LM3S1937 Datasheet, PDF (365/673 Pages) Texas Instruments – Stellaris® LM3S1937 Microcontroller

Stellaris^® LM3S1937 Microcontroller
Writing to WDTLOAD does not clear an active interrupt. An interrupt must be specifically cleared
by writing to the Watchdog Interrupt Clear (WDTICR) register.
The Watchdog module interrupt and reset generation can be enabled or disabled as required. When
the interrupt is re-enabled, the 32-bit counter is preloaded with the load register value and not its
last state.
10.3
Initialization and Configuration
To use the WDT, its peripheral clock must be enabled by setting the WDT bit in the RCGC0 register.
The Watchdog Timer is configured using the following sequence:
1. Load the WDTLOAD register with the desired timer load value.
2. If the Watchdog is configured to trigger system resets, set the RESEN bit in the WDTCTL register.
3. Set the INTEN bit in the WDTCTL register to enable the Watchdog and lock the control register.
If software requires that all of the watchdog registers are locked, the Watchdog Timer module can
be fully locked by writing any value to the WDTLOCK register. To unlock the Watchdog Timer, write
a value of 0x1ACC.E551.
10.4
Register Map
Table 10-1 on page 365 lists the Watchdog registers. The offset listed is a hexadecimal increment
to the register’s address, relative to the Watchdog Timer base address of 0x4000.0000.
Table 10-1. Watchdog Timer Register Map
Offset Name
Type
Reset
Description
0x000 WDTLOAD
0x004 WDTVALUE
0x008 WDTCTL
0x00C WDTICR
0x010 WDTRIS
0x014 WDTMIS
0x418 WDTTEST
0xC00 WDTLOCK
0xFD0 WDTPeriphID4
0xFD4 WDTPeriphID5
0xFD8 WDTPeriphID6
0xFDC WDTPeriphID7
0xFE0 WDTPeriphID0
0xFE4 WDTPeriphID1
0xFE8 WDTPeriphID2
R/W
0xFFFF.FFFF Watchdog Load
RO
0xFFFF.FFFF Watchdog Value
R/W
0x0000.0000 Watchdog Control
WO
-
Watchdog Interrupt Clear
RO
0x0000.0000 Watchdog Raw Interrupt Status
RO
0x0000.0000 Watchdog Masked Interrupt Status
R/W
0x0000.0000 Watchdog Test
R/W
0x0000.0000 Watchdog Lock
RO
0x0000.0000 Watchdog Peripheral Identification 4
RO
0x0000.0000 Watchdog Peripheral Identification 5
RO
0x0000.0000 Watchdog Peripheral Identification 6
RO
0x0000.0000 Watchdog Peripheral Identification 7
RO
0x0000.0005 Watchdog Peripheral Identification 0
RO
0x0000.0018 Watchdog Peripheral Identification 1
RO
0x0000.0018 Watchdog Peripheral Identification 2
See
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June 18, 2012
365
Texas Instruments-Production Data