| ??? 07/25/06 19:54 Read: times |
#121040 - yet questions more Responding to: ???'s previous message |
hi,
Oleg Sergeev said:
How this interrupt is long in time:/*timer 1...
Tulika Kumar said:
As multiplexing of four 7-segment displays had to be done thus,consecutive display is lit up every 2.5 ms.So each display is lit up after every 10 ms.
The question is not about frequency of refresh; it is about how ISR (interrupt service routine) is long itself from vector jump upto RETI. Is it possible that execution of the ISR is longer than ~2ms more or less sometimes? I havent included any priority code,interrupts follow thier default priority.how to include it?it may help.
Yes, you should try to set timer 2 priority to high level to check the problem. If this goes out then the problem is in over-load of MCU productivity due your interrupts` code programming. And so you need to re-arrange your code of ISRs -- read Erik`s `KISS` translation, or select faster MCU/crystal. To select interrupt priority read AT89 Hardware manual. Due some reason this document cannot be located at Atmel site for now but there is its copy, for example, here: http://www.csd.uoc.gr/~hy325/spring-2006/docs/doc0499.pdf (take a look from page 2-58 and down). Regards, Oleg |
| Topic | Author | Date |
| problem in timer with a least count of 1 millisec | 01/01/70 00:00 | |
| Code as shown should work methinks | 01/01/70 00:00 | |
| clarifications | 01/01/70 00:00 | |
| atomicity | 01/01/70 00:00 | |
| atomicity problem? | 01/01/70 00:00 | |
| about atomicity | 01/01/70 00:00 | |
| Back to basic | 01/01/70 00:00 | |
| reply to vishal sinha | 01/01/70 00:00 | |
| bible time | 01/01/70 00:00 | |
| Hm ... | 01/01/70 00:00 | |
| reply to Christoph Franck | 01/01/70 00:00 | |
| totally imprecse | 01/01/70 00:00 | |
| What is the size of the variables? | 01/01/70 00:00 | |
| not enough info | 01/01/70 00:00 | |
| other details about code | 01/01/70 00:00 | |
| here you go again | 01/01/70 00:00 | |
yet questions more | 01/01/70 00:00 |