| ??? 12/04/07 01:59 Read: times |
#147825 - How to make the dog happy... Responding to: ???'s previous message |
Ap said:
Kai, I have heard that tying WDT strobe signal to ALE is always a trouble , as , ALE could send false strobing signal to the WDT even in the events of hangup , I see your schematic , can you please tell me what precautions you take in this topology , I too would like to use this in my future designes as it saves a pin. The circuit was posted together with some example code here: http://www.8052.com/forum/read.phtml?id=109257 http://www.8052.com/forum/read.phtml?id=109412 As you can see, I use Port P1.4 to strobe the watchdog, not ALE. I don't use the watchdog to prevent or cure anything, but only to appease my boss! I try to design my circuits always in a way, that the watchdog need (hopefully) never to bite. It needs two edges to feed the watchdog, an 1/0-toggle and a succeeding 0/1-toggle. One way to "improve" the watchdog's performance obviously is to put the "clr p1.4" and "setb p1.4" instructions at different parts of code, so that hanging in a subroutine, for instance, will always repeat "pulses" of same polarity and by this will not still the watchdog's hunger. Kai |
| Topic | Author | Date |
| DS1232 and P89C51Rx ISP | 01/01/70 00:00 | |
| I dont know how this P89C51Rx works, but... | 01/01/70 00:00 | |
| Q for Kai | 01/01/70 00:00 | |
| I not think maybe ALE is not a good strobe | 01/01/70 00:00 | |
| Watchdogs are not as easy as they seem | 01/01/70 00:00 | |
| sure it is | 01/01/70 00:00 | |
| 1232 as only a reset supervisor, interesting idea | 01/01/70 00:00 | |
| I now think maybe ALE is not a good strobe | 01/01/70 00:00 | |
| How to make the dog happy... | 01/01/70 00:00 | |
| ALE- my apologies | 01/01/70 00:00 | |
No need to apologise, dear Ap, ... | 01/01/70 00:00 | |
| a waste of money | 01/01/70 00:00 |