SRAM
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Posts: 46,084
While salvaging for parts for my robot project, I came across a 64K
nonvolatile SRAM chip. Is anyone using SRAM in one of their projects? If
usable, what are the basic issues for working with one of these chips? The
chip is a Dallas Semiconductor DS1225AD-200.
Rafe
nonvolatile SRAM chip. Is anyone using SRAM in one of their projects? If
usable, what are the basic issues for working with one of these chips? The
chip is a Dallas Semiconductor DS1225AD-200.
Rafe
Comments
control 15 bits of addressing pins, the 8 data pins, as well as the
Output-Enable and Input-Enable pins. If you want to save power,
you'll also want to use the Chip-Enable pin. This is a total of 25
pins (26 with /ce) so obviously you wouldn't be able to do it with
just a stamp. For SRAM I use an Atmel AVR chip (AT90S8515) along
with a 74HC573 latch. This is a 40-pin chip though, so there's
plenty of extra pins. For a stamp you may want to use 2 shift
registers for addressing and /CE, as well as 2 pins for /WR and /RD
and 8 for I/O. This should be a total of 16 pins, which
unfortunately is the entire stamp.
--- In basicstamps@y..., "Rafe" <rafe00@e...> wrote:
> While salvaging for parts for my robot project, I came across a 64K
> nonvolatile SRAM chip. Is anyone using SRAM in one of their
projects? If
> usable, what are the basic issues for working with one of these
chips? The
> chip is a Dallas Semiconductor DS1225AD-200.
>
>
> Rafe
$99
Original Message
From: <pyromaneyakk@h...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, October 03, 2001 6:58 PM
Subject: [noparse][[/noparse]basicstamps] Re: SRAM
> My main project right now involves an SRAM controller. You need to
> control 15 bits of addressing pins, the 8 data pins, as well as the
> Output-Enable and Input-Enable pins. If you want to save power,
> you'll also want to use the Chip-Enable pin. This is a total of 25
> pins (26 with /ce) so obviously you wouldn't be able to do it with
> just a stamp. For SRAM I use an Atmel AVR chip (AT90S8515) along
> with a 74HC573 latch. This is a 40-pin chip though, so there's
> plenty of extra pins. For a stamp you may want to use 2 shift
> registers for addressing and /CE, as well as 2 pins for /WR and /RD
> and 8 for I/O. This should be a total of 16 pins, which
> unfortunately is the entire stamp.
>
> --- In basicstamps@y..., "Rafe" <rafe00@e...> wrote:
> > While salvaging for parts for my robot project, I came across a 64K
> > nonvolatile SRAM chip. Is anyone using SRAM in one of their
> projects? If
> > usable, what are the basic issues for working with one of these
> chips? The
> > chip is a Dallas Semiconductor DS1225AD-200.
> >
> >
> > Rafe
>
>
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>
an 8-bit shift register be used for data I/O, as well
as a 16-bit SR for addressing, with the Stamp in the
serial side of both? A read op might be 1) shiftout
address to SR1; 2) tell SRAM to read using /RD pin; 3)
shiftin data from SR2. A write would have the same
first step, then 2) shiftout data to write to SR2; 3)
tell SRAM to write using /WR. Pins would be CE, RD,
WR, SR1_dat, SR2_dat, and SClk, 6 total.
Bob Pence
--- capdiamont <capdiamont@m...> wrote:
> there is a 40 pin version of a stamp, with 32 i/o
> lines, costly though, at
> $99
>
Original Message
> From: <pyromaneyakk@h...>
> To: <basicstamps@yahoogroups.com>
> Sent: Wednesday, October 03, 2001 6:58 PM
> Subject: [noparse][[/noparse]basicstamps] Re: SRAM
>
>
> > My main project right now involves an SRAM
> controller. You need to
> > control 15 bits of addressing pins, the 8 data
> pins, as well as the
> > Output-Enable and Input-Enable pins. If you want
> to save power,
> > you'll also want to use the Chip-Enable pin. This
> is a total of 25
> > pins (26 with /ce) so obviously you wouldn't be
> able to do it with
> > just a stamp. For SRAM I use an Atmel AVR chip
> (AT90S8515) along
> > with a 74HC573 latch. This is a 40-pin chip
> though, so there's
> > plenty of extra pins. For a stamp you may want to
> use 2 shift
> > registers for addressing and /CE, as well as 2
> pins for /WR and /RD
> > and 8 for I/O. This should be a total of 16 pins,
> which
> > unfortunately is the entire stamp.
> >
> > --- In basicstamps@y..., "Rafe" <rafe00@e...>
> wrote:
> > > While salvaging for parts for my robot project,
> I came across a 64K
> > > nonvolatile SRAM chip. Is anyone using SRAM in
> one of their
> > projects? If
> > > usable, what are the basic issues for working
> with one of these
> > chips? The
> > > chip is a Dallas Semiconductor DS1225AD-200.
> > >
> > >
> > > Rafe
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
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Barry Michels posted a super project for interfacing to parallel
memory (CF+sram), using 82C55 PIO chips to cut down on the number of
lines required. If you look at the bottom part of his posted
schematic, it is an interface to a '6264 8 kbyte ram.
http://www.barrymichels.com/ide
-- Tracy
>While salvaging for parts for my robot project, I came across a 64K
>nonvolatile SRAM chip. Is anyone using SRAM in one of their projects? If
>usable, what are the basic issues for working with one of these chips? The
>chip is a Dallas Semiconductor DS1225AD-200.
>
>
>Rafe