM. In this case message storage is aborted.

In both cases the FIFO put index is not updated. The New Data flag for a dedicated Rx Buffer is not set, a partly stored message is overwritten when the next message is stored to this location.

The flag is also set when the Tx Handler was not able to read a message from the Message RAM in time. In this case message transmission is aborted. In case of a Tx Handler access failure the CAN is switched into Restricted Operation Mode. To leave Restricted Operation Mode, the Host CPU must clear CCCR.ASM bit (CCCR <2>).

Value	Description
0	No Message RAM access failure occurred.
1	Message RAM access failure occurred.

Bit 16 – TSW Timestamp Wraparound

Value	Description
0	No timestamp counter wrap-around.
1	Timestamp counter wrapped around.

Bit 15 – TEFL Tx Event FIFO Element Lost

Value	Description
0	No Tx Event FIFO element lost.
1	Tx Event FIFO element lost, also set after write attempt to Tx Event FIFO of size zero.

Bit 14 – TEFF Tx Event FIFO Full

Value	Description
0	Tx Event FIFO not full.
1	Tx Event FIFO full.

Bit 13 – TEFW Tx Event FIFO Watermark Reached

Value	Description
0	Tx Event FIFO fill level below watermark.
1	Tx Event FIFO fill level reached watermark.

Bit 12 – TEFN Tx Event FIFO New Entry

Value	Description
0	Tx Event FIFO unchanged.
1	Tx Handler wrote Tx Event FIFO element.

Bit 11 – TFE Tx FIFO Empty

Value	Description
0	Tx FIFO not-empty.
1	Tx FIFO empty.

Bit 10 – TCF Transmission Cancellation Finished

Value	Description
0	Transmission cancellation not finished.
1	Transmission cancellation finished.

Bit 9 – TC Timestamp Completed

Value	Description
0	No transmission completed.
1	Transmission completed.

Bit 8 – HPM High Priority Message

Value	Description
0	No high priority message received.
1	High priority message received.

Bit 7 – RF1L Rx FIFO 1 Message Lost

Value	Description
0	No Rx FIFO 1 message lost.
1	Rx FIFO 1 message lost. also set after write attempt to Rx FIFO 1 of size zero.

Bit 6 – RF1F Rx FIFO 1 Full

Value	Description
0	Rx FIFO 1 not full.
1	Rx FIFO 1 full.

Bit 5 – RF1W Rx FIFO 1 Watermark Reached

Value	Description
0	Rx FIFO 1 fill level below watermark.
1	Rx FIFO 1 fill level reached watermark.

Bit 4 – RF1N Rx FIFO 1 New Message

Value	Description
0	No new message written to Rx FIFO 1.
1	New message written to Rx FIFO 1.

Bit 3 – RF0L Rx FIFO 0 Message Lost

Value	Description
0	No Rx FIFO 0 message lost.
1	Rx FIFO 0 message lost. also set after write attempt to Rx FIFO 0 of size zero.

Bit 2 – RF0F Rx FIFO 0 Full

Value	Description
0	Rx FIFO 0 not full.
1	Rx FIFO 0 full.

Bit 1 – RF0W Rx FIFO 0 Watermark Reached

Value	Description
0	Rx FIFO 0 fill level below watermark.
1	Rx FIFO 0 fill level reached watermark.

Bit 0 – RF0N Rx FIFO 0 New Message

Value	Description
0	No new message written to Rx FIFO 0.
1	New message written to Rx FIFO 0.