Talk:EPROM
From Wikipedia, the free encyclopedia
Is the table in this article up to date? I can't believe the largest EPROM is only 512kb. sjorford →•← 10:02, 21 Mar 2005 (UTC)
- The table isn't really inclusive. It only lists one family of devices. There are larger ones, but I've never heard of one > 20 megs. Certainly, the common ones are all pretty small. - Bryce —Preceding unsigned comment added by 66.81.40.136 (talk • contribs)
Contents |
[edit] First EPROM
The first EPROM was the 1702 (256x8 = 2k memory) used to store the firmware or boostrap of the first microcomputers or programmable calculators. —Preceding unsigned comment added by Cl barbot (talk • contribs)
[edit] how does it work
How does an EPROM work? I think that there is missing that part. Explanation of EPROM memory cell work.--Čikić Dragan 16:28, 2 February 2006 (UTC)
- I don't know the details but i belive there is a "floating gate" on the transistors which can be charged using a higher voltage than that used for normal operation and discharged using UV light. Plugwash 01:26, 8 July 2006 (UTC)
[edit] Erasure
It says it can be programmed electrically, but can only be erased by UV light. Does that mean that once the chip has been programmed, you are unable to overwrite the settings with electrical signals? Does the chip need to be erased via UV light to change any programming?
- Yes, EEPROMS are the only ones that can be erased electrically —Preceding unsigned comment added by 67.177.254.247 (talk • contribs)
-
- Not quite, when erased an EPROM will go into a blank state (all zeros or all ones depending on its design), you can then electrically flip bits out of the blank state but you can't flip them back again. Plugwash 01:28, 8 July 2006 (UTC)
[edit] Electrically programmable rom?
Please note this: I read in some books that EPROM means Electrically Programmable ROM, and not Eraseable Programmable ROM. If other users confirm this, please correct the article. —Preceding unsigned comment added by 151.56.233.30 (talk • contribs)
- which books? i've certainly never seen this before and proms are also programmed electrically. Plugwash 01:17, 8 July 2006 (UTC)
[edit] What does the UV actually do?
I understand the basics of the programming side, the floating gate, but how exactly does the UV erase the data? Maury 12:16, 1 August 2006 (UTC)
[edit] Re-programmable EPROM?
Can I reprogram the EPROM after erasing it or how many time could I reprogram it?
[edit] data table submission from anon editor
the following was tacked on to the end of the article outside of the rest..
programming. klu EPROM Type Size — bits Size — bytes Length (hex) Last address (hex) 1702, 1702A 2 Kbit 256 100 000FF 2704 4 Kbit 512 200 001FF 2708 8 Kbit 1 KB 400 003FF 2716, 27C16 16 Kbit 2 KB 800 007FF KKESIT 2732, 27C32 32 Kbit 4 KB 1000 00FFF 2764, 27C64 64 Kbit 8 KB 2000 01FFF 27128, 27C128 128 Kbit 16 KB 4000 03FFF 27256, 27C256 256 Kbit 32 KB 8000 07FFF 27512, 27C512 512 Kbit 64 KB 10000 0FFFF 27C010, 27C100 1 Mbit 128 KB 20000 1FFFF 27C020 2 Mbit 256 KB 40000 3FFFF 27C040 4 Mbit 512 KB 80000 7FFFF 27C080 8 Mbit 1 MB 100000 FFFFF
If I stick it into a wikitable it looks like this:
| EPROM Type | Size — bits | Size — bytes | Length (hex) | Last address (hex) |
|---|---|---|---|---|
| 1702, 1702A | 2 Kbit | 256 | 100 | 000FF |
| 2704 | 4 Kbit | 512 | 200 | 001FF |
| 2708 | 8 Kbit | 1 KB | 400 | 003FF |
| 2716, 27C16 | 16 Kbit | 2 KB | 800 | 007FF |
| 2732, 27C32 | 32 Kbit | 4 KB | 1000 | 00FFF |
| 2764, 27C64 | 64 Kbit | 8 KB | 2000 | 01FFF |
| 27128, 27C128 | 128 Kbit | 16 KB | 4000 | 03FFF |
| 27256, 27C256 | 256 Kbit | 32 KB | 8000 | 07FFF |
| 27512, 27C512 | 512 Kbit | 64 KB | 10000 | 0FFFF |
| 27C010, 27C100 | 1 Mbit | 128 KB | 20000 | 1FFFF |
| 27C020 | 2 Mbit | 256 KB | 40000 | 3FFFF |
| 27C040 | 4 Mbit | 512 KB | 80000 | 7FFFF |
| 27C080 | 8 Mbit | 1 MB | 100000 | FFFFF |
I have no idea where this should go in the article. DMahalko (talk) 01:34, 31 March 2009 (UTC)
