Questions tagged [nand-flash]

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18
votes
2answers
3k views

Why are NOR flashes still used when NAND flashes have a bigger size?

I've seen a few systems that uses a NOR flash to boot from, and a NAND for a bigger filesystem. I've also seen a system with only NAND gets corrupted after files being written to and verified correct. ...
8
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1answer
2k views

Flash memory data retention time

I'd like to buy one of those after market Android car head/infotainment units. But I don't think there's a way to reinstall the system software if it gets corrupted, so I'm concerned about how long ...
6
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1answer
3k views

Why is NOR memory considered XIP, and NAND memory is not?

I've been reading up on NOR and NAND memories in search of an answer as to why exactly is NOR a XIP (eXecute In Place), and NAND is not. While both of the links were extremely informative and well-...
5
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2answers
4k views

eMMC vc MMC storage

I came across this new technology for storage and I am still a bit confused. What are the basic differences between MMC and eMMC storage? If a microcontroller is marketed as supporting SD/MMC, can I ...
5
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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 ...
5
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1answer
1k 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 ...
4
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1answer
6k views

eMMC interface : Parallel vs SDIO

I want to use an eMMC card for my application. After searching on different websites,I was not able to find any parallel interface supported eMMC chip. Is parallel interface available for eMMC chip? ...
2
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3answers
3k views

Does cooling the NAND chips on an SSD negatively affect its reliability?

The problem of heat dissipation in high-performance, small form-factor SSDs is well-known, for example, the paper Transient Thermal Analysis for M.2 SSD Thermal Throttling published in 2018 17th IEEE ...
2
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2answers
632 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
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1answer
842 views

"Stacked" NAND flash memory; 2 chips on a single circuit?

Sorry if this is a stupid question, I'm a newbie just getting into the actual hardware side of things. Obviously I'm starting small, just a simple re-balling of a BGA chip to build my own Single Board ...
2
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1answer
1k views

NAND Flash vs NAND EEPROM

I'm not clear how (if) NAND EEPROM (made by Toshiba) is different compared to regular NAND Flash memories (except is cheaper). We want to use with SAM9G device that is support NAND devices such as ...
2
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1answer
91 views

Desoldering CPU from PCB or holding it in reset

I am currently working with a NAND flash that I want to dump. The goal is to take a look at the data that is stored in the filesystem. To do so I soldered 8 wires to the NAND flash to access it while ...
2
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2answers
4k views

How is NAND Flash memory array organized?

Could you please explain how memory array organization calculated? Here I have attached snapshot of 2Gb NAND flash memory array organization. I can't understand the calculation of 1 Plane (marked in ...
2
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0answers
586 views

File system to use with NAND Flash and 32 bit microcontroller

I am searching for a file system, suitable for NAND flash memory chips. Currently I use a Micron 256MB SPI NAND flash memory where I write and read raw sensors data but without a file system and ...
2
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0answers
29 views

What are two typical threshold voltages for a flash FET?

I have a simple question for you all: what is a realistic approximation of a pair of threshold voltages for a flash transistor? I am working with NAND flash, 45nm, with VDD = 0.8V. I can find lots of ...
1
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2answers
858 views

How to secure an EMMC

My department of the company I am working at is in charge of developing a circuit for production, and security in the embedded system is a crucial requirement. The current prototype of our embedded ...
1
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1answer
866 views

Why is NAND flash slower than NOR when it comes to reading?

I have read on several places that NOR flash have lower latency when it comes to reading compared to NAND version but I don't understand is this architectural consequence or due to, often different, ...
1
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1answer
395 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
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2answers
99 views

Which MSC Sub Class is the best for USB 3.0?

I have been looking at implementing the Media Storage Class on a FX3 from Cypress. There is already a pre-written firmware example using MSC BOT (Bulk Only Transport) and SCSI commands and I was ...
1
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1answer
3k views

What type of FLASH (NAND or NOR) is used on microcontoller? [closed]

I am doing a study on file systems for mcirocontollers (MCU), using internal flash only. I find my self asking this questions: What type of FLASH memory is used most commonly in MCU ? NAND or NOR? ...
1
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1answer
506 views

Internal memory organization of Samsung NAND flash K9WAG08U1D

I am using samsung K9WAG08U1D NAND flash memory for storing logged data. Datasheet of K9WAG08U1D is shared for part numbers K9F4G08U0D K9K8G08U1D K9K8G08U0D I am trying to find difference between ...
1
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1answer
197 views

Offline (unpowered) storage time limit for NAND based drives? [closed]

What's the storage time limit for NAND based drives? Like Samsung EVO 850 or something similar? Also, since USB storage drives use NAND flash... what's the storage limit on them as well? When I ask ...
1
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1answer
147 views

NAND flash memory Organization issue

Organization Page size ×8: 18,592 bytes (16,384 + 2208 bytes) Block size: 1536 pages, (24,576K + 3312K bytes) Plane size: 4 planes × 548 blocks per plane Device size: 384Gb: 2192 blocks; ...
1
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1answer
627 views

Possible to replace worn out NAND chips in solid state drives?

I understand that SSD endurance is typically much greater than advertised and disregarding any form of data recovery, is it possible to replace NAND chips in solid state drives (with the exact same ...
1
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1answer
257 views

On NAND or NOR flash, is program time completely independent of byte values?

I know that the erase value of NAND and NOR cells is all 1s, and the process of programming involves clearing bits. Is the program time of some x length data always the same, regardless of the number ...
1
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1answer
649 views

Size of Samsung NAND Flash K9xxG08xxM

I am writing device driver for Samsung NAND flash K9xxG08xxM. I am not aware of exact part number as its staked board. But Device ID of flash is EC D5 51 A6 68 ...
1
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1answer
50 views

Calculating data retention rate of SLC NAND

Background I am a software developer trying to calculate data retention rate of a NAND memory ic. I have minimal knowledge/experience with electronics. I have a constraint on data retention, 15 years. ...
1
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0answers
211 views

Which pins are required when reading and writing NAND flash?

I plan on reading and probably writing NAND flash on some embedded devices or USB flash drives. I did not come across many examples for in circuit reading though I'd give that a try at first if ...
1
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0answers
332 views

invalid read data from nand flash

I want to use a nand flash ic with part number of K9F1G08U0C and connect it to a stm32f429igt6 microcontroller. Although I can read the ID of this nand successfully but the written data and read back,...
0
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3answers
238 views

RAM and Flash structure difference

I am trying to get a better understanding for RAM and Flash and I hope you could help me out with some things. What I know about Flash (or at least I think to know), is that there are different Flash ...
0
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2answers
222 views

Can I lower flash power consumption by pre-flashing all values to high?

I am designing an embedded system that will use either embedded flash memory or an SD card. The system must survive without much power and the estimated 30mA draw of an SD card sounds too high for me. ...
0
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3answers
807 views

Why NAND FLASH is slower than flip-flops?

I find that both NAND FLASH and flip-flops are made up of NAND gates. The only difference between them is NAND FLASH uses floating gate transistors to store charge. Your Flash drive is ...
0
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2answers
97 views

Is a NAND flash chip better for power saving purposes as a micro SD card?

I know, they are technically the same, but from what I read, NAND flash chips can be controlled better like putting it into standby and waking it up in the matter of a few nanoseconds, which could be ...
0
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1answer
269 views

Difference between 24 bit and 32 bit addressing mode in QSPI flash

I would like to know the difference between 24-bit and 32-bit QSPI flash? why 24-bit address is used in flash?
0
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1answer
61 views

Can't read an entire page at once (NAND flash)

I am working for quite a while now with a GD5F1GQ4UCYIG from GigaDevice. The goal is to dump the content of the flash. To do so I use a BusPirate. The NAND flash itself is still attached to the board,...
0
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1answer
159 views

NAND technology - ecc error

Nand technology has some issues, which I find it a bit difficult to understand. It is said in nand devices that manufacture guaranty that a page will have no more than X (4/8/16,etc according to nand ...
0
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1answer
83 views

SST 39VF1602 - NOR or NAND?

I have this flash chip, and I cannot figure out if it is a NOR or a NAND flash chip. Here is the datasheet. From the capacity of the chip (2M), I am assuming that it is a NOR chip, but I am not ...
0
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1answer
54 views

What exactly is meant by 'CompactFlash' in the context of flash memory?

I've been doing some inquiry about flash memory and I do know how flash memory works and I do know about the different layouts (nand/nor) and how the reading and writing processes function. My ...
0
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1answer
85 views

Why is erasing NAND much faster than erasing NOR flash?

Why is erasing of a single block in NAND flash usually much faster than erasing a single block in NOR flash? For my current understanding: If all cells of the block share the same substrate and if all ...
0
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1answer
48 views

User controlled storage devices existence

Today's memory devices have a lot of logic embedded before data is actually written onto the NAND pages. An example could be wear levelling algorithm , FTL functionalities etc. The typical life of a ...
0
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1answer
52 views

Are there ways/technologies to use High negative voltages in flash memories?

I am using an FGMOSFET with tunneling gate and control gate as an analog memory for simulation in SPICE. I use -25V to inject electrons into the floating gate and 25V to remove electrons. Everything ...
0
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1answer
1k views

What data is stored in an eeprom that’s not in the flash memory? [closed]

I’m wondering generally what information is stored in an eeprom that’s different than what’s in the flash drive that contains firmware? Mostly in mobile devices. Does the eeprom contain user settings ...
0
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1answer
3k views

How does NAND reading work?

Hi Now I'm trying to understand how does the NAND Flash reading work. AS I know, when the NAND FLASH reading work, the gate voltage go to 5v. then electrons flow depend on holes. then we can read ...
0
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1answer
130 views

May a warm reset by pulling down the reset pin of the SoC cause the file system corrupts?

In my embedded Linux system, I made a hardware switch to pull down the reset pin of the SoC(TI DM365). When the system is running, I can push the button to reboot the system. I want to know whether ...
0
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1answer
739 views

STM32F4 Mass Storage Device

I'm trying to build a msd with stm32f4 which will be connected to a pc with USB. I need to visualize it as "USB drive" formatted in FAT. Initially I was planning to use a nand flash but I can't use it ...
0
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1answer
189 views

Looking into NAND Flash memory

I'm looking into NAND Flash memory to use with my AVR MCU (Atmel Tiny85). I am particularly looking at the 8Gb Spansion S34ML08G101TFI200. I would like to sequentially read the entire contents of the ...
0
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1answer
23 views

How addresses are encoded in a Macronix MX35LF1GE4AB Nand flash memory chip?

I read the documentation for the Macronix MX35LF1GE4AB flash memory chip. And I attempt to implement a script that dumps its contents to a file. So I was reading the chip's documentation https://...
0
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0answers
90 views

Replacing SD card with Flash Memory Chip

I have a design in which MicroSD card is used for Logging and critical system information files. Logging: text file of few MB. Max 16MB. System Information: File format is xml and size is around 200KB....
0
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0answers
72 views

Why are Samsung NAND flash memory chips so hard to find?

I'm looking at NAND flash memory chips for a home project I'm working on. There seems to be quite a few manufacturers available, Micron seems a good choice (even though a lot of their chips, mostly ...
0
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0answers
46 views

Why it is required to write each byte with 0 before erase in NOR flash?

It is written in some sites that for NOR flash, each byte has to be written with 0 before erase. Why it is required to write with 0 before erasing? Erasing the sector change each byte to 1.