DCAN Control Registers
1090
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Controller Area Network (DCAN) Module
23.17.9 Auto-Bus-On Time Register (DCAN ABOTR)
Figure 23-27. Auto-Bus-On Time Register (DCAN ABOTR) [offset = 80h]
31
16
ABO_TIME
R/W-0
15
0
ABO_TIME
R/W-0
LEGEND: R/W = Read/Write; -
n
= value after reset
Table 23-15. Auto-Bus-On Time Register Field Descriptions
Bit
Field
Value
Description
31-0
ABO_TIME
0-FFFF FFFFh
Number of VBUS clock cycles before a Bus-Off recovery sequence is started by
clearing the Init bit. This function has to be enabled by setting the ABO bit in the
CAN Control Register.
The Auto-Bus-On timer is realized by a 32-bit counter that starts to count down to
0 when the module goes Bus-Off.
The counter will be reloaded with the preload value of the ABO_TIME register
after this phase.
NOTE:
On write access to the CAN Control register while Auto-Bus-On timer is running, the Auto-
Bus-On procedure will be aborted.
During Debug/Suspend mode, running Auto-Bus-On timer will be paused.
23.17.10 Transmission Request X Register (DCAN TXRQ X)
With the Transmission Request X Register, the CPU can detect if one or more bits in the different
Transmission Request Registers are set. Each register bit represents a group of eight message objects. If
at least one of the TxRqst bits of these message objects are set, the corresponding bit in the
Transmission Request X Register will be set.
Figure 23-28. Transmission Request X Register (DCAN TXRQ X) [offset = 84h]
31
16
Reserved
R-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
TxRqstReg8
TxRqstReg7
TxRqstReg6
TxRqstReg5
TxRqstReg4
TxRqstReg3
TxRqstReg2
TxRqstReg1
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -
n
= value after reset
Example
Bit 0 of the Transmission Request X Register represents byte 0 of the Transmission Request 1 Register
(DCAN TXRQ12). If one or more bits in this byte are set, bit 0 of the Transmission Request X Register will
be set.