There has recently been a lot of discussion on this forum about the subject of watch dog timers (WDTs) and how they should be implemented. Some people proclaim that software traps and various other software techniques such as self validate and soft reset are a worth while effort for an embedded project. Here are some links to threads where some of this discussion has taken place....

Sample #1

Michael Karas


Sample #2

Sample #3

I happen to believe that most rechniques that are commonly used are less than adequate solutions if not down right worthless. Thus it was with great interest and agreement with which I read a recent article in Embedded Systems written by Jack Ganssle on the subject of watch dog timers. If you should be so inclined you can read it too at this link --> Li'l Bow Wow by Jack Ganssle