AHA! -- Lawrence Lile Dale Botkin Sent by: pic microcontroller discussion list 08/28/02 02:19 PM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: Subject: Re: [PIC]:problem with Watch-Dog On Wed, 28 Aug 2002, Olin Lathrop wrote: > > Yes, but fiddling with the PSA bit can cause an unintended WDT reset even > > if it's disabled, apparently. > > I find that *very* hard to believe. Do you have any solid evidence to > support this belief? Well, yes, otherwise I wouldn't have said it. As the OP noted, you can look at section 11.6.1 on page 11-8 of DS31101A, the PIC Midrange reference manual. "NOTE: To avoid an unintended device RESET, the following instruction sequence (shown in Example 11-1) must be executed when changing the prescaler assignment from TIMER0 to the WDT. This sequence must be followed even if the WDT is disabled." I'd say that explains why he gets a WDT reset when he manually twiddles PSA even though he's got the WDT disabled. I had to look it up to be sure, but there it is plain as day. Dale -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu