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CAN Registers
807
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
Controller Area Network (CAN) Module
11.4.2 CANSTS Register (Offset = 0x4) [reset = 0x0]
CAN Status (CANSTS)
The status register contains information for interrupt servicing such as Bus-Off, error count threshold, and
error types.
The LEC field holds the code that indicates the type of the last error to occur on the CAN bus. This field is
cleared when a message has been transferred (reception or transmission) without error. The unused error
code 0x7 may be written by the CPU to manually set this field to an invalid error so that it can be checked
for a change later.
An error interrupt is generated by the BOFF and EWARN bits, and a status interrupt is generated by the
RXOK, TXOK, and LEC bits, if the corresponding enable bits in the CAN Control (CANCTL) register are
set. A change of the EPASS bit or a write to the RXOK, TXOK, or LEC bits does not generate an interrupt.
Reading the CAN Status (CANSTS) register clears the CAN Interrupt (CANINT) register, if it is pending.
CANSTS is shown in
and described in
.
Return to
Figure 11-6. CANSTS Register
31
30
29
28
27
26
25
24
RESERVED
R-0x0
23
22
21
20
19
18
17
16
RESERVED
R-0x0
15
14
13
12
11
10
9
8
RESERVED
R-0x0
7
6
5
4
3
2
1
0
BOFF
EWARN
EPASS
RXOK
TXOK
LEC
R-0x0
R-0x0
R-0x0
R/W-0x0
R/W-0x0
R/W-0x0
Table 11-9. CANSTS Register Field Descriptions
Bit
Field
Type
Reset
Description
31-8
RESERVED
R
0x0
7
BOFF
R
0x0
Bus-Off Status.
0x0 = The CAN controller is not in bus-off state.
0x1 = The CAN controller is in bus-off state.
6
EWARN
R
0x0
Warning Status.
0x0 = Both error counters are below the error warning limit of 96.
0x1 = At least one of the error counters has reached the error
warning limit of 96.
5
EPASS
R
0x0
Error Passive.
0x0 = The CAN module is in the Error Active state, that is, the
receive or transmit error count is less than or equal to 127.
0x1 = The CAN module is in the Error Passive state, that is, the
receive or transmit error count is greater than 127.
4
RXOK
R/W
0x0
Received a Message Successfully. This bit must be cleared by
writing a 0 to it.
0x0 = Since this bit was last cleared, no message has been
successfully received.
0x1 = Since this bit was last cleared, a message has been
successfully received, independent of the result of the acceptance
filtering.