Re: PIC and EEPROM modules

On Jan 9, 2:17 pm, donald <Don...@xxxxxxxxxxxxxxxx> wrote:
coetzee.ev...@xxxxxxxxx wrote:
Hi guys

I'm currently using a PIC16F84 for a project. I need to use more
EEPROM than I have on the chip. So I'm considering adding a memory
module to store the additional data. I have no idea what my options
are, which will be the easiest to implement etc.

I dont even need the PIC to write the data to the EEPROM. I would like
to use my computer to program the EEPROM (max 1Mb) and then just use
the PIC to read it (I do the same currently with the PIC. Write EEPROM
data with the pic programmer and then read the data with the PIC).

I've been to microchip's website but I don't really get a noobguide to
what my choices are. Seems like there's at least two architechtures
I2C and SPI. Which will be best? Any suggestions?

Thanks

Some design considerations.

How many pins do you have left on the16F84 ?

How much code space do you have left in the16F84 ?

The16F84 does _not_ have an SPI or I2C controller on board.
You will need to bit-bang the lines to the external EEPROM.

With these assumption, what can you do with your design ?

Also, getting any data from your PC into the EEPROM.
Do you have an external programmer, do you want to code another PIC to
interface to a serial/parallel port on your PC.

Do you want to remove the EEPROM from the target board to reprogram it ?

All these things can be done, you need to make a decision about what you
want to do.

One last thing, are you programming in assembly or C ?

donald

Hi

I really have a quite simple program. So I'm flexible on changing pics
etc. I need to do something like a clock which plays a different tune
every 15 minutes. The tunes are stored in the memory. So I want to use
a computer to program the tunes into the memory module. If that
doesn't work I'm willing to program another chip to program the
memory, but I'd prefer to use the PC straight on the memory module. I
use a K149 USB hardware pic programmer. I use assembly (trying to keep
it elementary). I'm more than willing to remove the EEPROM to
reprogram.

BTW: I know the DE command to program pic EEPROM from the PC. Can I
somehow program the pic memory RAM that way as well? It's REALLY
difficult to search in google for DE, DT and other 2character
commands. Does anyone have a link of how to program pic memory RAM (in
a similar way that you program EEPROM on the pic)

Thanks!
.

Relevant Pages

  • Re: Memory selection for an embedded system
    ... and high density per dollar, but it requires a refresh circuit which ... one device, which for most embedded systems, unless you call pentium ... often times used as ROM while EEPROM is ... The choice of which type of memory you select depends on the goal of ...
    (comp.arch.embedded)
  • Re: Datalogger with Flash
    ... the begining of the memory, and thats ok with the eeprom, but with the ... the message that im writing its 16 Bytes Long. ... If your moving up to a flash part, ... You are already over writting 16 bytes in a full eeprom. ...
    (comp.arch.embedded)
  • Re: PIC and EEPROM modules
    ... EEPROM than I have on the chip. ... I dont even need the PIC to write the data to the EEPROM. ... The tunes are stored in the memory. ...
    (sci.electronics.design)
  • Re: understanding MCUs: Flash vs. SRAM
    ... kinds of memory. ... Most kinds of flash memory ... EEPROM is, but I don't know how an MCU would make use of it. ... microcontrollers are on internal RAM. ...
    (comp.robotics.misc)
  • EEPROM or NVSRAM
    ... an outboard serial EEPROM. ... (which is a FANTASTIC holder for this battery! ... memory dumps when replacing the cell. ... The application will be inside a work truck, permanently attached, so ...
    (sci.electronics.design)