Texas Instruments MSP430x1xx, User Manual

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Watchdog Timer Registers
10-8 Watchdog Timer
WDTCTL, Watchdog Timer Register
15 14 13 12 11 10 9 8
Read as 069h
WDTPW, must be written as 05Ah
7 6 5 4 3 2 1 0
WDTHOLD WDTNMIES WDTNMI WDTTMSEL WDTCNTCL WDTSSEL WDTISx
rw−0 rw−0 rw−0 rw−0 r0(w) rw−0 rw−0 rw−0
WDTPW Bits
15-8 Watchdog timer password. Always read as 069h. Must be written as 05Ah, or
a PUC will be generated.
WDTHOLD Bit 7 Watchdog timer hold. This bit stops the watchdog timer. Setting WDTHOLD
= 1 when the WDT is not in use conserves power.
0
Watchdog timer is not stopped
1 Watchdog timer is stopped
WDTNMIES Bit 6 Watchdog timer NMI edge select. This bit selects the interrupt edge for the
NMI interrupt when WDTNMI = 1. Modifying this bit can trigger an NMI. Modify
this bit when WDTNMI = 0 to avoid triggering an accidental NMI.
0
NMI on rising edge
1 NMI on falling edge
WDTNMI Bit 5 Watchdog timer NMI select. This bit selects the function for the RST/NMI pin.
0
Reset function
1 NMI function
WDTTMSEL Bit 4 Watchdog timer mode select
0
Watchdog mode
1 Interval timer mode
WDTCNTCL Bit 3 Watchdog timer counter clear. Setting WDTCNTCL = 1 clears the count value
to 0000h. WDTCNTCL is automatically reset.
0
No action
1 WDTCNT = 0000h
WDTSSEL Bit 2 Watchdog timer clock source select
0
SMCLK
1 ACLK
WDTISx Bits
1-0 Watchdog timer interval select. These bits select the watchdog timer interval
to set the WDTIFG flag and/or generate a PUC.
00
Watchdog clock source /32768
01 Watchdog clock source /8192
10 Watchdog clock source /512
11 Watchdog clock source /64