> Antonio Almeida wrote:
> >
> >         Are there any SPI RAMs width some Kbytes ? If not, is any
> > "friendly" way to use normal RAMs width the PIC (i mean, using not to much
> > pins) ?
> >
>
> I red an article about DALLAS DS 1380/1381. It have 2k x 8bit.
> It have two 8 bit Ports and 2 control lines. Over the first port
> the PIC can supply Adress/Data. In a 'transparent' mode the 8
> lines of the PIC can be switched through to the second port an
> can be used as normal port pins. So you effective need two
> pins on the PIC for the control signals.

A very accurate description. A couple of more observations:

1) It takes three data moves to transfer data to/from the RAM
2) The 1380/81 IO pins doesn't have the same load capacity as the PICs
3) the 81 is battery backed internally. The 1380 has pins for adding a
backup battery.
4) Data sheets are available from the Dallas Semi website.

>
> I don't have any price information on this chip.

You can buy in ones/twos directly from DallasSemi. Last I checked the
1380 was in the $9 ballpark while the 1381 was $11 or so.

BAJ