
M0A21/M0A23 Series
May 06, 2022
Page
319
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
TOUTSEL
Time-Out Interval Period
T
TIS
Reset Delay Period
T
RSTD
000
2
4
* T
WDT
(3/18/130/1026) * T
WDT
001
2
6
* T
WDT
(3/18/130/1026) * T
WDT
010
2
8
* T
WDT
(3/18/130/1026) * T
WDT
011
2
10
* T
WDT
(3/18/130/1026) * T
WDT
100
2
12
* T
WDT
(3/18/130/1026) * T
WDT
101
2
14
* T
WDT
(3/18/130/1026) * T
WDT
110
2
16
* T
WDT
(3/18/130/1026) * T
WDT
111
2
18
* T
WDT
(3/18/130/1026) * T
WDT
1000
2
20
* T
WDT
(3/18/130/1026) * T
WDT
Table 6.8-1 Watchdog Timer Time-out Interval Period Selection
T
TIS
WDT reset
(low reset)
T
RSTD
T
RST
T
WDT
T
WDT
: Watchdog Clock Time Period
T
TIS
: Watchdog Time-out Interval Period ( (2
4
~ 2
20
) * T
WDT
)
T
RSTD
: Watchdog Reset Delay Period
- Selectable 3/18/130/1026 * T
WDT
delay period controlled
by RSTDSEL(WDT_ALTCTL [1:0])
T
RST
: Watchdog Reset Period ( 63 * T
WDT
)
WDT_CLK
IF = 1
RSTF = 1
(if RSTEN = 1)
IF
(WDT_CTL[3])
RSTF
(WDT_CTL[2])
RSTEN
(WDT_CTL[1])
Figure 6.8-3 Watchdog Timer Time-out Interval and Reset Period Timing
6.8.5.3
WDT Wake-up
If WDT clock source is selected to LIRC or LXT, system can be woken up from Power-down mode while
WDT time-out interrupt signal is generated and WKEN (WDT_CTL[4]) enabled. Note that user should
set LXTEN (CLK_PWRCTL [1]) or LIRCEN (CLK_PWRCTL [3]) to select clock source before system
enters Power-down mode because the system peripheral clock are disabled when system is in Power-
down mode. In the meanwhile, the WKF (WDT_CTL[5]) will be set to 1 automatically, and user can
check WKF (WDT_CTL[5]) status by software to recognize the system has been woken up by WDT
time-out interrupt or not.