What is an EPROM?
What is an EPROM?
EPROM or Erasable Programmable Read Only Memory is rewritable memory chip that may maintain its facts without strength. A programmed EPROM can maintain its facts for up to twenty years and can be examine indefinite range of times. An Israeli engineer, Dov Frohman invented the EPROM chip in 1971.
EPROM chips are embedded on an external programming tool earlier than getting used at the circuit board. The EPROM chip requires a high priced ceramic chip package deal with a small quartz window this is sheltered with opaque, sticky tape. For reprogramming, the chip is extracted from the circuit board, the tape is detached and it's far placed below a focused ultraviolet (UV) light of wavelength 235nm mild for approximately 20 minutes.
Some microcontrollers, earlier than the era of EEPROMs and flash reminiscence, used EPROM to keep their program. Such microcontrollers consist of some variations of the Intel 8048, and the "C" version of the PIC microcontroller. Similar to EPROM chips, such microcontrollers got here in windowed (high-priced) variations that have been on hand for debugging and application development. Leaving the die of one of these chip exposed to sunlight can trade its behavior in sudden methods.
EPROMs are available in numerous sizes in regards to both packaging and garage capacity. Parts of the same type of EPROM from distinct producers are intercompatible so long as they are most effective being examine, there are subtle variations within the programming procedure.
Most EPROMs may be diagnosed through the programmer by way of forcing 12V on pin A9 and reading the 2 bytes of data. However, programmer software could permit guide placing of the chip to ensure right programming.
EPROMs are the forerunners of the modern-day EEPROMs and flash memory.
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