Lpc2000

In devices that have a Vbat pin, it powers only the RTC or the Ram 
contents is saved too ?

RTC only.

--- In lpc2000@yahoogroups.com, Mauricio Scaff <scaffm@g...> wrote:

>
> In devices that have a Vbat pin, it powers only the RTC or the Ram 
> contents is saved too ?
>

Mauricio,

on the LPC213x and LPC214x the RTC only, on the LPC2101/2/3 also the
SRAM (but afaik not the registers that do not belong to the RTC)

Bob

--- In lpc2000@yahoogroups.com, Mauricio Scaff <scaffm@g...> wrote:

>
> In devices that have a Vbat pin, it powers only the RTC or the Ram 
> contents is saved too ?
>

Hi Bob,

Where did you find that the 2101/2/3 have Vbat-backed SRAM?  I can't 
find an indication of that in the 2101/2/3 fact sheet or prelim user's 
manual.

Thanks!
Andy

--- In lpc2000@yahoogroups.com, "lpc2100_fan" <lpc2100_fan@y...> wrote:

>
> Mauricio,
> 
> on the LPC213x and LPC214x the RTC only, on the LPC2101/2/3 also the
> SRAM (but afaik not the registers that do not belong to the RTC)
> 
> Bob
> 
> --- In lpc2000@yahoogroups.com, Mauricio Scaff <scaffm@g...> wrote:
> >
> > In devices that have a Vbat pin, it powers only the RTC or the Ram 
> > contents is saved too ?
> >
>

Bob,

Hmmm, now that I think about your message I think you are correct.  
Vbat does maintain the SEC, MIN, HOUR, DOW, DOM, DOY, and etc 
registers, as well as keeping the counter ticking.

Andy

--- In lpc2000@...m, "lpc2100_fan" <lpc2100_fan@y...> wrote:

>
> Mauricio,
> 
> on the LPC213x and LPC214x the RTC only, on the LPC2101/2/3 also the
> SRAM (but afaik not the registers that do not belong to the RTC)
> 
> Bob
> 
> --- In lpc2000@yahoogroups.com, Mauricio Scaff <scaffm@g...> wrote:
> >
> > In devices that have a Vbat pin, it powers only the RTC or the Ram 
> > contents is saved too ?
> >
>

Andy,

I was interested in this myself and had the chance to talk to a
Philips designer :-))  He did not mention that this would be a hidden
feature but it sounded a lot like an official one. May be the
prliminary documentation gets an update and this option is listed. 
He told me that in the first implementation Vbat will always buffer
the 2/4/8k SRAM but later with an additional bit this is going to be
programmable whether it is RTC only or RTC + SRAM.
There seems to be a rather small difference in Vbat current and the
numbers from early Philips presentations indicate less current than
the LPC2138 / 2148 although it also buffers the SRAM.

Cheers, Bob


--- In lpc2000@yahoogroups.com, "Langosta39" <ahuska@a...> wrote:

>
> Hi Bob,
> 
> Where did you find that the 2101/2/3 have Vbat-backed SRAM?  I can't 
> find an indication of that in the 2101/2/3 fact sheet or prelim user's 
> manual.
> 
> Thanks!
> Andy
> 
> --- In lpc2000@yahoogroups.com, "lpc2100_fan" <lpc2100_fan@y...> wrote:
> >
> > Mauricio,
> > 
> > on the LPC213x and LPC214x the RTC only, on the LPC2101/2/3 also the
> > SRAM (but afaik not the registers that do not belong to the RTC)
> > 
> > Bob
> > 
> > --- In lpc2000@yahoogroups.com, Mauricio Scaff <scaffm@g...> wrote:
> > >
> > > In devices that have a Vbat pin, it powers only the RTC or the Ram 
> > > contents is saved too ?
> > >
> >
>