Questions tagged [non-volatile-memory]

Memory which maintains it's value through power cycles.

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31
votes
3answers
9k views

What's the catch with FRAM?

After recently acquiring an MSP430 Launchpad I've been playing with various microcontroller projects. Unfortunately, the MSP430G2553 only has 512 bytes of RAM, so doing anything complex requires ...
21
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4answers
3k views

Why are SRAM based FPGA used more than NVM based FPGA?

SRAM based FPGAs need to load the bitstream again after power off. Meanwhile the Non-Volatile based one don't need that. I wonder, why are more experiments and security research done on the SRAM ...
14
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4answers
6k views

Why do most of the non-volatile memories have logical 1 as the default state?

I have used non volatile memory, like EEPROM and FLASH memory, in embedded applications and I have always found that unused memory (EEPROM/FLASH) bit locations are always set to ...
13
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4answers
10k views

Does a USB mouse have memory that could be used to store malware?

I worry that this might get flagged as too broad, but here it goes: Lately I've been thinking about the possibility of loading data on peripheral devices. One of the most used peripherals is the ...
12
votes
7answers
3k views

Need a non-volatile memory IC with near unlimited read/write operations capability

I need a memory solution which is going to be used to keep track of an accumulated count on a micro-controller based project. By accumulated count, I mean to say that the micro-controller uses this ...
11
votes
7answers
14k views

I2C slave address not acknowledged (sometimes)

I'm trying to communicate with a remotely connected FRAM (FM24C04 from Ramtron) by using I2C. This memory is embedded on a board that can be inserted and removed at any time to/from the system (...
10
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3answers
4k views

Why must flash memory be written/erased in pages/blocks?

Title says it all. I'm trying to understand the workings of flash memory technologies, at the transistor level. After quite some research, I got good intuitions about floating-gate transistors, and ...
9
votes
7answers
3k views

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 ...
9
votes
1answer
1k views

How is a DRAM volatile with capacitors?

There are a few things I understand: DRAM stores each bit of data to a tiny capacitor with some potential difference. Unless the capacitor is connected to low voltage end, the potential difference ...
9
votes
5answers
2k views

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 ...
5
votes
4answers
2k views

Memory capability and powers of 2

Why are computer memory capabilities often multiples of a power of two, such as 2^10 = 1024 bytes? I think it is something related to the binary logic, but I do not understand the precise reason for ...
5
votes
3answers
1k views

Why isn't there any EEPROM in STM32F4 MCUs? [closed]

Why isn't there any EEPROM in the STM32F4 series MCUs? Mostly I have Microchip MCUs and they have EEPROM available in them, but I just found out that it is not available in the STM32F4 MCUs... And it ...
5
votes
2answers
4k views

How to store audio data for AVR project?

I see a lot of projects for AVR-based audio players that use an SD card to store the audio data. In fact, I am currently doing the very same thing on an Arduino and its Wave Shield, which has an SD ...
5
votes
2answers
1k views

Will reading serial flash memory wear it out?

I know that a flash memory has limited write cycles. Does it also have limited read cycles? Datasheets of most serial flash memories (like SST25VF series) mention endurance cycles. Does this ...
5
votes
1answer
2k views

Why can't NAND flash memory be a random access memory?

When I read any documents regarding NAND and NOR flashes. They say that NAND is sequential memory whereas NOR is random. I dont understand what stops NAND memory from being random too as the only ...
4
votes
3answers
546 views

What sort of a ferrite core will I need to make core memory?

I am building a homebrew computer using core memory. What sort of a ferrite core will I need?
4
votes
2answers
13k views

How long until my eMMC is dead?

I got some feedback from our software team. Apparently we're writing twenty 4KB blocks per second. I have a 4GB eMMC. The eMMC has a max number of P/E cycle of 3000. I'm making the assumption that ...
4
votes
1answer
720 views

Read and Write multi variable (Struct) from/to external FRAM memory over SPI by ATMEGA Using Code Vision

I am working on a project to read some data from ADC and store them in external FRAM over SPI. I have 8 different float values which need to save when the power is off or other specific situation and ...
4
votes
2answers
2k views

EEPROM Write Cycle Time and Write Cycle Endurance

I have an embedded software application that is copying a buffer from RAM to EEPROM. In this case, the EPROM device is a 28C010 (128K x 8). The copying is done at non-regular intervals, generally in ...
3
votes
3answers
2k views

Serial NOR Flash - Vague

What are the structural differences between Serial NOR Flash and Parallel NOR Flash? If there is a structural difference , then What are the differences between Serial NOR Flash and Serial NAND Flash? ...
3
votes
1answer
15k views

Storing settings/data on microcontrollers non-volatile memory (STM32F103)

I want to be able to store values in a non-volatile memory so that the microcontroller can load these settings at start up. These settings might change at run-time and it is important for the systems ...
3
votes
2answers
344 views

How does the Pre-charge and Equalizing circuit shown in the below figure work?

(from precharge circuit) Could you please explain the operation of the above circuit regarding how the transistors Q8 and Q9 are responsible for charging the Bit Lines with VDD/2 while Q7 equalizes ...
3
votes
1answer
521 views

Is it possible to read erased flash memory?

In hard disks, a "quick format" does nothing to the actual data on the disk - just clears the FAT (file allocation table), which then appears as a "blank disk" to the user. Therefore, it is fairly ...
3
votes
1answer
657 views

FPGA Configuration Flash as General Purpose Memory After Boot

I am currently working on a system with a Spartan-6 FPGA and have a need for some low volumes of non-volatile memory to be used during system operation. My question is, since I have a relatively ...
3
votes
3answers
16k views

STM32 SPI Peripheral bug?

I'm using STM32F051R8T6 on STM32F0-Discovery board and M25P80 flash IC as a peripheral. I've got the SPI configured in 3-line (+ 1 software chip select line), full-duplex mode and I'm using polling to ...
2
votes
2answers
1k views

FPGA non-volatile progamming

I recently bought a Cyclone II FPGA here. I have been able to program it with a USB Blaster cable and the Altera Quartus Software. The problem is that when I disconnect power, I lose the program. ...
2
votes
2answers
535 views

Why fram instead of eeprom

Why do all the gameboy cartridge mods for nonvolatile save use a type of ram like fram? Why isn't a sufficiently fast eeprom or flash ic used? EDIT: We all know this is about parallel interface ICs, ...
2
votes
2answers
5k views

Differences, uses, and theory of volatile and nonvolatile memory?

I understand the basics of volatile and nonvolatile memory. Volatile memory requires a constant power supply to retain data whereas non-volatile memory does not require a constant power supply to ...
2
votes
2answers
665 views

Flash memory slower than magnetic disk [closed]

If flash memory is slower than magnetic disk, how can SSDs be faster than magnetic HDDs? Flash memory (such as USB thumb drives) is a specific type of EEPROM, used for small portable disk drives. ...
2
votes
2answers
506 views

How does triple level cell FLASH memory achieve 3 bits per cell?

Originally each cell of FLASH memory held either a high or low level or state, and reflected one bit of information; 0 or 1. Mutli-level FLASH was then developed, with often four levels of voltage ...
2
votes
2answers
191 views

Non-Volatile Serial Memory Chip

I need a non-voltile serial memory chip that I can clock random bits(about 500 bits) into one at a time by hand using toggle switch to clock them in . This stored bitstream is then clocked out at 20K ...
2
votes
1answer
188 views

Floating Vdd; NV Pokemon saves [closed]

http://forums.benheck.com/viewtopic.php?f=18&t=38664 In the link, there is a thread discussing replacing gen 1&2 Pokemon cart sram ICs with fram equivalents. The only differences between old ...
2
votes
1answer
269 views

EEPROM Write Limit [duplicate]

Just curious as to why do non volatile memories like EEPROM in an AVR have a write limit ? Also is this limit per location/adress in the memory or on the memory as a whole ?
2
votes
2answers
268 views

High capacity flash memory

I'm trying to find a suitable high capacity (4-16GB) memory for an embedded application. Clearly this is going to be some kind of NAND flash memory. I need to be able to write to it at at least 16....
2
votes
2answers
76 views

Preserving state of variables in RAM on Power Failure

I'm developing a code with Nuc240(ARM Cortex M0) Microcontroller. Where I need to store the value in some of the variables to the Internal Data Flash. I use ISP procedure for this, but i have seen the ...
2
votes
1answer
862 views

Some general NAND flash questions

I have some questions about nand memories. Do we need to erase whole block to rewrite only one page? If true, what is the algorithm? Cache whole block > edit one page > erase whole block > write ...
2
votes
1answer
946 views

AVR program code location

I'm working with an ATmega328P and I wanted to interface with the flash memory writing data to it with the macros provided by avr-libc. This is the memory map for my chip: ATmega memory map http://...
2
votes
0answers
1k views

STM32 Flash acting like RAM

I've been trying to program a word of flash memory on my STM32F030F4, but for some reason whenever I power it off and on again, the memory location has defaulted to '0xFFFFFFFF' again. Am I missing ...
1
vote
3answers
2k views

Why use RAM IC over EEPROM IC?

I have been looking at various different external storage ICs that would work with an arduino. When I looked at the specs of some EEPROM chips and compared it to the specs of other RAM chips, I ...
1
vote
4answers
124 views

Volatile keyword with ADC, USB interrupt readings

I was just reading an answer about global variables, it also stated that I should use volatile affix whenever a global is used in an interrupt. In my program I am using a 30 byte ADC buffer without ...
1
vote
2answers
691 views

Easy way to tell if a low power MCU supports external memory?

Please forgive my ignorance, as am very new to this. I am looking to build a custom PCB and have found several low-power modules with internal MCUs. Is there an easy/quick way to determine whether ...
1
vote
2answers
3k views

How does an SD card communicate with a computer? [closed]

Could someone please give me a concise explanation to how an SD card sends and receives data from a computer. Does it do this one bit at a time? How does the computer/SD card combine these individual ...
1
vote
2answers
83 views

Adapting an I2C FRAM chip to an SRAM-like parallel interface

I have a project that requires a parallel interface non-volatile RAM. I had hoped to use an FRAM, however the only parallel FRAMs seem to much larger in capacity (and more importantly, price) than I ...
1
vote
1answer
261 views

Are EEPROM chips getting obsolete?

I am making a circuit with a microcontroller that has a periodic need to save about 500 bytes of information in a non-volatile storage. Running only on a supercap that might be charged up rarely, the ...
1
vote
2answers
83 views

I've seen many conflicting answers online: For optical storage, does a pit represent a '1' bit or does a land represent a '1' bit?

I've seen many conflicting answers online so: When reading an optical disk, which one of these is true: A 'pit' represents 1 and a 'land' represents 0 or A 'pit' represents 0 and a 'land' ...
1
vote
1answer
144 views

Memory dump size does not match size of MTD partition

Device with Linux embedded system on NAND flash memory. I did memory dump of some MTD devices partitions use serial console, from U-boot bootloader use available commands. First I read MTD partition ...
1
vote
2answers
354 views

How, could hardware write protect be implemented for flash media?

I come from a software background, but feel this is a hardware/electronics question. Looking for a way to hardware-write-protect on flash media, I bought an SDHC card (with a tiny switch labelled "...
1
vote
1answer
719 views

Where to store non-volitile variables on ARM microcontroller

Noob question here. I have only a little experience with microcontrollers and all that experience was limited to the 8051. I am working on a project and would like to use the ARM cortex M4 ...
1
vote
1answer
117 views

How do simple low power devices store setup when switched off?

I often come across battery powered items that store their state when switched off, particularly 'simple' items like LED bicycle lights (e.g. flash or solid light, changing each time it is switched on)...
1
vote
1answer
67 views

NVSRAM - Storage Capacitor Selection

I was reading this document from cypress website on Various storage capacitor options for nvSRAM. In page 2 , under the heading 'key characteristics' (see link below), I came across various values for ...