WDT_A Registers
763
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Watchdog Timer (WDT_A)
17.3.1 WDTCTL Register
Watchdog Timer Control Register
Figure 17-2. WDTCTL Register
15
14
13
12
11
10
9
8
WDTPW
rw-{0}
rw-{1}
rw-{1}
rw-{0}
rw-{1}
rw-{0}
rw-{0}
rw-{1}
7
6
5
4
3
2
1
0
WDTHOLD
WDTSSEL
WDTTMSEL
WDTCNTCL
WDTIS
rw-{0}
rw-{0}
rw-{0}
rw-{0}
rw-{0}
rw-{1}
rw-{0}
rw-{0}
(1)
Writes to this registers must be 16 bits wide; otherwise, the WDT_A generates a reset.
(2)
Clock requests to ACLK and SMCLK clocks in watchdog mode of operation are unconditional clock requests. So disabling the
corresponding clock enable bits in CS does not stop the clock to the WDT_A module.
(3)
In the Interval time mode, ACLK and SMCLK clock requests are always conditional from WDT_A module.
Table 17-3. WDTCTL Register Description
(1)
Bit
Field
Type
Reset
Description
15-8
WDTPW
RW
69h
Watchdog timer password. Always read as 069h. Must be written as 05Ah, or the
WDT generates a reset.
7
WDTHOLD
RW
0h
Watchdog timer hold. This bit stops the watchdog timer. Setting WDTHOLD = 1
when the WDT is not in use conserves power.
0b = Watchdog timer is not stopped
1b = Watchdog timer is stopped
6-5
WDTSSEL
RW
0h
Watchdog timer clock source select
00b = SMCLK
01b = ACLK
10b = VLOCLK
11b = BCLK
4
WDTTMSEL
RW
0h
Watchdog timer mode select
0b = Watchdog mode
(2)
1b = Interval timer mode
(3)
3
WDTCNTCL
W
0h
Watchdog timer counter clear. Setting WDTCNTCL = 1 clears the count value to
0000h. This bit always reads 0h
0b = No action
1b = WDTCNT = 0000h
2-0
WDTIS
RW
4h
Watchdog timer interval select. These bits select the watchdog timer interval to
generate either a WDT interrupt or a WDT reset .
000b = Watchdog clock source / 2
31
(18:12:16 at 32.768 kHz)
001b = Watchdog clock source / 2
27
(01:08:16 at 32.768 kHz)
010b = Watchdog clock source / 2
23
(00:04:16 at 32.768 kHz)
011b = Watchdog clock source / 2
19
(00:00:16 at 32.768 kHz)
100b = Watchdog clock source / 2
15
(1 s at 32.768 kHz)
101b = Watchdog clock source / 2
13
(250 ms at 32.768 kHz)
110b = Watchdog clock source / 2
9
(15.625 ms at 32.768 kHz)
111b = Watchdog clock source / 2
6
(1.95 ms at 32.768 kHz)