DCAN Control Registers
1459
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Controller Area Network (DCAN) Module
27.17.2 Error and Status Register (DCAN ES)
Interrupts are generated by bits PER, BOff, and EWarn (if EIE bit in CAN Control Register is set) and by
bits WakeUpPnd, RxOk, TxOk, and LEC (if SIE bit in CAN Control Register is set). A change of bit EPass
will not generate an Interrupt.
NOTE:
Reading the Error and Status Register clears the WakeUpPnd, PER, RxOk and TxOk bits
and set the LEC to value of 7. Additionally, the Status Interrupt value (8000h) in the Interrupt
Register will be replaced by the next lower priority interrupt value.
For debug support, the auto clear functionality of Error and Status Register (clear of status
flags by read) is disabled when in Debug/Suspend mode.
Figure 27-21. Error and Status Register (DCAN ES) [offset = 04h]
31
16
Reserved
R-0
15
11
10
9
8
Reserved
PDA
WakeUpPnd
PER
R-0
R-0
RC-0
RC-0
7
6
5
4
3
2
0
BOff
EWarn
EPass
RxOK
TxOK
LEC
R-0
R-0
R-0
RC-0
RC-0
RS-7h
LEGEND: R = Read only; C = Clear on read; S = Set on read; -
n
= value after reset
Table 27-8. Error and Status Register (DCAN ES) Field Descriptions
Bit
Field
Value
Description
31-11
Reserved
0
These bits are always read as 0. Writes have no effect.
10
PDA
Local power down mode acknowledge.
0
DCAN is not in local power down mode.
1
Application request for setting DCAN to local power down mode was successful. DCAN is in local
power down mode.
9
WakeUp Pnd
Wake Up Pending.
This bit can be used by the CPU to identify the DCAN as the source to wake up the system.
0
No Wake Up is requested by DCAN.
1
DCAN has initiated a wake up of the system due to dominant CAN bus while module power down.
This bit will be reset if Error and Status Register is read.
8
PER
Single-/Double-bit error detected. This bit is set on double-bit errors and additionally on single-bit
errors, if single-bit error correction is disabled with the ECCMODE bitfield in the ECC Control and
Status register.
0
No single-/double-bit error has been detected since last read access.
1
The SECDED mechanism has detected a single-/double-bit error in the Message RAM. This bit will
be reset if Error and Status Register is read.
7
BOff
Bus-Off State
0
The CAN module is not Bus-Off state.
1
The CAN module is in Bus-Off state.
6
EWarn
Warning State
0
Both error counters are below the error warning limit of 96.
1
At least one of the error counters has reached the error warning limit of 96.
5
EPass
Error Passive State
0
On CAN Bus error, the DCAN could send active error frames.
1
The CAN Core is in the error passive state as defined in the CAN Specification.