ram | 易学教程

模型机CPU设计——RAM和稳定器（13）

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RAM和稳定器 1 RAM可以根据quartus直接生成LPM_RAM_IO，实现读外接文件mif的读写 RAM接口和功能由quartus提供：但是RAM存在着不稳定的问题，会出现读取操作不是由下降沿控制而只受到控制信号控制的问题，所以这个时候我们用VHDL设计一个稳定器来稳定RAM的读取操作： Stabilizer稳定器设计：（1）部件功能：稳定器用来配合RAM使用，处理因为RAM输出的数据不稳定问题。（2）接口设计：输入： EN：使能信号，1有效 Clk：时钟信号 I[7…0]:数据输入，由RAM提供数据的输入输出： Bus[7…0]数据输出，连接到总线Bus RTL视图（3）功能实现：当EN有效为1时：如果clk=1，那么将输入加载到输出，否则输出保存值如果使能为0：输出高阻态，来隔绝总线，防止总线冲突 VHDL设计：（4）功能仿真验证：仿真结果：时钟为2.5ns: 使能EN=1，clk=1，输入X=00000001，将输入加载到输出，BU=00000001；时钟为3.5ns: 使能EN=1，clk=1，输入X=00000001，将输入加载到输出，BU=00000001；时钟为1.0ns: 使能EN=1，clk=0，输入X=00000001，将寄存器保存的值输出，BU=00000000；时钟为5.0ns: 使能EN=0，clk=0

How much memory a x86 excutable can use on a 64bit os?

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问题 I think that the question sounds clear, but for further explanation: Suppose we have Windows 7 x64 PC with 8GB of RAM installed on it; ( 64bit OS with 32bit process is my intention ) Question 1: how much memory can a 64bit process use in this environment? Question 2: how much memory can a 32bit process use in this environment? Question 3: If a 32bit process can only use 2GB of RAM in this environment,(even if it is LARGE ADDRESS SPACE AWARE: 3gb), however most games are 32bit;, so does this

How does PHP handle variables in RAM?

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问题 I am curious how PHP handles variables in memory? If I have 100 constants or variables set that hold values related to my application and not on a per user basis, like site name, version number, things like that, which all users have the same value. Will PHP put these 100 variables into ram 100 times if 100 users are hitting the page at the same time? Or does it somehow only store the value in RAM 1 time and all users feed off of that? 回答1: You could experiment with memory_get_usage() to

How can I show an image in webBrowser control directly from memory?

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问题 How can I show an image in webBrowser control directly from memory instead of hard disk? When I use RAM Disk software to create a virtual drive, it is possible to address an image source to load it like this: img src = "Z:/image.jpg" that Z is a RAM Disk drive. Is it possible to do that in .NET programmaticly? or use MemoryStream to do that? I would really appreciate some suggestions about this. 回答1: You can encode the image in base64. For example <img src="data:image/gif;base64

On Linux: We see following: Physical, Real, Swap, Virtual Memory - Which should we consider for sizing?

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问题 We use a Tool (Whats Up Gold) to monitor memory usage on a Linux Box. We see Memory usage (graphs) related to: Physical, Real, Swap, Virtual Memory and ALL Memory ( which is a average of all these ). 'The ALL' Memory graphs show low memory usage of about: 10%. But Physical memory shows as 95% used. Swap memory shows as 2% used. So, do i need more memory on this Linux Box? In other words should i go by: ALL Memory graph(which says memory situation is good) OR Physical Memory Graph (which says

Limiting node.js's memory usage

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问题 I am trying to limit a node.js application from using to much memory and I've found out about the --max-stack-size & --max_executable_size options that are available within V8 to pass when invoking the file, but how should I combine these and possible other arguments to limit max memory usage to 1GB? 回答1: https://github.com/joyent/node/wiki/FAQ What is the memory limit on a node process? Currently, by default v8 has a memory limit of 512mb on 32-bit systems, and 1gb on 64-bit systems. The

Get total available system memory with PHP on Windows

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问题 Using PHP, I'd like to get the total memory available to the system (not just the free or used memory). On Linux it's quite straight forward. You can do: $memory = fopen('/proc/meminfo'); and then parse the file. Is anyone aware of an equivalent method for Windows? I'm open to any suggestions. Edit: We have a solution (but StackOverflow won't let me answer my own question): exec( 'systeminfo', $output ); foreach ( $output as $value ) { if ( preg_match( '|Total Physical Memory\:([^$]+)|',

How is RAM able to acess any place in memory at O(1) speed

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问题 We are taught that the abstraction of the RAM memory is a long array of bytes. And that for the CPU it takes the same amount of time to access any part of it. What is the device that has the ability to access any byte out of the 4 gigabytes (on my computer) in the same time? As this does not seem as a trivial task for me. I have asked colleagues and my professors, but nobody can pinpoint to the how this task can be achieved with simple logic gates, and if it isn't just a tricky combination of

How to get the current CPU usage and available memory in batch file?

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问题 I am creating a simple script that outputs the current user logged in, CPU usage for the current system and the available memory? I have managed to get the current user/s logged on but is it possible to get the cpu usage and memory as well? This is my code so far. @echo off for /f "tokens=3 delims=\" %%i in ("%USERPROFILE%") do (set USER=%%i) 2>&1 echo "Logged On User: %USER%" echo. pause To get the cpu usage i have tried this command but it doesn't seem to be working. for /f "skip=1" %p in (

Memory usage doesn't decrease in node.js? What's going on?

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问题 I am tracking the memory using task manager and my app is a webrtc app using socket.io. So when I track the memory and open localhost, connect two browser windows, it obviously adds a little bit of memory. I think it starts at like 19.3 MB and then adds 0.5MB for each connection. HOWEVER! When I close out of the connection, so no more localhost windows are open, it never decreases in memory usage! So if it goes up to 20MB or something, then it will stay there and never ever decrease. Why is