| ??? 10/02/12 20:20 Read: times |
#188544 - Timer ISR Counter Responding to: ???'s previous message |
So what if was want to generate a delay that's greater than 65 ms?
set the timer for e.g. 10ms and increment/decrement a counter in the Timers ISR It is indeed the conventional way to do this. It is rather surprising how many times a question like this is asked!! A new user sees that a timer runs out of duration shorter than the total delay that they wanted and then almost think they need to find an MCU with a longer counter!! If, as suggested by Erik, you set the timer ISR to fire off once each 10 milliseconds then a software manintained counter in the timer ISR that is 16-bits wide can indicate a time delay out to 65,535 * 10ms = 655.35 seconds. This is over 10 minutes!! A 24-bit wide counter in the timer ISR could support a delay out to 16,777,215 * 10ms = 167,772.15 seconds. This is over 45 hours. Michael Karas |
| Topic | Author | Date |
| Maximum possible delay using a Timer | 01/01/70 00:00 | |
| are you sure? | 01/01/70 00:00 | |
| Timer ISR Counter | 01/01/70 00:00 | |
The answer is chip dependant | 01/01/70 00:00 |