Marco Antonio Simon dal Poz wrote:
>
> On Wed, 7 Oct 1998, MetalGear wrote:
>
> > De : Gabriel D. <[EMAIL PROTECTED]>
> > Date : mercredi 7 octobre 1998 12:18
> >
> >
> > >1. I�m wondering how is the SRAM memory of Panasonic FM-PAC kept alive?
> > >Is there a battery (rechargeable?) inside ?
> > >I just don�t dare to splity my cartridge to check :-)
> >
> >
> > SRAM = Static-RAM , doesn't need any power to keep data, but only to change
> > the stored bit value. I'm sure you can find lot of information about SRAM
> > (AFAIK called FLASH in some commercial products) functionning.
> >
> > if I'm wrong, I hope to receive a copy of the correct information ;-)
>
> Ok, so, you're wrong! SRAM needs power to keep data. Probably you're
> talking about DRAM, whose current exists when the stored bit change. But
> DRAM keeps data in its internal capacitances, and how things aren't
> perfect, there's also some internal resistances, that drains slowly the
> electrical charge of the bits. So, it's necessary a refresh to recharge
> each bit-cell of DRAM.
DRAM ? Even worse ! D-RAM needs refresh circuit , a address demux
circuit
and wastes a lot of power .....
About the FM-PAC SRAM ... It isn�t a CR2032 type. It is a BR2325
(Rechargeable)
And below it there is a watchdog circuit with diodes wich recarges it.
It�s impossible to a CR2032 lasts more than 5 years ... it discharges
itself
though it�s internal resistance + S-RAM consumption.
So don�t worry about changing your�s FM-PAC battery !
That�s all .... :)
--
Leonard Silva de Oliveira MSX user since 1987
MSX users channel on the undernet : #MSX the MSX user's channel
Nickname : Vic_Viper
[EMAIL PROTECTED]
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