| ??? 11/26/10 10:00 Read: times |
#179653 - Since you are considering an 805x ... Responding to: ???'s previous message |
Perhaps you'd like to consider a MAX1232 as well, since this is a popular solution to the infamous RESET problem that exists with the often recommended RC reset circuit. It has, also, a watchdog timer which must be "kicked" from time to time in order to prevent it from timing out and causing a reset. If this is combined with the internal watchdog that's often available in 805x MCU's, this might solve your problem.
If there's a regularly recurring I/O task that toggles a port pin, that can "kick" the external watchdog while an internal watchdog has to be explicitly "kicked" with an SFR access. Won't that solve your problem? If one watchdog fails, the second one is not likely to fail as well. RE |
| Topic | Author | Date |
| dual watchdog timer | 01/01/70 00:00 | |
| Scope | 01/01/70 00:00 | |
| maybe wrong site for the question but !!!!!!!!!!!!!!! | 01/01/70 00:00 | |
| You still haven't said... | 01/01/70 00:00 | |
| WDT failure | 01/01/70 00:00 | |
| Dual oscillator | 01/01/70 00:00 | |
| Do you need high reliability? | 01/01/70 00:00 | |
| IEC61508 | 01/01/70 00:00 | |
| Supervisor with WDT | 01/01/70 00:00 | |
| Since you are considering an 805x ... | 01/01/70 00:00 | |
| If one watchdog fails... | 01/01/70 00:00 | |
| the 1232 is external ... remember? | 01/01/70 00:00 | |
| Yes; that was my point - I was agreeing with you! | 01/01/70 00:00 | |
| Sorry! I didn't follow. | 01/01/70 00:00 | |
| Highly Redundant Systems | 01/01/70 00:00 | |
| a bit off the topic, but | 01/01/70 00:00 | |
| it's a matter of statistical probability | 01/01/70 00:00 | |
| Not required for 61508 | 01/01/70 00:00 | |
taken care | 01/01/70 00:00 |