CAN Control Registers
1550
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
M3 Controller Area Network (CAN)
Table 23-9. Descriptions (continued)
Bit
Field
Value
Description
15-0
INT0ID
Interrupt Identifier 0. This bit field indicates the source of the interrupt.
0x0000
No interrupt is pending
0x0001-
0x020
Number of the mailbox which caused the interrupt.
0x0021-
0x7FFF
Unused
0x8000
Error and Status register value is not 0x07.
0x8001-
0xFFFF
Unused
If several interrupts are pending, the CAN Interrupt register will point to the pending interrupt
with the highest priority. The CAN0INT interrupt line remains active until INT0ID reaches value
0 (the cause of the interrupt is reset) or until IE0 is cleared. The status interrupt has the
highest priority.
A message interrupt is cleared by clearing the mailbox's IntPnd bit.
Among the message interrupts, the mailbox's interrupt priority decreases with increasing
message number.
23.15.6 Test Register (CAN TEST)
The Test register (CAN TEST) is shown and described in the figure and table below.
Figure 23-24. Test Register (CAN TEST) [offset = 0x14]
31
16
Reserved
R-0
15
10
9
8
7
6
5
4
3
2
0
Reserved
RDA
EXL
Rx
Tx[1:0]
LBack
Silent
Reserved
R-0
R/WP-
0
R/WP-
0
R-U
R/WP-0
R/WP-
0
R/WP-
0
R-0
LEGEND: R = Read; WP = Write Protected by Test bit; -
n
= value after reset; -U = Undefined
Table 23-10. Test Register Field Descriptions
Bit
Field
Value
Description
31-9
Reserved
Reserved
8
EXL
External Loopback Mode
0
Disabled
1
Enabled
7
Rx
Receive Pin. Monitors the actual value of the CAN_RX pin
0
The CAN bus is dominant
1
The CAN bus is recessive
6-5
Tx[1:0]
Control of CAN_TX pin Normal operation
00
CAN_TX is controlled by the CAN Core.
01
Sample Point can be monitored at CAN_TX pin.
10
CAN_TX pin drives a dominant value.
11
CAN_TX pin drives a recessive value.
4
LBack
Loopback Mode
0
Disabled
1
Enabled
3
Silent
Silent Mode
0
Disabled
1
Enabled