Re: A86: Batt Checker
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Re: A86: Batt Checker
Dux Gregis wrote:
> The main CPU clock becomes slower because it is used much more frequently
> ... it has to send signals out all the time. The interrupt clock, though,
> only has to send signals once every interrupt.
Not properly... the interrupt signal could have been derivated from
the same clock source as the z80 clock, dy a hardware divisor. In this
case,
both clocks would maintain sincrony and no one would get slower tha
the
other. Normally, if we need more than clock frequency in a system we
use one single clock and divide to obtain the others, unless there's
some special reason to have separate clocks.
Crystal oscilators are used to make clocks that maintain the frequency
fixed, even with rather large voltage power. Clocks that vary in
frequency
with the power voltage are normally 'RC' oscilators.
I got in front of me a manual from a certain microcontroler, wich has
some
graphics of Frequency/Voltage(power) for an RC clock. For a variation
of
1.5V in the power, the frequency can low down more than 1MHz.
One reason can think of for TI not using a crystal clock is space. But
why
spare... well, I realise now that I'm too much out of knoledge to
speculate.
I still have my first batterys, so, does the calc slow down when the
batterys are low?
> The CPU clock must increment once every t-state where the interrupt clock
> (I'm not completely sure about this) is controlled by a less power intensive
> _external_ clock. Everything runs on the same batteries, so the things in
> hardware that consume the least amount of power are going to be the most
> accurate.
NSJ aka Viriato
l41324@alfa.ist.utl.pt
nmasj@camoes.rnl.ist.utl.pt
http://camoes.rnl.ist.utl.pt/~nmasj - DemoAdict/TaradoPorDemos
References: