MMC2107 - Freescale Semiconductor

Freescale Semiconductor, Inc.
Technical Data — MMC2107
Section 13. Watchdog Timer Module
13.1 Contents
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Freescale Semiconductor, I
13.2 Introduction
13.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .271
13.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
13.3.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
13.3.2 Doze Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
13.3.3 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
13.3.4 Debug Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
13.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .273
13.5 Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .273
13.6 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . .274
13.6.1 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .274
13.6.2 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .274
13.6.2.1 Watchdog Control Register . . . . . . . . . . . . . . . . . . . . . .275
13.6.2.2 Watchdog Modulus Register . . . . . . . . . . . . . . . . . . . . .277
13.6.2.3 Watchdog Count Register . . . . . . . . . . . . . . . . . . . . . . .278
13.6.2.4 Watchdog Service Register . . . . . . . . . . . . . . . . . . . . . .279
The watchdog timer is a 16-bit timer used to help software recover from
runaway code. The watchdog timer has a free-running down-counter
(watchdog counter) that generates a reset on underflow. To prevent a
reset, software must periodically restart the countdown.
MMC2107 – Rev. 2.0 Technical Data
MOTOROLA Watchdog Timer Module 271
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