Questions tagged [memory]
Consider instead more specific tags, e.g., dram, sram, flash
5
votes
2answers
294 views
Why have apparent memory bitflips in non-ECC memory not increased?
Back in the early 2000s I remember asking about why it was so important that servers use ECC memory. The prevailing wisdom at the time was that systems with lots of RAM would be, statistically, more ...
0
votes
0answers
63 views
Handling Large Variable Data with a Microcontroller
What is good practice for storing and manipulating variable data in a microcontroller circuit when the data may exceed microcontroller working memory?
In my application, I am designing an access ...
0
votes
1answer
37 views
Address decoding different bank sizes in 64K memory
I'm doing a small Motorola 6809-based computer project, and since I'm a bit rusty when it comes to boolean algebra I'm wondering if I'm doing my address decoding a bit too complicated for my simple ...
1
vote
2answers
71 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' ...
0
votes
0answers
15 views
Chaging EA/VPP by software on Intel MCS-51/8051
I'm designing a circuit that uses the combined Program/Data bus from Intel MSC-51 as advantage.
By the MCS-51 specification it has an internal 4K ROM and a EA/VPP pin that if set to high will access ...
0
votes
1answer
13 views
Is it possible to add a UID to M45PE10-VMN6?
Is it possible to add a UID to p/n M45PE10-VMN6 ? We need to add this security feature to these chips, but I am assuming it needed to be done at factory. Originally we could have purchased p/n ...
0
votes
1answer
25 views
Can more than one memory device transmit on the data bus at once?
I know that in general only one device can transmit over the bus at once, but if they are all memory devices, can they act as one? I have four 256x8 chips, which I think means that I have 256 cells ...
2
votes
1answer
70 views
Interfacing 16-bit SRAM/MRAM with Arduino Mega
I a looking to interface a MR2A16A 4Mb 16-bit MRAM with an Arduino Mega. I am new to interfacing with memory chips and would like some advice from someone more experienced than myself. I am not ...
0
votes
1answer
34 views
Reading memory array
im new to memory cells.
I have taken the below image from a video, i wanted to ask in the video he explains that the MUX can select 8 bits, but how is this even possible?
The output of a MUX is always ...
0
votes
1answer
44 views
Reading a MD25Q128SIG SPI flash memory with raspberry pi
I'm trying to read a MD25Q128SIG SPI flash memory with my raspberry pi, you can find its datasheet here: http://www.firstjit.com/Uploadfiles/20160121152131319.pdf
Here are raspberry pi pinouts:
Here ...
6
votes
8answers
3k views
What prevents the construction of a CPU with all necessary memory represented in registers? [duplicate]
Modern CPUs employ a hierarchy of memory technologies. Registers, built into the chip have the lowest access times, but are expensive and volatile. Cache is a middle-man between RAM and registers to ...
-1
votes
1answer
87 views
How to find the memory capacity? [closed]
A memory component spans the address range 0x00400000 to 0x007FFFFF, what is its capacity?
I only know the calculate the two ...
1
vote
0answers
39 views
S25FL512S flash driver, read or write not working correctly
I am trying to write a driver for an S70FL01GS chip, which is two stacked S25FL512S chips. I am successfully reading status register, SFDP register, RDID, etc. I am also able to toggle (and verify) ...
1
vote
1answer
85 views
Core rope rom not working
I am trying to make my own core rope rom, according to the link. I have 15mm ferrite cores, which I wound about 30 times with 1mm magnet wire. I thread the primary ( also 1mm wire) through one of ...
2
votes
4answers
116 views
How can we determine memory usage of a microcontroller
How can we determine how much memory is being used, or will be used by firmware in a microcontroller? What tools can support this?
Generally we don't use dynamic memory in embedded systems, but how ...
-3
votes
1answer
86 views
How to write STM32F4 OTP Area
I am reading the reference manual page 75 that shows the flash memory organization of STM32F4 MCUs. There is an OTP area of 528 Bytes in it as shown in the image:
Is it possible to write on this OTP ...
0
votes
0answers
22 views
Synopsys Technology File (STF)
I am using a memory IP block from STM. The manuals of the memory IP has talked a lot about Synopsys Technology File (STF), though, with no info on how and where to use it.
Among all files related to ...
0
votes
1answer
98 views
How to increase memory on the FPGA board?
Situation
I'm running a driver code driver.cc on the FPGA board (PYNQ-Z1) but it gives an error in the middle of the code where the code calls to ...
0
votes
0answers
19 views
Can FOTA be performed by changing the execution point of the code i.e, changing the program counter in lpc1759
For FOTA can we divide the memory into two blocks, eg : block A and block B.
And whenever there is a new version of firmware detected, we shall change the execution point of the code.
Is this ...
0
votes
1answer
57 views
Is a multiplexer needed to read from memory
we need to enable a register to write into that register, which is done using a decoder.
even if we enable 1 register using decoder, given that RD(bar) is 0, all registers can still produce an output. ...
0
votes
0answers
47 views
EPCQL controller
I am trying to access in read and write my EPCQL-1024 from simple soft running in NIOSII. I have the Altera Serial Flash Controller I configured in QUAD mode connected from its avl_csr and avl_mem to ...
0
votes
0answers
53 views
How to use Altium Multi-Board to define SODIMM board and socket connections?
I am attempting to use Altium 18.1.9's new "Multi-Board" feature to connect a 200-pin SODIMM board ---> to a SODIMM socket connector ---> on my mainboard PCB. This Altium article is just about the ...
0
votes
2answers
56 views
Maximum cells in a row in a SRAM memory array
I was considering designing an SRAM memory array. For my design to be useful in a certain system, I need to have several cells in a row (e.g. 1024, 2048).
In textbooks I have seen examples of arrays ...
1
vote
2answers
249 views
What does the number of “ single-word instructions ” mean on a MCU's memory specifications?
I have copied the following sentence from a PIC MCU datasheet:
"PIC18(L)F26K22, PIC18(L)F46K22: 64 Kbytes of Flash Memory, up to 37,768 single-word instructions."
the question is what does " 37,768 ...
1
vote
2answers
154 views
Designing a RAM, using 4x2 chips, with a 8 address capacity
This is a typical exam question, and I've seen some very helpful posts about, but I still have a lot of doubts.
Given an integrated circuit of certain dimensions, for this example a 4x2, I have to ...
1
vote
0answers
34 views
Finding the memory polynomial model coefficients
I want to build a memory polynomial model given that I know the corresponding output signals for known input signals. What is the easiest way to find the coefficients of it? And how do we take the ...
0
votes
2answers
71 views
What design differences make ram faster than ssd for read/write [closed]
I understand that RAM is connected directly to the CPU via a high bandwidth bus, and SSD is a peripheral, but my assumption is that there are also electrical design differences (e.g. memory cell ...
1
vote
2answers
71 views
Image memory on micro controller [closed]
I am trying to specify a microcontroller for a very simple task. All it does is show an image at boot up (which will most likely be black and white).
The display itself is 240*240 and 12bit color ...
0
votes
1answer
81 views
How to write more than one page at once in Winbond W25Q32JV
I am using Eclipse IDE for firmware development. I am using Quectel MC60 module with Winbond W25Q32JV (4 MB memory). The thing is that I am able to read/write single page.
I am facing issue with ...
1
vote
0answers
47 views
How is CAM implemented?
I have a book statement:
A content addressable memory is a circuit that combines comparison and storage in a single device.
I want to know how this is implemented in real world? Sounds like an ...
0
votes
1answer
46 views
Commercial SRAM with separate power supply for the core and peripheral?
Are there commercial SRAMs available with a separate power supply for the core transistors (6T) and a separate supply for the remaining circuitry such as the sense amps, write drivers, etc?
I believe ...
1
vote
3answers
137 views
Embedded Firmware Question - Memory dump
Ok so the back story is this. I landed an online code interview with a company that shall remain nameless.
I know I am not ready for a job there but I was basically given the chance by an insider. ...
0
votes
1answer
251 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....
1
vote
2answers
160 views
Finding the address of structure knowing the address of one of it's members in C
This sounds like a little too far fetched, but is there any possibility to find the address of a structure, if the address of one of it's members is known? The struct itself contains different data ...
1
vote
3answers
83 views
Is memory possible without a flip flop circuit?
All the memory circuits I've seen use some form of flip-flop/feedback mechanism to store a value. Is this the only circuit design that can store a value? Is there anyway to create memory without a ...
1
vote
1answer
308 views
Data Strobe in DDR memory
In DDR3 memory there is a signal called DQS that I have several question about.
What is DQS abbreviated for? specially Q
What is the purpose of data strobe in DRAM and why not use simple clock.
Is ...
0
votes
1answer
106 views
How do memory seats keep track of their position?
I was wondering how do memory seats keep track of their position. Since this kind of equipment existed in 1990's cars, it must be simple yet ingenious. I have been thinking about this for quite a time ...
-1
votes
1answer
90 views
Can a computer increase its memory in machine cycle? [closed]
For my college assignment, one of the question asks to explain how a computer increases its memory in machine cycle. I have searched and so far I have found that a computer can't increase it's own ...
0
votes
1answer
52 views
What is address allocation of memory register? [closed]
What is ment by address allocation of memory register in microprocessor and memory topic or in computer architecture?
Memory chips are have no processing elements(passive elements). How memory chips ...
0
votes
2answers
166 views
Does pin A15 on a Z80 tell if the CPU is addressing ROM or RAM?
I am designing a simple, hobbyist single board computer similar to an Arduino using a Z80 CPU. The trouble I am running into is how the CPU addresses memory. I know that the Z80 uses pins A0-A15 to ...
0
votes
1answer
34 views
Using narrower DDR RAM than controller
I have some ARM processor that have 72-bit width (8 for ECC) RAM controller.
Can I buy eg. two 32bit chips and combine them? If yes then how?
Can I buy just one 32bit and pull down rest of data pins ...
-2
votes
2answers
94 views
Memory choices for lack of arduino speed [closed]
I'm designing a system which reads values from a microphone and feeds it to the Arduino to calculate a few sound parameters. The measuring happens during a couple of milliseconds. The problem is that ...
1
vote
1answer
63 views
Memory Addressing How To? [closed]
I have read some about computer memory and the article said DRAM is mainly made from a transistor to direct the electricity and a capacitor to store them. I don't understand how it fills certain ...
1
vote
0answers
55 views
Improving a SRAM-based memory cell by reducing number of transistors
I'm working on Emulated version of a memory cell. It is a volatile single-bit memory.
It uses 4 NAND gates to store one bit. I want to connect several of those memory cells together to create one ...
0
votes
2answers
1k views
STM32H7 with 512MB SDRAM
I'm considering to design an audio processor based on the STM32H7. I want to experiment with MCU-based DSP instead of using a dedicated DSP. I chose this high-end ARM MCU to have ample headroom for ...
0
votes
2answers
105 views
Why is there a need for an eNVM and an eSRAM in the same SoC FPGA
SmartFusion2 SoC FPGA is distinguished by containing an embedded Non-Volatile-Memory (eNVM) that is used to store the code needed for the booting process of the FPGA after power up. So in the presence ...
16
votes
2answers
2k views
Parallel RAM without large number of pins?
Back in the 1970s, Texas Instruments had a now-discontinued range of products that they called GRAM (and read only equivalent GROM) which was basically a standard memory chip with address and data all ...
0
votes
1answer
108 views
Asynchronous SRAM routing crosstalk concerns
I'm routing a large BGA SRAM that is connected to a BGA FPGA, and there's about 40 signals altogether connecting the two. I'm using Henry Ott's recommended 8-layer stackup:
1 ________________Mounting ...
0
votes
2answers
86 views
Are memory-mapped registers actually implemented as real registers?
I am currently trying to better understand microcontroller-architectures and I am particularly studying the ARM cortex-m3 right now. What I have always wondered is, if memory mapped registers are ...
0
votes
1answer
71 views
How memory is stored in memories like SD Card, USB flash drive, etc. that the data stays even if removed to the device?
This latches ( Gated Latch, SR Latch, and Flip Flops) can only store memory IF there is electric current flowing, but everything will go OFF if no current.
I wonder how memory is stored in memories ...
