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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Monitor saying “No video input”, computer turns on however [migrated]

I really need help with this problem. Here's a detailed description of it: When I press the power button, the computer fires up with all the fans spinning and all the lights turning on. It'll ...
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1answer
53 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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1answer
62 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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4answers
100 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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2answers
150 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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4answers
118 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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4answers
510 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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1answer
142 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 ...
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3answers
50 views

Can one instantiate RAM with 2 read ports and 1 write port as IP in Quartus?

As part of MIPS design we have something called as register file. It only has 32 registers each 32 bit which only makes 1024 bits or 128 bytes. I am not sure how to tell Quartus to instantiate this as ...
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1answer
45 views

Memory Question

Picture of memory bank and questions: for b) The CPU should use address 101100 to store A in chip 2 with the location 22. My thought process is that the first bit decides which ram chips will be ...
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1answer
33 views

Problem with IAP

I'm using LPC1788 IAP to write to Flash and I'm a little confused on what's going on. I'm trying to write 8 bytes of data to Flash memory with 2 tehniques: 1) With one which is logical to me and it ...
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2answers
52 views

Memory design with 4 256K X 1 Bit IC's to a Z80

I have a couple of memory IC's lying around (16 of them) which I would like to use in my homebrew Z80 project. These IC's were produced by Samsung in 1988, the KM41256A 256K x 1 bit. I realise I can't ...
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2answers
105 views

ov7670 camera module [closed]

I really need some help to figure out whether the ov7670 camera module I bought is with or without FIFO. I bought it from a local market.Can someone please tell me how can I find out whether the ...
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3answers
65 views

Increasing cache line size when cache and RAM don't work asynchrounsly

I want to improve a processor design. It has a simple directly mapped cache, and I want to improve the hit rate. I've been working on increasing the cache line size from one data word to four, but ...
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3answers
83 views

How do MCUs and RAM wire up for programmatic access?

I am new to electronics and microcontroller programming and need either confirmation that my understanding on a few items is correct, or I am in desperate need of correction on them! I have a C-based ...
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3answers
257 views

64k x 8 RAM what exactly does it mean

I'm looking at this microcontroller because it has the protocols that I want and a really interesting price. My doubt is related with this field: RAM Size 64K x 8. What exactly does it mean? I know ...
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1answer
111 views

What type of memory allows for most parallel read/write operations per clock cycle in an FPGA?

If you imagine basic motion detection where you have two frames stored in memory: a previous 640x480 frame and the current 640x480 frame, what type of memory (SRAM, DRAM, SDRAM, DDR SDRAM, etc) would ...
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93 views

MDK-ARM uVision 5 stack RAM size for STM32

In my project I want store 150kB of bitmap in internal RAM of MCU. So, I've choosen STM32F407VET6 which has 192kB+4kB RAM. However, we must change some values in startup files to extend memory size ...
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1answer
62 views

searching in memory at verilog

I need to make a module which responsible to search overall memory to find a specific value and return the address location, but I have the following error after do Synthesize in Xilinx. ...
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2answers
116 views

Is there any 1 byte ic? [closed]

I need a system where 1 transistor = 1 bit. with a capcitor for each bit as ram, this would become space consuming, is there an ic that will act like 1 byte ram?
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2answers
124 views

How does CPU read data from the RAM?

In a general purpose computer(like normal pc), how does the CPU read the RAM, assuming that it first reads from the ...
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3answers
48 views

How can I replace this 5565 SRAM with a dual port SRAM?

I have an existing device (an arcade CPU board) that stores some data in a 5565 64-Kbit SRAM. I want to replace it with a dual-port RAM so I can read the data with a microcontroller. I don't need to ...
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2answers
443 views

Fesibility of using “computer RAM” with a microcontroller project

How feasible is it that I could connect the pins of some garden variety "computer RAM" to a microcontroller for use as external RAM? Is there specific hardware used on computer motherboards that help ...
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1answer
131 views

What happens when VRAM fails?

When VRAM fails within a video device, there appear to be certain common patterns of visual artifacts. This got me thinking - when VRAM (and RAM in general) fails, what is it that's actually happening ...
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0answers
193 views

How to set up the read part in Ram from Logisim?

I really need help for the read part in this project! Basically, we should build up a 4 nibbles Ram with 4 bits data register, 2 bits address register and 1 bit mode register. The problem is my ...
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1answer
305 views

problem with making 1 bit RAM memory using transistors?

I'm trying to make 1 bit RAM using four transistor ( 2 NOR Gates ). I built the 2 copies of the following circuit: I connected a LED to the output "F". Also, I connected Another LED to the output ...
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2answers
75 views

Verilog megawizard RAM not read

I used Quartus II Magawizard to ask for a two port RAM(one read and one write). The addresses are correct but the data out is always z. Can some one help me with this problem? I have stuck here for a ...
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2answers
77 views

What is DRAM atom size? Does it have any relation to the channel size?

I have seen that the channel size is in bits (64b/128b) which I understand is the amount of data one channel can transfer at an edge. But I see that the atom size is in Bytes. So does an atom of ...
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1answer
97 views

How a decoded picture is stored in a memory? [closed]

If we decode an image (any format) we will get matrix of pixels. For example consider a picture with resolution 10x10 and colour depth of 16777216. Therefore pixel is represented by 24 (888 RGB) bit ...
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1answer
104 views

Issue replacing 27C256 ROM with 62256 RAM

I'm trying to replace a 27c256 ROM with a 62256 RAM, to be able to easily change the memory content. I thought this would be pretty straight forward. Not quite, it seems. I made an simple ...
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4answers
645 views

What happens when microcontrollers run out of RAM?

It may just be a coincidence but I've noticed the microcontrollers I've used rebooted when they ran out of RAM (Atmega 328 if hardware specific). Is that what microcontrollers do when they run out of ...
2
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1answer
356 views

VHDL How to Design a Screen (Frame) Buffer

I am trying to use a screen buffer to store, change and output the bits of a video data to the DVI transmit interface. I am using Altera Cyclone III development kit. I will be using 1440x900@60Hz ...
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1answer
106 views

Where to put Bootloader Key in Ram, what address is the last ram address?

I am programming a CDC Bootloader. What I want to do is to run the program, from there write a bootloader key to the ram at a specific address and watchdog reset the MCU. The Bootloader reads exactly ...
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173 views

Random Access Memory Modelling in Verilog

Is there a better/alternative way of modelling RAM Memory in Verilog other than declaring it as an array of registers? Most of the sources I referred to have memories coded in the following manner. ...
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1answer
258 views

RAM memory modelling in Verilog

I am trying to model a 0.125GB RAM memory in Verilog using ModelSim of width 512 bit using memory chips of width 32 bit. So I have created a 32 * \$\2^{18}\$ memory array whose code is as follows: ...
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77 views

Creating Serial Pressence Detect data from discrete DDR RAM datasheet

I have a board that has soldered discrete DDR RAM chips. The datasheet for the DDR RAM chips is available to me. The DDR memory controller is programmed manually using pre-calculated values. I have ...
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3answers
397 views

Building larger ram from smaller ram

Using two 74F189 parts, implement 16x8 bit RAM circuit. Using two 74F189 parts and decoder, implement 32x4 bit RAM circuit. Using four 74F189 parts and decoder, implement 32x8 bit RAM circuit. Not ...
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2answers
80 views

IC for 4 Kbytes of RAM [closed]

Is there a Memory IC for 4Kbytes of RAM? I'm trying to make a schematic capture in Proteus and I need a Memory IC for 4Kbytes of RAM, I've searched throughout the library and I can't find one, tried ...
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2answers
131 views

Role of the MMU in a Page Fault Swap

When a virtual memory address outside the range of loaded into physical RAM is referenced and a page fault occurs, does the Memory Management Unit rely on DMA (Direct Memory Access) to swap the ...
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1answer
138 views

How do you store A or B in a RAM of a CPU datapath?

I have an assignment to make a CPU, but am confused with how f_left and f_right are going to be used. I think they are to store ...
2
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1answer
361 views

MSP430 RAM protection

I'm looking at the user guide for the MSP430x5xx family. It says there in section 9.1 that: ...
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3answers
267 views

How big is a single RAM cell?

I am studying on my own how the PC works and I can't understand one thing. A 32 or 64 bit processor differs for its ability to allocate 2 ^ 32 or 2 ^ 64 addresses for the cells of the RAM. What I do ...
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0answers
62 views

MAR /MBR / MUX Device

How can I modify this circuit to permit loading of the MBR from either the hex keyboard or from memory. As it is, the circuit can only load the MBR from user input.
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1answer
74 views

RAM and data copying/moving

I was wondering about the copying/moving of data in RAM and I couldn't help but thing about the possibility of having the RAM process basic memory operations such as copying/moving of memory, if ...
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2answers
188 views

Buffer management for SD card in SPI mode

I'm looking into implementing storage of large audio files onto an SD card. I'll be using SPI to access the card to avoid any patents by the SD card mafia. I'll be generating a lot of data, about ...
3
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2answers
355 views

FPGA RAM / SRAM in VHDL

Today I ran out of gates on my Xylinx Spartan 3 (Basys2 by Digilent) FPGA. This was not a surprise to me as I had implemented an 8 bit x 2048 array for use as an FIFO buffer. Code: ...
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3answers
130 views

If I pull the power on my computer and IMMEDIATELY restart it without booting OS, will RAM contents be preserved?

I have DDR3 RAM in my computer. My computer is frozen and I have important unsaved work open. I've already dealt with the problem of how to recover and read the contents of RAM. I just need to be able ...
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2answers
98 views

Can a computer and its RAM function properly if the temperature of the RAM has been significantly reduced?

This may be in the wrong section so if it is I apologize. I'm trying to significantly reduce the temperature of my computer's RAM so I can preserve it's contents during a PC reboot. I read about the ...
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51 views

Battery backed RAM for access by the OS

I apologize if this is the wrong place to ask this (just let me know where to go, if that's the case). I want to know if anyone has an idea how to set up battery backed RAM, like in an old S/NES ...
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1answer
53 views

Optimum aspect ratio for storing data in Block RAMs

I am working on Xilinx virtex 4 FPGA. I want to store some filter coefficients in Block RAMs. Specifically, I have many sets of filter, each set having 64 coefficient, each coefficient is of 18 bits. ...