Vault 7: Projects

This publication series is about specific projects related to the Vault 7 main publication.

PIC24F Family Reference Manual
DS39697B-page 9-2 © 2010 Microchip Technology Inc.
9.1 INTRODUCTION
The primary function of the Watchdog Timer (WDT) is to reset the microcontroller, in the event of
a software malfunction, by resetting the device if it has not been cleared in software. It can also
be used to wake the device from Sleep or Idle mode. The WDT is a free-running timer which uses
the low-power RC oscillator and requires no external components. Therefore, the WDT will con-
tinue to operate even if the system’s primary clock source (e.g., the crystal oscillator) is stopped
under normal operation (e.g., in Sleep mode).
A block diagram of the WDT is shown in Figure 9-1.
Figure 9-1: WDT Block Diagram
Note: This family reference manual section is meant to serve as a complement to device
data sheets. Depending on the device variant, this manual section may not apply
to all PIC24F devices.
Please consult the note at the beginning of the Watchdog Timer (WDT)” chapter
in the current device data sheet to check whether this document supports the
device you are using.
Device data sheets and family reference manual sections are available for
download from the Microchip Worldwide Web site at: http://www.microchip.com
LPRC Input
WDT Overflow
Wake from Sleep
31 kHz
Prescaler
Postscaler
WDTPRE
SWDTEN
FWDTEN
Reset
All Device Resets
Sleep or Idle Mode
LPRC Control
CLRWDT
PWRSAV
(5-bit/7-bit)
1:1 to 1:32.768
WDTPOST<3:0>
1 ms/4 ms
Exit Sleep or
Idle Mode
WDT
Counter
Transition to
New Clock Source

e-Highlighter

Click to send permalink to address bar, or right-click to copy permalink.

Un-highlight all Un-highlight selectionu Highlight selectionh