8-bit MicrocontrollersのトピックRe: Variation of RTI interrupt time due variation in clk source ?

Variation of RTI interrupt time due variation in clk source ? S08AW32

Denn — Sat, 08 Mar 2008 19:21:57 GMT

Hello,

From Data sheet of AW32 i see that Real Time Intr clock source (1kHz) can have a deviation of 30%in period from 700us to 1300us, while desired is 1000us.

I have selected the duration of interrupt to be 8ms.

So I would like to know the relation of clock source and the intr occurance period(ideal 8ms) and hence the change in intr occurance period due to change in clk source.

Any equations relating the clk src and intr occurance period ?

Regards,
Denn

Added p/n to subject.

Message Edited by NLFSJ on 2008-03-10 03:11 PM

Re: Variation of RTI interrupt time due variation in clk source ?

JimDon — Sun, 09 Mar 2008 02:18:30 GMT

I'd say 30%. Since you are just dividing down the clock, it will have the same amount variation.

In other words 8*700us is the low value and 8*1200us is the high value.

Re: Variation of RTI interrupt time due variation in clk source ?

Denn — Mon, 10 Mar 2008 17:46:05 GMT

Hello Jim,

Even I think so.More over there is no eqn of how it is divided (hopefully the clk source and the interrupt occurance are linearly related without any constants adding to dividers.)

I think the high value should be 8*1.300 ms

Regards,

Denn

Re: Variation of RTI interrupt time due variation in clk source ?

JimDon — Mon, 10 Mar 2008 21:56:49 GMT

Your right I meant 8*1300us.
Sorry typo.

Well, if it is a 1ms clock to start with, and it becomes 8ms, the equ is "divided by 8".

Re: Variation of RTI interrupt time due variation in clk source ?

Denn — Tue, 11 Mar 2008 22:01:54 GMT

Ya.. you are right Jim.

Denn