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What is a PEROM ?
I saw these mentioned online somewhere and wondered what this kinda chip is
? Is it in the same family as EPROM EEPROM, etc ? Chris |
#2
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What is a PEROM ?
Skeleton Man wrote:
I saw these mentioned online somewhere and wondered what this kinda chip is ? Is it in the same family as EPROM EEPROM, etc ? Chris These are the types I'm familiar with. 1) Mask ROM. These are used for permanent read-only memory. There is a one time fee, to make the mask for the ROMs. Typically, you might do this, if you needed 100,000 identical devices, like firmware for something. For smaller production runs, use something else. 2) Fuseable ROM. Its been many years since I used these. These can be programmed once, and use something like Titanium-Tungsten. In the lab, I burned up $3000 worth of these, while doing product development. Great fun when the boss finds out. They're not reprogrammable. Now starts the devices based on Flash technologies. 3) OTP - this would be a flash memory which is one time programmable. It would allow, for example, a custom serial number to be placed in each component, as well as, say, some firmware. These might be used for the SPD chip on memory DIMMs, as an example. No erase options available. 4) EPROM - eraseable programmable read only memory. By means of a UV window and a UV light source, the device can be erased and returned to the all 1's state. More common in the 32 pin DIP era. Many happy hours spent with the UV light and trays of chips. 5) EEPROM - electrical eraseable EPROM. No window on this one, it can be erased electrically, with the right voltage applied. These would be used on motherboards. Your "PEROM" appears to be another way of stating (4). Until you mentioned it, I didn't even know anyone was using a term like that. It's always been "EPROMs" with my friends. Both (4) and (5) have limits to the number of write/erase cycles. HTH, Paul |
#3
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What is a PEROM ?
Skeleton Man wrote:
I saw these mentioned online somewhere and wondered what this kinda chip is ? Is it in the same family as EPROM EEPROM, etc ? Chris A PEROM is a dyslexic EPROM -- it automatically applies random transpositions to the data stored in it. ;-0 -- John McGaw [Knoxville, TN, USA] http://johnmcgaw.com |
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