DCAN Control Registers
1462
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Controller Area Network (DCAN) Module
27.17.4 Bit Timing Register (DCAN BTR)
NOTE:
This register is only writable if CCE and Init bits in the CAN Control Register are set.
The CAN bit time may be programmed in the range of 8 to 25 time quanta.
The CAN time quantum may be programmed in the range of 1 to 1024 CAN_CLK periods.
With a CAN_CLK of 8 MHz and BRPE = 00, the reset value of 2301h configures the DCAN for a bit rate of
500kBit/s.
For details see
.
Figure 27-23. Bit Timing Register (DCAN BTR) [offset = 0Ch]
31
20
19
16
Reserved
BRPE
R-0
R/WP-0
15
14
12
11
8
7
6
5
0
Rsvd
TSeg2
TSeg1
SJW
BRP
R-0
R/WP-2h
R/WP-3h
R/WP-0
R/WP-1h
LEGEND: R/W = Read/Write; R = Read only; WP = Write Protected by CCE bit; -
n
= value after reset
Table 27-10. Bit Timing Register (DCAN BTR) Field Descriptions
Bit
Field
Value
Description
31-20
Reserved
0
These bits are always read as 0. Writes have no effect.
BRPE
0-Fh
Baud Rate Prescaler Extension.
Valid programmed values are 0 to 15. By programming BRPE the Baud Rate Prescaler can be
extended to values up to 1024.
15
Reserved
0
This bit is always read as 0. Writes have no effect.
14-12
TSeg2
0-7h
Time segment after the sample point.
Valid programmed values are 0 to 7. The actual TSeg2 value that is interpreted for the Bit Timing
will be the programmed TSeg2 value + 1.
11-8
TSeg1
1h-Fh
Time segment before the sample point.
Valid programmed values are 1 to 15. The actual TSeg1 value interpreted for the Bit Timing will be
the programmed TSeg1 value + 1.
7-6
SJW
0-3h
Synchronization Jump Width
Valid programmed values are 0 to 3. The actual SJW value interpreted for the Synchronization will
be the programmed SJW value + 1.
5-0
BRP
0-3Fh
Baud Rate Prescaler
Value by which the CAN_CLK frequency is divided for generating the bit time quanta. The bit time
is built up from a multiple of this quanta. Valid programmed values are 0 to 63. The actual BRP
value interpreted for the Bit Timing will be the programmed BRP value + 1.