DCAN Registers
23.4.2 ES Register (offset = 04h) [reset = 6Fh]
ES is shown in
and described in
.
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. Reading the error and status register clears the WakeUpPnd, PER, RxOk and
TxOk bits and set the LEC to value '7.' Additionally, the status interrupt value (0x8000) in the interrupt
register will be replaced by the next lower priority interrupt value. The EOI for all other interrupts
(DCANINT0 and DCANINT1) are automatically handled by hardware. 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 23-20. ES Register
31
30
29
28
27
26
25
24
Reserved
R-0h
23
22
21
20
19
18
17
16
Reserved
R-0h
15
14
13
12
11
10
9
8
Reserved
PDA
WakeUp_Pnd
PER_
R-0h
R-0h
R/C-0h
R/C-0h
7
6
5
4
3
2
1
0
BOff
EWarn
EPass
RxOk
TxOk
LEC
R-0h
R-1h
R-1h
R/C-0h
R/C-1h
R/S-7h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 23-15. ES Register Field Descriptions
Bit
Field
Type
Reset
Description
31-11
Reserved
R
0h
10
PDA
R
0h
Local power-down mode acknowledge
0x0 = DCAN is not in local power-down mode.
0x1 = Application request for setting DCAN to local power-down
mode was successful. DCAN is in local power-down mode.
9
WakeUp_Pnd
R/C
0h
Wake up pending.
This bit can be used by the CPU to identify the DCAN as the source
to wake up the system.
This bit will be reset if error and status register is read.
0x0 = No Wake Up is requested by DCAN.
0x1 = DCAN has initiated a wake up of the system due to dominant
CAN bus while module power down.
8
PER_
R/C
0h
Parity error detected.
This bit will be reset if error and status register is read.
0x0 = No parity error has been detected since last read access.
0x1 = The parity check mechanism has detected a parity error in the
Message RAM.
7
BOff
R
0h
Bus-Off state
0x0 = The CAN module is not bus-off state.
0x1 = The CAN module is in bus-off state.
6
EWarn
R
1h
Warning state
0x0 = Both error counters are below the error warning limit of 96.
0x1 = At least one of the error counters has reached the error
warning limit of 96.
3927
SPRUH73H – October 2011 – Revised April 2013
Controller Area Network (CAN)
Copyright © 2011–2013, Texas Instruments Incorporated