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Electronics => Electronics => Topic started by: polar bear6 on January 28, 2007, 05:01:34 PM

Title: EEPROM
Post by: polar bear6 on January 28, 2007, 05:01:34 PM

what exactly is an EEPROM?
is it just a chip that stores information?

Title: Re: EEPROM
Post by: Admin on January 28, 2007, 07:01:54 PM

Quote

is it just a chip that stores information?

yeap

if you really want the details:
http://en.wikipedia.org/wiki/EEPROM

Title: Re: EEPROM
Post by: Rand alThor on June 08, 2008, 05:59:41 PM

But an EEPROM chip is more than that. It stands for Electronically Erasable Programmable Read-Only Memory. You may have come across Random access Memory in your computer adventures, it's the memory that your computer uses to store and run the Operating System and programs in. ROM is read-only memory that stores boot-up info for the computer to use when it's just waking up.

Title: Re: EEPROM
Post by: bens on June 08, 2008, 06:12:47 PM

In the case of EEPROM, the "ROM" portion of the name is currently a misnomer that has stuck around from times when its ancestors really were read-only.  Modern EEPROM can definitely be rewritten.  The two main differences between EEPROM and RAM:

1) Writing to EEPROM is much, much slower than writing to RAM (maybe 3 - 4 ms for EEPROM vs nanoseconds for RAM)
2) EEPROM is non-volatile, so it persists even after power is turned off.

- Ben

Title: Re: EEPROM
Post by: Rand alThor on June 09, 2008, 12:09:35 AM

You're right, of course, bens. The whole name really is a contradictory statement. But I don't think that ROM chips are really the EEPROM's ancestors. I think of it more as a hybrid, like the situation of the rhombus, the rectangle, and the square in the middle.

Title: Re: EEPROM
Post by: pomprocker on June 09, 2008, 10:22:22 AM

here is a good list of memory

Volatile

    * DRAM, e.g. DDR SDRAM
    * SRAM
    * Upcoming
          o Z-RAM
          o TTRAM
    * Historical
          o Williams tube
          o Delay line memory

Non-volatile

    * ROM
          o PROM
          o EAROM
          o EPROM
          o EEPROM
    * Flash memory
    * Upcoming
          o FeRAM
          o MRAM
          o CBRAM
          o PRAM
          o SONOS
          o RRAM
          o Racetrack memory
          o NRAM
    * Historical
          o Drum memory
          o Magnetic core memory
          o Bubble memory
          o Twistor memory