Table 16-20. Error and Status Register (CANES) Field Descriptions (continued)
Bit
Field
Value
Description
18
BO
Bus-off status. The CAN module is in bus-off state.
1
There is an abnormal rate of errors on the CAN bus. This condition occurs when the transmit error
counter (CANTEC) has reached the limit of 256. During Bus Off, no messages can be received or
transmitted. The bus-off state can be exited by clearing the CCR bit in CANMC register or if the
Auto Bus On (ABO) (CANMC.7) bit is set, after 128 * 11 receive bits have been received. After
leaving Bus Off, the error counters are cleared.
0
Normal operation
17
EP
Error-passive state
1
The CAN module is in error-passive mode. CANTEC has reached 128.
0
The CAN module is in error-active mode.
16
EW
Warning status
1
One of the two error counters (CANREC or CANTEC) has reached the warning level of 96.
0
Values of both error counters (CANREC and CANTEC) are less than 96.
15:6
Reserved
Reads are undefined and writes have no effect.
5
SMA
Suspend mode acknowledge. This bit is set after a latency of one clock cycle—up to the length
of one frame—after the suspend mode was activated. The suspend mode is activated with the
debugger tool when the circuit is not in run mode. During the suspend mode, the CAN module is
frozen and cannot receive or transmit any frame. However, if the CAN module is transmitting or
receiving a frame when the suspend mode is activated, the module enters suspend mode only at
the end of the frame. Run mode is when SOFT mode is activated (CANMC.16 = 1).
1
The module has entered suspend mode.
0
The module is not in suspend mode.
4
CCE
Change configuration enable. This bit displays the configuration access right. This bit is set after a
latency of one clock cycle.
1
The CPU has write access to the configuration registers.
0
The CPU is denied write access to the configuration registers.
Note:
The reset state of the CCE bit is 1. That is, upon reset, you can write to the bit timing
registers. However, once the CCE bit is cleared (as part of the module initialization), the CANRX
pin must be sensed high before you can set the CCE bit to 1 again.
3
PDA
Power-down mode acknowledge
1
The CAN module has entered the power-down mode.
0
Normal operation
2
Reserved
Reads are undefined and writes have no effect.
1
RM
Receive mode. The CAN module is in receive mode. This bit reflects what the CAN module is
actually doing regardless of mailbox configuration.
1
The CAN module is receiving a message.
0
The CAN module is not receiving a message.
0
TM
Transmit mode. The CAN module is in transmit mode. This bit reflects what the CAN module is
actually doing regardless of mailbox configuration.
1
The CAN module is transmitting a message.
0
The CAN module is not transmitting a message.
Controller Area Network (CAN)
1038
TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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