RAM is an abbreviation for Random Access Memory. A type of memory in which the information can be accessed from random location.

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Cache memory vs shadow RAM

I know that cache memory is much faster than typical RAMs. Apart from that, what exactly is the difference between Cache memory and shadow RAM? Both of them will have data that are to be accessed ...
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Do different address spaces exist for RAM and ROM in a typical microcontroller? [closed]

If a microcontroller has 16 bit address space from 0000H to FFFFH, will the RAM, I/O registers, memory mapped I/O and ROM(Flash/EEPROM) share the same address space linearly, or will there be a ...
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61 views

does this ensure i am reading from the ram?

I at the moment trying to reverse engineer something i made a long time ago but never understood why it is running so slowly. I have a Zybo board, with an Zynq 7010s chip ons which has dual cortex-...
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56 views

What is this component called

Suppose I have 512 leds in a 16 by 32 grid. I want to control what is displayed on the grid. To do this suppose I have a timer counter that is constantly counting between 0 and 31 in binary. This ...
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Shouldn't all the NAND gates in your computer activate at the same time? [closed]

When you plug in your computer, shouldn't all the NAND gates activate (because the output turns on when the both inputs are off) at the same time, causing chaos? For example: RAM is made of memory ...
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307 views

How do computers deal with RAM latency?

The clocks of CPU's have gotten faster than RAM. So computers have to wait a particular number of clock cycles between sending an address and receiving data. But how does a computer know how many ...
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502 views

What is the precise use of a memory controller and RAM latency?

I'm learning about synchronous DRAM and it often mentioned a memory controller. What exactly is the point of this? Couldn't the cpu just take the job of requesting and receiving data with its own ...
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1answer
49 views

What is precharge in terms of Static Ram?

In many six transistor static ram cell diagrams, it mentions a so called "precharge" that holds both bit lines at positive voltage. What is the use of this? wouldn't this constant voltage just screw ...
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78 views

How do I specify a microcontroller as RAM? [closed]

Recently I've been thinking of creating a basic game console using either SPI or Parallel interfaces (I would also like to know which would be the best and easiest for this situation). Using an ATMEGA-...
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59 views

Tolerances for DDR3 trace matching?

What would be an acceptable tolerance for length matching trace, for DDR3 SDRAM?
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63 views

Screen communication from a 8K RAM

I have recently completed the Nand2Tetris 1 on Coursera which lets you create a basic computer. For a while now I have been trying to physically implement the things I learned to create a fully ...
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2answers
158 views

Dual port RAM on Altera and Xilinx FPGA

I have always managed to synthesis a 256 x 32 bits dual-port RAM (not true dual port RAM) in Xilinx ISE with just 1 x 18K BRAM. The example code from here was used: ...
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59 views

Estimate RAM usage information of an embedded device [closed]

I'm monitoring the performance of an ARM-based embedded device which runs poky linux distro (from Yocto project) which contains OpenEmbedded build system. I need to get the MHz (CPU cycles) ...
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89 views

A computer system has RAM of 32K bytes and 64 peripherals. What is the number of distinct addresses required? [closed]

Is it correct to assume that the number of addresses for 32k of ram is 2^15 addresses? Then for the peripherals is it 2^6 addresses?
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76 views

Flash Magic for code dumping (LPC1778)

I was reading a book called "Insiders guide to the Phillips ARM7 based microcontrollers". There it says "The easiest way to program the Flash is by the built in bootloader which allows the code to be ...
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49 views

Some cool things i can do with RAM?? [closed]

What are some cool (technical) things i can do with RAM (500mb,ddr2)? I have it but cant't think of anything to do.
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235 views

Is program code copied to SRAM from flash on microcontroller?

On PC, program executable is read from hard disk, and loaded into RAM to execute it. On microcontroller, program is stored on flash. Is it loaded into SRAM when microcontroller starts up? If yes, ...
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41 views

How to calculate how much data a Core 2 duo E8 can write to the RAM per second?

I'd like to know how exactly I could calculate how much data the Core 2 duo E8 can write to the RAM per second, given that it is not overclocked and the RAM is 333MHz-DDR3?
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How do I get a value of a RAM by given address? [closed]

I think I know how RAM works, but I have an exercise where I have to read at the address 0x????. Furthermore, I am only interested what value get returned after the reading command. For example: ...
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Does a CPU completely freeze when using a DMA?

I have pretty straightforward question, but I couldn't find an answer to it anywhere. On a Von-Neumann system where code and data live in the same RAM, the CPU must fetch all its instructions from ...
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67 views

Memory Power Supply

Kindly any one give the clarification on this. While going through a DDR Memory data sheet, I have found two (more than that) power supply pins. What is the necessity of this DLL power supply ...
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192 views

What is the main difference between SRAM and DRAM in the automotive industry? [closed]

What are the main differences between SRAM(static RAM) and DRAM(dynamic RAM) in the automotive industry? What kind of memory does the different ECUs use? I'm interested in the BCM(body control ...
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204 views

Power of a microcontroller, but with more memory - what fulfils this need? [closed]

I'm a hobbyist with little experience. Usually I play with Arduino Pro Mini or ESP8266. I can make them do simple things I want, but for obvious reasons I can't give them too many features at once. E....
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116 views

4x1 bit RAM implementation

I have a circuit about 4x1 bit RAM. I should implement this at LAB. In this case I can make this easily but I dont know which element used for what purpose. Here is the figure. I googled it but ...
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133 views

Benefit of using RAM, or some form of internal memory on a FPGA

I am at moment trying to store an image onto an FPGA. I calculated the space required by it to be 19200 kb, and are therefor wondering whether i should store it some other way than a 2d array?.. Or ...
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278 views

Artix 7 Block RAM instantiation in Vivado 2015.2

Ok I'm trying to create a Block RAM instantiation in true dual port type. I have used the IP catalog and block memory generator in Vivado, which has given me a giant file that I now need to strip down ...
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Which is faster, Executing a program from ROM or RAM?

Most of us who are from electronics background knows that SRAM is faster than DRAM. But when it comes to comparing RAM with ROM, i am unsure. My question is related to micro-controller : "If a code ...
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CellularRAM CE# signal confusion

I'm trying to write a simple memory controller that does synchronous reads/writes for the Micron CellularRAM on the Nexys2 board (http://www.micron.com/parts/psram/cellularram/mt45w8mw16bgx-701-it). ...
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98 views

DRAM - is data pins order important when routing on PCB?

Quick question: I have SDRAM (SDR) and trying to connect it to uC. Can I route data bits from SDRAM to uC in any order? So they aren't connected respectively (d0->d0, d1->d2 ... d15->d15) but in any ...
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188 views

Isn't the term RAM technically incorrect? [closed]

I know that RAM is a word used to describe a type of memory that is volatile and more importantly doesn't have a speed difference when accessing different parts of the "memory grid". Isn't the last ...
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86 views

SRAM vs DRAM against single-event upsets

SRAM basically stores a bit in a flip-flop made of a few transistors, while DRAM stores a bit in a capacitor driven by a single transistor. Would this mean that SRAM is less likely to face single-...
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95 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, ...
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542 views

Is there a way to build a 2k*12 RAM using only 2 4k*4 Chips

Okay so I know when I need to build a parallel design I can put them near each other and make a 4k*8 to expand the databus. But on this one I only need to use half of them and the databus length is ...
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135 views

How many addresses are required for this system?

If a system has RAM containing 16K bytes with each of them needing their own distinct address and on top of that it has 16 peripherals and they each require 2^4 distinct addresses, then how many total ...
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162 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 ...
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130 views

Interfacing RAM to a DIY computer

I am a relatively newbie to electronics but hopefully this question is not very non sensical: I am following a guide to build a 8 bit computer. The guide requires a RAM which has a 4 address bit and ...
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My “flash VS RAM” speed test doesn't work. Why?

In trying to demonstrate that copying information from a string in flash memory to RAM takes longer than copying from the same information in an array in RAM to another, I ran the following code on ...
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Memory addressing with hex

If we have generic memory component that is \$2^{16}\times8 = 524288\$ Bits wide and CPU that that has address bus that is \$17\$ Bits wide. How could I locate this memory to begin from address \$ ...
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238 views

Building a SDRAM Controller (VHDL)

I am using the Spartan SP601 Evaluation Board, which includes 1 GB Elpida EDE1116ACBG-8E-E SDRAM. I would like to build a RAM controller, but have no experience in working with RAM before. I largely ...
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Is RAM always readable

I am currently interfacing with a temperature sensor (MLX90616) which stores data in certain ram addresses which can be accessed. I am interested in looking at the raw IR data as opposed to the ...
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Microcontroller memory limitations [duplicate]

I am really not able to understand why, when our personal computer memory is increasing in terms of gigabytes, the microcontroller memory is not increasing at that speed for both flash and RAM? What ...
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220 views

How to relate memory address to physical components in RAM?

I am trying to understand how are the micro-scale components arranged to relay address information to the Operating system software. What are the components that make up the ram which actually ...
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207 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 ...
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286 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 ...
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281 views

Understanding ROM/RAM in ARM MCUs

The 32-bit ARM SAM3X8E has 512KB ROM and 96KB of RAM onboard. This means that if I flash a binary to it that is, say, 400KB in size, and that consumes, say, 80KB RAM (max) at runtime, then that binary ...
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225 views

8-bit per cell memory?

I'm a software development student, who want to improve its hardware knowledge. I'm reading Structured Computer Organization by Tanenbaum. In the chapter 2, the author says the following: "[...] ...
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158 views

Eliminating micro current flow

I've built a RAM expansion cartridge for my VIC-20 computer. It uses the CY62256L 32KB SRAM chip. It has been working fine except there's a quirk. If I power off the computer, but leave the ...
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329 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 ...
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662 views

Why are the semiconductor chips (DRAM) volatile

Let me clarify, we all know Dynamic RAM is volatile in nature (it just won't hold data when it's turned off). I've been searching throughly about why instead of the 'what' about it, I just can't find ...
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2k views

How do I build RAM/CPU with logic circuits? [closed]

I want to build a little 4 bit computer, out of logic circuits. I want RAM and a CPU and all that good stuff. My main problem is, should I work on RAM or CPU, which one would "teach" me more so that I ...