Re: TI-H: Parallel Memory expansion

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Re: TI-H: Parallel Memory expansion

Richard Piotter wrote:

> Someone mentioned IC2 before and it sounds good. TI calcs CAN interface
> with IC2, because there is a temperature sensor for the 85 based on IC2.

Hmmm, isn't it I2C? :-)

> I had the idea of parralel flash chips that would use a shiftregister to
> convert serial to parallel and back. Mel came up with such a design, but
> stoped developing it. If you can pull this off with IC2 HOOORAY FOR
> YOU!!! (-:

Welp, all of the parallel chips that I have personally found (and I have
checked most of the major electronics corporations, though not really
extensively) need ~10 I/O lines or more. As far as I know, most
serial shiftregisters are 8 bit... so you'd probably need two shift
registers or at least a 16 bit one... which I imagine would be pretty
slow in the scheme of things. And of course would not be availible
at Radio Shack. ;-)
 
> I am realy hoping that it can be done without microcontrolers, because
> they are so hard to program ($100 equipment). Every one building a

Actually, there is hardware that you can build out of parts at <cough>
RatShack </cough> for $5 or less that will burn a PIC16?84. Of course,
the PICs are pretty crappy in speed, still, they are probably the
best MCU for people who want to get started or develop quickly using
a widely supported part. It remains to be seen how quickly the AVR
will take over the PIC market. Those AVRs looks pretty sweet, though,
and if they ever reach the PIC's support in the hobbyist market I'd
tend to think microchip will be out of business. :-) Check out
atmel.com if you have no idea what the hell I'm talking about.

> microcontroller based expander seems to say that it's the best way to go
> and in many, many ways, it is, but it means you have to atleast buy the
> chip from someone. A driver would make it easy to build it yourself, and
> that's what I like. I can't help with the driver, but I will cheer you
> on. Try IC2. It might just work.

I contend that using a (do these even exist?) 16 bit serial shift
register
is just as complicated as using an 18 pin PIC16F84... a parallel EEPROM
would have even more connections than my extender, and would still
require
a complicated driver (which means it would be harder to port.) If this
were
the 1970s and microprocessors still required external RAM, ROM, and
output
drivers... perhaps... but today's MCU-in-a-box chips make using any kind
of logic almost obsolete and overly tedious.

> Also, let me know how many chips it would probably take. If it isn't to
> many, I would like to design a SPinTerface Memory Cartridge based on it.

I'd guess that it could be done with two or three.

Regards,

Bryan Rittmeyer
bryanr@flash.net
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