At 2004-09-15 18:15, Roger Morella wrote: >Has anyone here ever had any negative experiences with the DS1232 or >MAX1232 microprocessor watchdog chip? How reliable is this part? Is >there anything I should look out for or precautions I should take in >using this part in my design?
We once had a problem with using a watchdog chip like that in combination with a Zilog Super8 processor: The hardware designer had connected it's trigger input to bit 0 of the address bus, assuming that that would change often enough (even just reading code) to be a good indication of the CPU still being active, but it took us weeks to discover that the processor had a small code cache so that when it would execute a small delay loop (to wait for certain peripherals to stabilize, so not reading or writing data) it wouldn't read code anymore for long enough for the watchdog timer to reset the processor. This problem was very hard to find especially since the programmer/debugger (me) didn't know about this mechanism. Greetings, Jaap -- Chip Directory -- http://www.chipdir.biz/ -- http://www.chipdir.info/ -- http://www.chipdir.net/ -- http://www.chipdir.nl/ -- http://www.chipdir.org/ -- And about 30 other mirror sites world-wide. -- -- To subscribe to a free 'chip issues, questions and answers' -- mailing list, send a message to [EMAIL PROTECTED] with -- in the body 'subscribe chipdir-L'. About 500 experts are -- willing to think with you about electronics problems etc. -- Author: Jaap van Ganswijk INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
