# Why do I need to read/write from/to EEPROM in embedded applications? [closed]

What is the usage of the EEPROM in embedded application? can you give me examples?

## closed as too broad by Chris Stratton, Elliot Alderson, RoyC, Nick Alexeev♦Oct 1 '18 at 2:05

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• What is the usage of long-term memory in your brain? Can you give me examples? – Harry Svensson Sep 29 '18 at 8:43
• Is this homework? – Transistor Sep 29 '18 at 8:44
• i am just trying to clarify the subject in my mind. And this is not my homework. I am studying on a book about microcontrollers and microprocessors, i read about memory devices, rom prom eprom eeprom. and i am wondering, these are not much memory blocks. what is the usage what can we do with them? is it a problem that i am asking about it? – user198690 Sep 29 '18 at 8:47
• Look at the (consumer) products around you, like TV, (car) radio, thermostat, (alarm) clock, keyfob, etc. Would you be happy if removng power/batteries restored them to their production (or pre-configuration!) state? – Wouter van Ooijen Sep 29 '18 at 8:49
• EEPROMs (or devices like them) perform important duties in CPU-based devices. As said before, a basic Internet search should yield plenty of explanations. Compare EEPROM with PROM, ROM, UV-EPROM and Flash memories. If you have a specific question, please ask it. – mike65535 Sep 29 '18 at 9:56

As noted in the comments my answer to EEPROM is a Read Only Memory so why can I write to it? provides some relevant information.

Table 1. Summary of memory type features.

        WRITEABLE   ERASABLE   RETENTIVE  Notes
=====================================================================
RAM     Yes        Yes         No      Data loss on power cycle.
ROM  At factory    No          Yes     Data designed in.
PROM     Yes        No          Yes     Data user programmable.
EPROM     Yes        With UV     Yes     Wipe contents with UV light.
EEPROM     Yes        Yes         Yes     Change data while running.


The main benefit of EEPROM is that it is writeable like RAM (but much more slowly) but unlike RAM the data will survive a power cycle. It's typically used to store configuration settings or data that should survive a power cycle. Examples include devices such as a printer where parameters such as IP address, paper size, etc. and data such as total page count need to be restored on power-up.