Questions tagged [flash-memories]

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18
votes
9answers
7k views

Why is every address in a micro-controller only 8 bits in size?

I have seen that, in 32-bit microcontroller, each address of memory holds only 8 bits of data; it is the same for a 16 bit MC as well. For 32-bit data, it uses a combination of 4 addresses. Why can't ...
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. ...
13
votes
11answers
13k views

How to make 1 bit permanent memory circuit?

I would like to make a simple circuit to store or save 1 bit of data. The circuit should be able to remember the state of an LED ( on or off ) even if the supply is disconnected from the circuit. I ...
10
votes
1answer
620 views

Can you program a surface mount IC with flash memory and then reflow solder them?

I know that many chips, such as the ATMEGA328P-AU list flash storage lifetimes at certain temperatures, but they usually cap out at 100° C. I know that, ideally, one should include leads on their ...
8
votes
1answer
1k 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
votes
5answers
12k views

where are constant variables stored in microcontroller?

As per the memory layout of C program ,constant variables are stored in the Initialized data segment of the RAM. But as per some of the Microcontroller memory layout ,const variables are stored in ...
6
votes
1answer
5k views

Open Source USB Flash Drive Circuit Anywhere? [closed]

I would like to make a removable USB flash drive from scratch. I would probably start from component selection. And because this is not as exciting as some other DIY projects, I haven't found any ...
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 ...
4
votes
2answers
3k views

LTDC data starvation during simultaneous SD-RAM and NOR Flash access with STM32F429 rev 3

Application details: SDRAM is used as the LCD frame buffer. Memory for 2 LCD frame buffers are allocated(double buffering) in SDRAM. LTDC will be always accessing one of the frame buffer in the ...
3
votes
2answers
3k views

What does “32KB (16K x 16)” mean? [duplicate]

On digikey site program memory for ATMEGA328P-AU-ND is shown as 32KB (16K x 16). in ATMEGA328P datasheet program memory is 32KB but what does (16K x 16) mean? Other Examples are : 16K x 8 64 x 16 ...
3
votes
2answers
4k views

SD card detect in SPI mode

Just wondering if it is possible to detect the presence of an SD card when it is being used in SPI Mode? It would appear that the card detect/data 3 pin (CD/DAT3) is used as a chip select (CS) pin ...
3
votes
1answer
8k views

Can´t erase data from flash memory (STM32)

I´m trying to save some data to flash memory on my STM32F407 board. Before I can save them, I need to erase a memory sector. I chose 16 Kbytes Sector1 starting with address 0x08004000 and chose ...
3
votes
1answer
100 views

How many times can flash be rewritten before an erase is required?

With flash memory, it's only possible to write by clearing bits from their erased (set) state, and the only way to set a bit is to erase the region containing it. If you only need to clear bits, then ...
2
votes
2answers
675 views

Is this SPI Flash?

I'm currently reversing a device that has a chip soldered I can't identify. It's next to its controller, and judging from its size and position, it could be SPI Flash. It's SOP-8. Does someone know ...
2
votes
2answers
166 views

What are the purpose of voltage doublers in flash memories?

I'm wondering what is the need for charge pumps in flash memories.
2
votes
2answers
571 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
2k views

OTA Programming of STM32

I am currently using ST32L152RE controller interfaced with BLE CC2640R2F module and 4 MB external flash memory interfaced through spi. I was trying to upgrade the firmware of my st controller using ...
2
votes
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 ...
1
vote
4answers
3k views

Is flash memory in MCU's similar to a hard disk?

I have taken a Computer Architecture course in the past that focuses on desktop CPU's and I currently work in embedded systems and I am kind of confused as to which memory corresponds to what. I am ...
1
vote
2answers
213 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. ...
1
vote
1answer
85 views

How many excess electrons are in a modern SLC flash memory cell?

A colleague told me that in a modern SLC flash memory cell there are about 400 electrons. However, I can't find any reference to this. Flash memory cells can be thought of as little buckets of ...
1
vote
2answers
594 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
vote
1answer
2k 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
vote
2answers
2k views

MMC/eMMC Boot sequence

I've been trying to hook up an eMMC chip to a FPGA, that receives commands via a micro-controller to initialize and trigger write/read operations on given sectors. I'm having trouble with the boot ...
1
vote
1answer
186 views

Calculation of Power Dissipation of Memory ICs and Microcontrollers

Can someone tell me how to calculate the power dissipation of digital ICs like Nand Flash, QSPI NOR Flash and Microcontrollers? For Microcontrollers, we can get the power dissipation for GPIO like, ...
1
vote
1answer
143 views

Configuration settings for programming flash memory

I need to specify a memory addresses settings in the configuration file for programming flash memory with Macraigor Flash programmer utility. The device is BCM3360 (MIPS32) chip and flash memory is ...
1
vote
1answer
702 views

Is it necessary to write all MSP430 FLASH writing code should be run from RAM?

I am writing some device parameters to non volatile flash memory of msp430f2619 controller. Sample code shows that function writing to flash should be copied to RAM in initialization section. But I ...
1
vote
1answer
196 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
vote
2answers
424 views

What operations on flash(NOR/NAND) effect Flash Program/Erase(P/E) cycles

I want to implement a counter which can save values through power cycles, so I should use flash memory(I have option to choose NOR or NAND) but as my counter values will be increased frequently. I ...
1
vote
2answers
477 views

What is this type of write-protection called?

Upon powering up, flash memory is read/write. At some point during the startup phase, the firmware, the bootloader, or maybe even the kernel triggers some mechanism built into the flash chip that ...
1
vote
0answers
131 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
vote
0answers
184 views

Flash memory programming failure

I'm working on an XScale PXA270 with NOR Flash on Chip select 0. Due to the obsolescence of the previous flash, my company changed it for an AMD/Spansion compatible MX29GL128. I'm trying to write on ...
1
vote
0answers
1k views

Does NOR flash have better life span than NAND?

I wanted to know which one has better life span, NAND or NOR flash and what is the reason? By life span I mean the number of erase cycles allowed per block. I read in the link https://en.wikipedia....
1
vote
0answers
162 views

Problems programming a 29GL256

I've been experimenting with Python scripts and using an Teensy 2.0 ++ to program different flash memories. So far I've found a script to program a 29GL128, which works perfectly, but I'm trying to ...
0
votes
3answers
619 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
votes
1answer
37 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
votes
1answer
99 views

Finding Rise time and Fall time with Slew Rate Specification

I am using this QSPI Flash Memory IC I'm operating the QSPI clock at 48MHz. I am probing the Clock and Data signals in my scope. On Table 54 which is on Page 128, we have Rise time and fall time ...
0
votes
1answer
52 views

Writing on one flash memory location could affect whole memory page

I am working on designing energy meter using PIC18F46K80. When the power goes off the meter store data on the flash memory (credit and so). Meter power supply stores enough energy to supply the ...
0
votes
2answers
77 views

Reading current memory image from a micro controller

I have the MPLAB XPress Evaluation Board, which has the PIC16F18855 microcontroller on it. The way to program it is just to copy a ...
0
votes
2answers
135 views

Does the logic inside flash memory devices require a power down after each WRITE operation? [closed]

Does the logic inside flash memory devices require a power down after each WRITE operation? I was confused when reading the datasheet of the Micron Serial NOR Flash Memory. There is "To avoid data ...
0
votes
3answers
141 views

W25Q80: Data Loss

Today I've faced a strange problem: I have an LCD monitor controller board. It has an LCD panel driver chip having a 8051-based MCU inside, but the chip needs an external W25Q80 SPI flash for ...
0
votes
1answer
72 views

Similarities between flash memory and a camera flash?

This story is repeated in a number of places. What about flash memory would have reminded him of a camera flash? The name “flash” was suggested by Dr. Masuoka's colleague, Mr. Shoji Ariizumi, ...
0
votes
1answer
779 views

STM32F103 SPI MISO doesn't work as expected

In one of my small projects I use STMF103C8T6 as MCU and SPI memory W25Q128 of Winbond to store a data. The memory chip connected to SPI1. Here is a part of the scheme: The code is mostly generated ...
0
votes
1answer
227 views

How to work with eMMC from software developer point of view

I am facing a problem how to implement parameters management in an embedded software. Parameters management means that I have some subset of variables which values should be persistent but they will ...
0
votes
2answers
767 views

How to store 8 bit character in 32 bit Data Flash memory?

Is it possible to store 8 bit character to 32 bit Internal Data Flash in the Microcontroller by just using only 8 bit of space for each bytes?,by using a combination of 4 bytes which can be also ...
0
votes
1answer
49 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
votes
1answer
37 views

Built in Self Test - In Embedded memories

I am reading this thing called -BIST (Built in Self Test). I understand that, before a module enters its intended functionality, this BIST is made to run within the module. Once, this BIST is passed, ...
0
votes
2answers
120 views

What's the right way to read ID and CFI info from flash memory chips?

Our product has flash memory chip, but we have used more than one variant. The first is a SST/Microchip one and the second is a Spansion/Cypress. To determine which type is mounted, I read the flash ...
0
votes
1answer
35 views

Measurement of the retention period of a memory cell

Manufactures of Non Volatile memory devices give a quote for the Memory retention period of their device. To the best of my understanding, this period refers to the maximum period up to which the ...
0
votes
1answer
2k views

NOR Flash Memory Full chip vs Block vs Sector Erase

I am trying to use a NOR flash memory device: SST25VF016B (with STM32 discoveryboard F407VG). However, I am confused on some terms on their datasheet. You can find the datasheet here: https://www.elfa....