> I'm working on a project where I need to hook up an EEPROM chip to a
> PIC16C84 and I need to know how the interface works between the PIC and
> the EEPROM probably XI2C Bus. If anyone can explain how it works, or
> knows a webpage or something that explains it I would appreciate it.
> Thanks.
>
>         Chris
>
>
> _____________________________________________________________________
> I'm, like, a product, OK, of american, you know, education, all right?
> .....DJ_RamenKILLspam.....juno.com
>
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>Hi
>
>Look around carefully.  Some serial eeprom will take care of the
>"ringbuffer".  When you reach the end of memory it will start writing
>at
>the beginning.  I don't have any details but I think the 24LCXX and
>the
>rest of that family do it.  I have some 24C256 from Atmel and I think
>they do it too.  Look around and I'm sure you'll find the answer.  If
>you don't give me a shout and i will try to help.
>
>Charles
>
><SNIP!>
>
>with 256k memory.This EEPROM should function as a ringbuffer. The data
>from the serial port will be stored and when the memory is full,
>it should start overwrite the datas and so on. I will connect also a
>
><SNIP!>
>
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>

> Hi
>
> Look around carefully.  Some serial eeprom will take care of the
> "ringbuffer".  When you reach the end of memory it will start writing at
> the beginning.  I don't have any details but I think the 24LCXX and the
> rest of that family do it.  I have some 24C256 from Atmel and I think
> they do it too.  Look around and I'm sure you'll find the answer.  If
> you don't give me a shout and i will try to help.
>
> Charles
>
> <SNIP!>
>
> with 256k memory.This EEPROM should function as a ringbuffer. The data
> from the serial port will be stored and when the memory is full,
> it should start overwrite the datas and so on. I will connect also a
>
> <SNIP!>
>
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com

> On Mon, 16 Mar 1998 20:45:07 -0200 Thomas Fleckenstein
> <KILLspamrakelogthomasKILLspamVORTEX.IS> writes:
> [...]
> Not many people have answered this so here goes.
>
> >I need to know:
> >1. How does the IIC routine has to look like.
>
> For just controlling an EEPROM, you don't need a full IIC implementation.
>  The parts about multiple-master arbitration and the slave making the
> master wait by holding clock low don't apply.  The timing charts in the
> EEPROM data sheet are about all you need to know.  Since the SCL pin on
> an EEPROM is always an input, it's OK to just use a PIC pin always as an
> output to drive it.  But you do need a pull-up resistor on the SDA pin
> and be sure the PIC only drives it low when apropriate.
>
> >2. How can I design a ringbuffer with a eeprom connected via IIC bus.
>
> There's nothing too magic about this, just write bytes in sequence and
> wrap around at the end.  The problem is you also need to store pointers
> to the start and end of the data to find it again.  Storing the pointers
> in fixed locations in EEPROM will cause these locations to wear out much
> faster than the rest of the chip, since they are written every time data
> is stored.  If it's OK for the buffer to become empty when power is lost,
> just keep the pointers in PIC RAM.  When the power comes on again, set
> them to a "random" value so the first bytes in EEPROM aren't reused over
> and over again.
>
> I think a good way to keep the buffer state permanently would be to store
> special marker bytes or sequences of bytes (that are certain not to occur
> in the actual data) to indicate the start and end of the valid data.  To
> add data, the PIC would scan for the marker, overwrite it with new data,
> and write a new marker.  This way the wear on the EEPROM is better (more
> evenly) distributed.
>
> _____________________________________________________________________
> You don't need to buy Internet access to use free Internet e-mail.
> Get completely free e-mail from Juno at http://www.juno.com
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> Darwin Reynoso wrote:
> >
> > Hi,
> > any idea on how to store sound effects and voice
> > using an eeprom. thanks
>
> Go to the record store, and tell the manager "I've got a nice EEPROM
> here, and I'll trade you for a CD full of sound effects and voices"
>
> Seriously, you need to perform some sort of A/D conversion to obtain
> store-able data. The EEPROM isn't much involved in this process. Then
> once you have stored data, you'll need to convert it back to analog,
> with a D/A conversion. You can add compression to make better use of
> your storage, or encode delta-sigma, but all this happens outside the
> EEPROM.

>Hello,
>
>  I have a small question: What EXACTLY is the copyright and royalty
>status on I2C and SPI/Microwire ? There seem to be no direct web
>references, but ...
>
>  Who pays whom for what when and how, in 20 words, would be very nice to
>know imho.
>
>  There should be areason for many products using SPI and not I2C so far
>(especially if they do not originate in Europe), even if no Motorola
>chips are used in them at all.
>
>thank you in advance,
>
>        Peter

> Hi,
> I am trying to write and read eeprom 24C16. However it does not work.
> Did you ever did it ? I am using 16F84, 4MHz oscillator, SDA to RB7, SCL
> to RB6. Using Resistor pull-up to Vcc, 22k in, in SDA and SCL. I think
> the circuit is correct. I checked the voltage too.
>
> I followed the instruction in Application Notes AN567 and others,
> modified it to run at  16F84. I just write and read 1 byte. However, my
> 16F84 just read FF.
>
> Do you have any advises about it ? Is the algorithm wrong ? or Should I
> buy the new eeprom?
>
> Thanks a lot for your help.
>
> Regards,
> Harry
>
>

>
> Hi,
>
> the pull-up should not exceed 4k7, for high-speed connection even 1k.
> Regards,
> Imre
>
> On Fri, 22 Oct 1999, Harry Febianto wrote:
>
> > Hi,
> > I am trying to write and read eeprom 24C16. However it does not work.
> > Did you ever did it ? I am using 16F84, 4MHz oscillator, SDA to RB7, SCL
> > to RB6. Using Resistor pull-up to Vcc, 22k in, in SDA and SCL. I think
> > the circuit is correct. I checked the voltage too.
> >
> > I followed the instruction in Application Notes AN567 and others,
> > modified it to run at  16F84. I just write and read 1 byte. However, my
> > 16F84 just read FF.
> >
> > Do you have any advises about it ? Is the algorithm wrong ? or Should I
> > buy the new eeprom?
> >
> > Thanks a lot for your help.
> >
> > Regards,
> > Harry
> >
> >

>
> http://www.phanderson.com
>
> good luck
> Mike
>
> On Wed, 8 Dec 1999 20:23:04 +0000 Peter Keller <RemoveMEpkellerspam_OUTKILLspamDATALINK.CH> wrote:
> >Hi
> >I'm looking for C-code to read & write a 24LC64B EEPROM.
> >Any help ?
> >Peter Keller
> >
>
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