DocID018909 Rev 11
RM0090
Controller area network (bxCAN)
1112
CAN bit timing register (CAN_BTR)
Address offset: 0x1C
Reset value: 0x0123 0000
This register can only be accessed by the software when the CAN hardware is in
initialization mode.
Bit 2
BOFF
:
Bus-off flag
This bit is set by hardware when it enters the bus-off state. The bus-off state is entered on
TEC overflow, greater than 255, refer to
Bit 1
EPVF
: Error passive flag
This bit is set by hardware when the Error Passive limit has been reached (Receive Error
Counter or Transmit Error Counter>127).
Bit 0
EWGF
:
Error warning flag
This bit is set by hardware when the warning limit has been reached
(Receive Error Counter or Transmit Error Counter
≥
96).
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
SILM
LBKM
Reserved
SJW[1:0]
Res.
TS2[2:0]
TS1[3:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Reserved
BRP[9:0]
rw
rw
rw
rw
rw
rw
rw
rw
rw
rw
Bit 31
SILM
:
Silent mode (debug)
0: Normal operation
1: Silent Mode
Bit 30
LBKM
:
Loop back mode (debug)
0: Loop Back Mode disabled
1: Loop Back Mode enabled
Bits 29:26 Reserved, must be kept at reset value.
Bits 25:24
SJW[1:0]
:
Resynchronization jump width
These bits define the maximum number of time quanta the CAN hardware is allowed to
lengthen or shorten a bit to perform the resynchronization.
t
RJW
= t
q
x (SJW[1:0] + 1)
Bit 23 Reserved, must be kept at reset value.
Bits 22:20
TS2[2:0]
:
Time segment 2
These bits define the number of time quanta in Time Segment 2.
t
BS2
= t
q
x (TS2[2:0] + 1)