Questions tagged [eeprom]

Acronym: Electrically Erasable, Programmable Read-Only Memory. Sometimes used with Flash parts that are similar to old EEPROM parts.

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38
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2answers
25k views

Why would one still use normal EEPROM instead of flash?

Is there any reason why people are still using (and implementing in new systems) normal EEPROMs instead of flash memory, nowadays? From the Flash memory wikipedia: Flash memory was developed from ...
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3answers
547 views

Storing An Led's Previous state when power is removed with eeprom now

A while ago I asked a question about having 2 push buttons, and an LED and you set the led to an on or off state with the two buttons, and then remove the power, and when turned back on, the led ...
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1answer
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Pointer Size using eeprom.h with ATmega328p in AVR-GCC

I am working on a project that randomly reads and writes large blocks of data from EEPROM, based on user input. I have used the EEPROM before, but I never really thought about this. In the operations ...
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1answer
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Bit Bang to I2C EEPROM MSP430

I found some code to Bit Bang to an EEPROM on the MSP430 here, but if I change the pins to what is on my design it fails to read and write. I've also added a LED for output this should blink if it ...
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7answers
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Alternatives to using EEPROM

As I understand it, EEPROM is a part of a computer (in my case, an AVR microcontroller) which stores data, and holds on to it even when the device completely shuts down. It allows data to be written ...
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1answer
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Replacing 27C256 with 28C256, how to wire /WE?

I am looking to replace a 27C256 compatible maskRom (nintendo Nrom PRG and CHR if it matters) with a socketed 28C256 in order to make a development cart. It looks like the pin for A14 is in the wrong ...
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2answers
2k views

Encrypt sensitive data in EEPROM

Let's say I have a PIC and an EEPROM memory IC. I store sensitive data in the EEPROM. If I want to encrypt the data what is a good encryption algorithm? It should be executed by the PIC but that does ...
0
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1answer
259 views

Ardupilot, atmega1280 and barometer

I'm working on a project and I need to know where the information taken by the barometer sensor are stored. I think in the eeprom, but exactly where? Is there a specific address or register memory? ...
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3answers
1k views

Connecting to an EEPROM

I am trying to download the contents of a ROM chip following this tutorial however the chip is surface mounted and I can't remove it to put it in a breadboard. I don't want to solder wires to the ...
3
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1answer
4k views

EEPROM or SD card storage for a general logger application?

If you need to store data, let's say numbers (one byte each), and you need a capacity for at least 100,000 readings in a low power sensor (3.3 V and less than 20 mA in stand-by operation), ...
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2answers
5k views

Difference between EEPROM types

I was wondering what the difference between EEPROM types are. For example 24S128 and 24LC128. My understanding is that typically the later digits, 128 in this case, represent the amount of space ...
7
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1answer
2k views

How does memory wear out?

I know that after time due to writing/re-writing memory wears out, and I was reading about a microcontroller from TI which uses "wear leveling" to insure the longest life of some EEPROM that the chip ...
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1answer
222 views

What does “full array operation” mean for EEPROM?

What is full array operation as shown in data sheet of AT24C08B: Two-wire Serial EEPROM (page3)? What is application of that full array operation? Please help to clarify.
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2answers
495 views

Device including RTC EEPROM and battery?

I am currently designing an electronic board and i got a question: Do you know if there is any device in which are integrated an RTC, an EEPROM and a battery? I heard about this type of device (i ...
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3answers
3k views

EEPROM read/write errors on dsPIC

I'm running a Microchip dsPIC30F6012a. I have this chip on several PCBs, all running the same software, and observe the same problem on all of them. This implies a systemic problem, not a one-off ...
4
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1answer
503 views

Can't read written data out of 24AA1025

I've got a PIC18F with MSSP that I'm interfacing with a 24AA1025. I'm using MPLAB 8 and the functions from C18 to make my life easier. The only problem is that I've (supposedly) written a byte to ...
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2answers
4k views

Unable to use compiler built-in functions to write to dsPIC EEPROM

As I mentioned here, I've been having issues with EEPROM on dsPIC30F6012A. Since my old EEPROM library was difficult to analyze and support, I went back to square one and rewrote it using the new (...
13
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3answers
17k views

I2C minimum clock speed and reliability

Is there a minimum clock rate specified by I2C? I know the most widely used clock rate is 100kHz and there is a "fast" mode of 400kHz supported by some devices, and a faster yet mode supported by ...
4
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1answer
1k views

EPROM Replacement Strategies

We have a system that uses OTP (one-time programmable) EPROMs, specifically the AT27C256. We would like to replace this EPROM with an EEPROM or Flash chip such that we can make our units field ...
6
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1answer
540 views

EEPROM: Same driver for similar chips, different behaviours

I have two very similar eeproms (M24C01-x and M24C64-x), both driven by the same standard library provided for my STM32F2. For the M24C64-x, all is fine. However, the M24C01-x is interpreting the ...
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2answers
2k views

EEPROM page size

I have an M24C01-x EEPROM (1 KBit in size) driven by an STM32. The datasheet doesn't make it clear what the page size of that EEPROM is. I require it to properly configure the STM32 EEPROM driver. ...
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5answers
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Frequent Write to Non-volatile Memory

I am designing a device that automatically adjusts it's physical position as temperature changes. If the device it shut off or power is disconnected the device needs to remember it's last temperature ...
0
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1answer
214 views

how to use TMP87P809N microcontroller with any EEPROM

How to use TMP87P809N with any EEPROM so that I can save timer counting of CMOS RAM in EEPROM for backup, I want to save that counting if electricity get failed and restart.
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2answers
925 views

Storing data to NVRAM

I'm designing an 8 bit computer, and one of the tricky parts is streamlining the loading of the small "OS" (read collection of routines) into the 32kB NVRAM that I will use instead of an EPROM. I was ...
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1answer
422 views

How to communicate with parallel eeprom with pic18f?

How to read eeprom M27C64A with pic18f4520, should i enable and disable the chip enable as well as output enable inside the loop while increasing the address? Can someone suggest me some code or ...
7
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3answers
6k views

100k EEPROM writes “per bit” or as a whole?

As I understand it, the life of an EEPROMs is usually rated at a certain number (e.g. 100k) of writes. Is this "per byte" or writes to the EEPROM system as a whole? E.g. If the EEPROM has 4k bytes, ...
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2answers
352 views

Changing the standard “message” on PIC24F shown on Android

I am working on an android accessory development. Currently whenever I plugin my Android device to the PIC24F (which I had programmed in the PIC24F) but I haven't installed in the Android phone It ...
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3answers
4k views

Reading empty (new) AT24C16 I2C EEPROM - 0xFF or 0x00?

What byte vaule should I see when reading empty EEPROM chip via I2C?
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2answers
1k views

How is this EEPROM fully addressable?

I am looking at the datasheet for this 64k EEPROM, and I am having trouble understanding how to use it. I would like to do a lookup from a 16-bit address to an 8-bit data word. The chip only has 13 ...
3
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3answers
2k views

How to program EEPROM

In looking for a 64K x 8 Parallel EEPROM, one of the most available chips is the 27SF512. Google would indicate this is commonly used by auto enthusiasts to replace chips in various cars. I have found ...
4
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2answers
3k views

Flash/EEPROM endurance

In this answer stevenvh suggests that Flash memory uses the same floating-gate technology as EEPROM. However! Looking at a random AVR datasheet it says for EEPROM 100 000 erase/write cycles, while for ...
3
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2answers
4k views

High capacity - EEPROM chip

I am looking for high capacity eeprom(I2C compatible) IC as an alternative to 1gb or 2gb micro SD card (data storage segment in my project) just in case I fail to interface Sdcard with pic32 mcu.. ...
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1answer
2k views

How do I read I2C memory with an Arduino?

I have HH100D humidity sensor. It outputs a frequency signal, which I know how to handle. However, it also has a small EEPROM with calibration values that is available via I2C. Those values are ...
4
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2answers
2k views

Will reading EE/E/PROM wear it out?

After reading some answers on SuperUser, I started thinking: Can EE/E/PROM be damaged by only reading it, with no writing at all? I've read several datasheets for EEPROMS and products that contain ...
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3answers
461 views

What's the difference between 24AA1025, 24FC1025 and 24LC1025

24AA1025: operates from 1.7V - 5.5V, 400kHz, $2.37 24FC1025: operates from 2.5V - 5.5V, 1 MHz, $2.37 24LC1025: operates from 2.5V - 5.5V, 400kHz, $2.37 See here. 24AA1025 is unique, because of the ...
4
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3answers
4k views

Failure mode of FLASH memory

What is the failure mode of flash memory? I've got some chips rated for 10,000 cycles - what happens after 10k cycles? Do the chips stop writing properly, do you get read errors, etc.? Does it also ...
4
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3answers
812 views

Intermittent SPI bus

I'm attempting to interface a PIC18F4520 to a 25LC640 via SPI protocol. I'm using the built in MSSP hardware of the PIC. The PIC18F4520 is the only master on the bus. I'm reading 16 bytes of data from ...
6
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2answers
1k views

Serial EEPROM with FAT

Is it possible to format an SPI EEPROM (such as AT24C128) to be used as an SD card? So format it with FAT 32 and have a 16MB drive appear in windows? Thanks
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5answers
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Memory suggestions for MSP430

I'm developing a measurement application with the TI MSP430 and I would like to hear some suggestions on what type of memory I can use. The idea is to use it for logging during a certain time and ...

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