Search Results

Search found 5976 results on 240 pages for 'cpu cycles'.

Page 103/240 | < Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >

  • Adjusting the rate of movement of different objects on the same timer

    - by theUg
    I have a series of objects moving along the straight lines. I want to implement slight changes of velocity of each of the object. Constraint is existing model of animation. I am new to this, and not sure if it is the best way to accommodate varying speeds, but what do I know? It is a Java application that repaints the panel every time the timer expires. Timer is set via swing.Timer object that is set by timer delay constant. Every time the game is stepped objects’ coordinates advanced by an increment constant. Most of the objects are of the same class. Is there fairly easy way to refactor existing system to allow changing velocity for an individual object? Is there some obvious common solution I am not aware about? Idea I am having right now is to set timer delay fairly small, and only move objects every so many cycles of animation so that the apparent speed can be adjusted by varying how often they get moved. But that seems fairly involved, and I do not think it is the most elegant solution in terms of performance what with repainting the whole frame every 3-5 milliseconds. Can it be done by advancing the objects so many (varying) times during the certain interval (let’s say 35ms for something like 28fps), and use repaint() method to redraw just individual object? Do I need to mess with pausing animation for smoothness at higher redraw rates? Is it common practise to check for collision at larger step interval, but draw animation a lot more frequently?

    Read the article

  • Connecting / disconnecting DisplayPort causes crash

    - by iGadget
    I wanted to file a bug about this using ubuntu-bug xserver-xorg-video-intel, but the system prompted my to try posting here first. So here goes :-) While the situation in Ubuntu 11.10 was still somewhat workable (see UI freezes when disconnecting DisplayPort), in 12.04 (using Unity 3D) it has gotten worse. The weird part is that during the 12.04 beta's, the situation was actually improving! I was able to successfully connect and disconnect a DisplayPort monitor without the system breaking down on me. But now with 12.04 final (with all updates), it's just plain terrible. When I now connect an external monitor using the DisplayPort connector on my HP ProBook 6550b, it only works sometimes. Most times (but not always!) the screen just goes blank and the system seems to crash (not even CTRL+ALT+F1 works anymore). Only a hard shutdown by keeping the power button pressed for several seconds and then a restart gets me out of this. I suspect the chances of the system crashing become higher as the system's uptime increases, especially when there have been one or more suspend-resume cycles (although I have also experienced this bug once from a cold boot). Disconnecting is roughly the same as with 11.10 (see issue mentioned above), with the difference that if I resume from suspend, I no longer have to do a CTRL+ALT+F1, ALT+F7 cycle to get my screen back. So what more can I try? Or should I just go ahead and file the bug anyway?

    Read the article

  • Series On Embedded Development (Part 3) - Runtime Optionality

    - by Darryl Mocek
    What is runtime optionality? Runtime optionality means writing and packaging your code in such a way that all of the features are available at runtime, but aren't loaded and used if the feature isn't used. The code is separate, and you can even remove the code to save persistent storage if you know the feature will not be used. In native programming terms, it's splitting your application into separate shared libraries so you only have to load what you're using, which means it only impacts volatile memory when enabled at runtime. All the functionality is there, but if it's not used at runtime, it's not loaded. A good example of this in Java is JVMTI, Java's Virtual Machine Tool Interface. On smaller, embedded platforms, these libraries may not be there. If the libraries are not there, there's no effect on the runtime as long as you don't try to use the JVMTI features. There is a trade-off between size/performance and flexibility here. Putting code in separate libraries means loading that code will take longer and it will typically take up more persistent space. However, if the code is rarely used, you can save volatile memory by including it in a separate library. You can also use this method in Java by putting rarely-used code into one or more separate JAR's. Loading a JAR and parsing it takes CPU cycles and volatile memory. Putting all of your application's code into a single JAR means more processing for that JAR. Consider putting rarely-used code in a separate library/JAR.

    Read the article

  • What are possible causes of keyboard lag on my desktop machine?

    - by Jer
    I am running Windows 7 and began experiencing keyboard lag in most applications, and it seems to be getting worse. Certain websites are the worst - on some, I can type a sentence, take my hands off the keyboard, and watch the characters continue to appear on the screen for several seconds. Others are not as bad, but still noticeable and annoying. I just started noticing it in non-browser applications (e.g. Outlook) as well. I've disabled all extensions in Firefox, rebooted my machine, and that did nothing. There is nothing using much memory or cpu cycles, even when the lag is occurring. This is a machine at work with very strict controls over what can be installed, so the chances of any kind of malware are very slim. I don't believe anything as been installed since before the problem started. What could be causing this, and/or what can I do to debug?

    Read the article

  • Performance impact of Zones.

    - by nospam(at)example.com (Joerg Moellenkamp)
    I was really astonished when i saw this question. Because this question was a old acquaintance from years ago, that i didn't heard for a long time. However there was it again. The question: "What's the overhead of Zones?". Sun was and Oracle is not saying "zero". We saying saying minimal. However during all the performance analysis gigs on customer systems i made since the introduction of Zones i failed to measure any overhead caused by zones. What i saw however, was additional load intoduced by processes that wouldn't be there when you would use only one zone Like additional monitoring daemons, like additional daemons having a controlling or supervising job for the application that resulted in slighly longer runtimes of processes, because such additional daemons wanted some cycles on the CPU as well. So i ask when someone wants to tell me that he measured a slight slowdown, if he or she has really measured the impact of the virtualization layer or of a side effect described above. It seems to be a little bit hard to believe, that a virtualisation technology has no overhead, however keep in mind that there is no hypervisor and just one kernel running that looks and behaves like many operating system instances to apps and users. While this imposes some limits to the technology (because there is just one kernel running you can't have zones with different kernels versions running ... obvious even to the cursory observer), but that is key to it's lightweightness and thus to the low overhead. Continue reading "Performance impact of Zones."

    Read the article

  • A key principle of Scrum...

    - by AndyScott
    "A key principle of Scrum is its recognition that during a project the customers can change their minds about what they want and need (often called requirements churn), and that unpredicted challenges cannot be easily addressed in a traditional predictive or planned manner. As such, Scrum adopts an empirical approach—accepting that the problem cannot be fully understood or defined, focusing instead on maximizing the team’s ability to deliver quickly and respond to emerging requirements." I have been working in a SCRUM environment, with 4-6 week cycles, for about 6 months now and have been very pleased with the impact that it has had on my life (regular work hours, seeing my family, etc).  But was looking up the criteria for a 'Certified Scrum Master' and came across the SCRUM definition on Wikipedia, and started reading the actual definition.  My first thought was "hey, this development methodology actually allows you to deal with what happens in the real world (i.e. customers changing requirements); but is this "selling out" on solid requirements? I understand that this works in the environment that I am currently working in, where there are deep pockets paying the bills, and also making the descisions on what requirements to change / impliment; but is this a recepie for success in smaller or simply more budget concious environments?  Having the ability to be completely flexible when the client wants the product changed.   The more I think about it, the more I feel that SCRUM development may be better suited for an environment where a team is taking over a project from another team (bringing some outside development in-house or something of that ilk), as opposed to ground up development. What do you think?

    Read the article

  • Update a DNS to a for a dynamic IP

    - by zobgib
    I want to use my schools connection as a place to host a small webserver but one problem I have run into is anytime my server reboots I am given a new IP inside the schools range. All of the schools IP are public and therefor I can access my computer directly over WAN just via the IP given in ifconfig. I would like to be able to give my computer a dns which is easy enough when I change the Arecords to match the current IP of my computer. The problem is if my computer ever reboots (my school regularly cycles power at night and over holidays) I am assigned a new IP and have to realize it then update the Arecords This is inconvenient and I figure there must be a better way to keep the DNS records updated either via a script or my own BIND server. That way if there is a power cycle I can still access the server via a Domain Name. If you have any direction to point me in it would be much appreciated. I am running Ubuntu 10.04 if that helps :).

    Read the article

  • Software Center seems to freeze system when installing, syslog has "blocked for more than 120 seconds" errors

    - by nbm
    12.04 (precise) 64-bit Kernel Linux 3.2.0-39 3.6GB memory Intel Core 2 Duo CPU @ 2.40GHz x2 WUBI-installed Ubuntu running on a MacBook Pro 7.1 with OSX running Vista via Boot Camp (hey, I like lots of OS's m'kay?) When installing from Ubuntu software center my system very frequently freezes. This has happened 4 of the last 5 installs. Most recently I was installing the Google Earth .deb from Google's website: clicking the .deb file automatically opens Software Center (otherwise I would have used Synaptic, as I've grown to expect Software Center to freeze my system and I'm rather tired of it.) By "freeze" I mean nothing works: no dash, no launcher, no mouse movement, no alt-tab, can't open terminal (keyboard does not work). Software center does show the "installing" icon but after that it greys out and I can't click anything. REISUB has no effect but a cold power-down and restart is possible. Occasionally, after 5-10 minutes, I'll be able to move the mouse / use the keyboard and run a launcher command or two, although other open apps (Chrome and Software Center) will still be greyed-out/frozen. (I've never waited longer than that - if still unresponsive after 15 minutes I just power down and restart.) Most recently, which is why I am finally posting a question, I waited about 15 minutes and was finally able to open System Monitor while this was going on. Processes tells me that System Monitor is using about 20% of CPU, and nothing else is using much (zeros mostly). In fact I didn't even see Software Center listed? However at this point the system finally partially unfroze, the installation completed, and while I wasn't about to close Software Center I was able to do a system shutdown and fresh restart and I went and took a look at the syslog. In /var/log/syslog I see a lot of ":blocked for more than 120 seconds" messages. Similar to ubuntu hang out with this message :blocked for more than 120 seconds Which has not been answered, and I'm not running a virtual machine. My full syslog with stack traces looks very, very similar to this: Why do tasks on Amazon Xen instance block for over 120 seconds causing server to hang? Note that that question was solved, but that's because the problem was being caused by Amazon and Amazon fixed the bug. I'm not running anything Amazon-related. My syslog does look very similar, however. My question is also similar to this: Troubleshooting server hang But the referenced "duplicate" in that question is about how to kill processes/restart when the system freezes. I know how to kill processes and restart. I want to figure out what is causing the problem so I can try to fix it. I realize that I could just use Synaptic instead of Ubuntu Software Center, but I'd like to try to solve the problem if possible. I'm thinking I should perhaps submit a bug report, but I wanted to first see if anyone else was having any similar problems, and if so what you all did to fix it. I see a number of questions about Software Center freezing and others, including those I linked, about the "blocked for more than 120 seconds" log error, but I didn't see any question that links the two. I did save a copy of the syslog report if anyone wants to see it, but as mentioned it's quite similar to the one posted in the Amazon-related question...and I didn't want to take up even more space unnecessarily as, my apologies - this question has already become extremely verbose!

    Read the article

  • I can't see how a mature agile team requires any *management*?

    - by ashy_32bit
    After a recent heated debate over Scrum, I realized my problem is that I think of management as a quite unnecessary and redundant activity in a fully agile team. I believe a mature Agile team does not require management or any non-technical decision making process of whatsoever. To my (apparently erring) eyes it is more than obvious that the only one suitable and capable of managing a mature development team is their coach (and that being the most technically competent colleague with proper communication skills). I can't imagine how a Scrum master can contribute to such a team. I am having a great difficulty realizing and understanding the value of such things as Scrum and manager as someone who is not a veteran developer but is well skilled in planning the production cycles when a coach exists in the team. What does that even mean? How on earth someone with no edge-skills of development can manage a highly technical team? Perhaps management here means something else? I see management as a total waste of time and a by-product of immaturity. In my understanding a mature team is fully self-managing. Apparently I'm mistaken since many great people say the contrary but I can't convince myself.

    Read the article

  • Is it safe to compress my Windows 7 %USERPROFILE%\AppData folder?

    - by Kev
    Having just read Scott Hanselman's latest blog entry, Guide to Freeing up Disk Space under Windows 7, he suggests turning on NTFS compression which I already do for a number of less travelled folders that contain static files such as downloads or images. However I am wondering if it's wise to turn on NTFS compression for the whole of my %USERPROFILE%\AppData folder? My system drive is a 128 GB SSD residing in a Dell Precision T5400 3Ghz Quad Core Xeon workstation so I ought not to notice the extra cycles used to compress and decompress files on their way to and from the disk. However would there be any good reasons not to do this? In fact could I safely compress the whole of my %USERPROFILE% folder?

    Read the article

  • Two Hidden NetBeans Keyboard Shortcuts for Opening & Toggling between Views

    - by Geertjan
    The following are two really basic shortcuts for working with NetBeans editor windows that will be added to the Keyboard Shortcuts card for NetBeans IDE 7.2: Ctrl-Alt-PgUp/PgDown: Shortcuts for switching between editor types (e.g. Source, Design, History buttons). Switching between the editor types is a frequent operation sometimes, e.g., when using GUI builder, and while it can be done easily via mouse, or from View | Editors menu, it is very handy to know the shortcuts as well. Ctrl-PgUp/PgDown: Similarly, these are shortcuts for switching to next/previous opened document (tab). Note this is not like Ctrl-Tab that cycles in the last used order, but going through the tabs as they appear in the editor. Both shortcuts should fit into the "Opening and Toggling between Views" section. These are important to mention on the card because they are not visible anywhere else in the UI (as there are no menu items like "Go to next/previous editor type" or "Go to next/previous document"). Reported by Tomas Pavek from the NetBeans Team, here: http://netbeans.org/bugzilla/show_bug.cgi?id=213815

    Read the article

  • Any Windows based OpenID servers out there? [closed]

    - by Brian Knoblauch
    I've been looking to setup an OpenID server for a special project, but haven't found any workable OpenID server software packages. Originally was looking for a *nix solution, and found several, but they all had some kind of issue. So far I've tried JOIDS, community-id, and a couple others I unfortunately can't remember the names of. I've also come to the conclusion that even if I had managed to get one of those going that the management/upgrade cycles would have placed undue burden on the company (only a couple part time sysadmins with *nix knowledge, the day to day people are primarily Windows). So, I'm hoping that there's a Windows one out that will be functional that someone knows about and will be easy for a minimal support environment...

    Read the article

  • How to fundamentally approach creating a 'financial planner' application?

    - by Anonymous -
    I want to create a financial planning application (for personal use), for which the overall functionality will be this: User (me..) can create different 'scenarios'. Each scenario is configured with different incomings/outgoings. Scenarios can be 'explored' in a calendar format with projections taking into account tax, interest (on both debt and savings) and so on and so forth. My problem lies in how to fundamentally approach the project. I've considered: When creating incomings/outgoings for a script to apply them to each day in a 'days' table of a database, acting as a method of caching. This means that if I wanted to look at January 14th, 2074 there aren't thousands of cycles of calculations to run through and the result can just be pulled. Do each calculation dynamically, but again, I'm finding it hard to visuallize how I would handle different tax allowances (I'm based in the UK by the way), payrises and 'changes' to my incomings/outgoings. I've sat on this for a couple of days and am struggling to come up with an elegant approach to my problem. There may well be software out there that does what I'm looking to do (in fact I'm sure it is) but I would like to develop this myself for learning purposes, to be able to add it to my personal life 'toolset' and to allow me to expand on it in the future. Many thanks to all who have any input on my dilemna.

    Read the article

  • Pc not booting, no video output, hard drive noises

    - by bullettime
    My computer suddenly stopped booting up. I just came back from a week long trip, and it was working fine before I left. When I power up the computer now, it seems to power up just fine (leds on, fans working), but then there's no output on the screen at all, and there's a noise that seems to be coming from the HD, like it is trying to read something. After the noise starts, it does 6 cycles and then stops. I'm not sure but I don't think it did this noise when the pc was still working. I tried using the onboard video card instead but it made no difference. What could be wrong with my computer?

    Read the article

  • Best practice- handling images on website

    - by Steve
    I am porting an old eCommerce site to MVC 3 and would like to take advantage of design improvements. The site currently has product images stored in 3 sizes: thumbnail, medium (for display in a list) and expanded for a zoomed look. Right now we are having to upload 3 separate images that are sized exactly right, provide 3 different names that match what the site expects, etc., it is a pain. I'd like to upload just 1 file, the large one, then let the site reduce it to needed sizes, and I'd like the flexibility to change the thumbnail and list sizes depending on user preferences, form factor (e.g. mobile, iPad, desktop), etc. so might need many copies of the same image. My question is should the image be reduced then saved several times upon upload and if so what is a good storage/naming convention? The other idea is to store just the single image but resize it programmatically before serving it to the client. Has anybody done this and what are the tradeoffs besides a few more machine cycles? How do you pass a temporary image in memory to the client (there is no URL)?

    Read the article

  • Keyboard shortcut to cycle through programs (rather than just the alt-tab switch)?

    - by Steven Lu
    This question applies to both Windows and Mac OS X because I intend to use my mouse (Logitech G700) with both of them. The idea is I want one of my configurations to use two of my buttons to switch applications. However binding them to Alt/Cmd+Tab and Shift+Alt/Cmd+Tab is not good because the former functions as a toggle, and the latter cycles (in an unpredictable order). What I want is to move through my open applications in a circular buffer order. Do either of these OS's provide any keyboard shortcut that accomplishes this? I could live with just Alt/Cmd+Tab set to one button, but it limits me to being able to switch between only two programs.

    Read the article

  • Remotely initiate windows updates

    - by TetraFlash
    I have a network with countless workstations on it and the windows updates are done through WSUS in push cycles to allow us to use a generic image and configuration and avoid network congestion. I have a number of workstations in storage that are connected once a month for a few days to recieve updates, however not all of them fall within their push cycle. I want to avoid going to each machine and clicking "check updates" as that would require me to connect a monitor, mouse and keyboard. Is there a way (preferably through powershell but im open minded) to initiate a check and install of updates on a remote system? Lets say for 1 system at a time right now, I can add a file reader and a look later. NOTE: the configuration of the WSUS server is above my pay grade, im simply being asked to ensure these machines are updated. Thanks for any help or hints

    Read the article

  • Why using Fragments?

    - by ahmed_khan_89
    I have read the documentation and some other questions' threads about this topic and I don't really feel convinced; I don't see clearly the limits of use of this technique. Fragments are now seen as a Best Practice; every Activity should be basically a support for one or more Fragments and not call a layout directly. Fragments are created in order to: allow the Activity to use many fragments, to change between them, to reuse these units... == the Fragment is totally dependent to the Context of an activity , so if I need something generic that I can reuse and handle in many Activities, I can create my own custom layouts or Views ... I will not care about this additional Complexity Developing Layer that fragments would add. a better handling to different resolution == OK for tablets/phones in case of long process that we can show two (or more) fragments in the same Activity in Tablets, and one by one in phones. But why would I use fragments always ? handling callbacks to navigate between Fragments (i.e: if the user is Logged-in I show a fragment else I show another fragment). === Just try to see how many bugs facebook SDK Log-in have because of this, to understand that it is really (?) ... considering that an Android Application is based on Activities... Adding another life cycles in the Activity would be better to design an Application... I mean the modules, the scenarios, the data management and the connectivity would be better designed, in that way. === This is an answer of someone who's used to see the Android SDK and Android Framework with a Fragments vision. I don't think it's wrong, but I am not sure it will give good results... And it is really abstract... ==== Why would I complicate my life, coding more, in using them always? else, why is it a best practice if it's just a tool for some cases? what are these cases?

    Read the article

  • JBoss view active user sessions

    - by user49080
    We have a JBoss server with a single J2EE on it. I wish to find out who are the current active users using that application. Does JBoss give me any utilities that lets me view those existing sessions? (NOT the count, but who all are logged in) The question is kinda lame, but so is my JBoss knowledge :) I checked the JBoss community, but it only had a couple of relative unanswered questions there. The information i'm looking for would help me in maintenance cycles. I do not wish to reboot the system when users are still using it. We also need to keep a track of any illegal activities on our server. Hence the requirement. Would appreciate any pointers :) Regards, Abhi

    Read the article

  • Ubuntu 11.10 Random reboots how to find root cause?

    - by Indigo42
    All, This issue started with 11.04, I upgraded to 11.10 this week in hopes it would correct it, but after a few days it happened again.. A few times a day, randomly, my monitors will go black and the machine will come back in the post screen and boot up again. Sometimes it boots up properly, sometimes it boots to disk scan (I understand why...the machine just died with a bunch of stuff open) and sometimes it takes several cycles of this to come up. I connected to the system with my laptop and tailed dmesg, syslog, kern.log, and Xorg.0.log. I also ran a cat /proc/kmesg. Nothing is showing up in any of these log files when it happens..it's just like someone has pulled the plug. I just got through running 4 hours of the memory test with no errors. I have a AMD Phenom 9850 Quad-Core Processor and Nvida 9500GT graphics card. This system has been stable for like 4 years. I'm thinking it might be a hardware problem, but how do I find out? Thanks,

    Read the article

  • Keyboard that can't be removed (W8 CP)

    - by torazaburo
    Somehow I ended up with four keyboards installed (English (United States), Japanese (Japan), Kannada, and Hindi. They are installed in the sense that the tray drop down displays these four, and when I ALT-SHIFT through my keyboards it cycles through them. The mysterious thing is that in the Languages Control Panel, only the first two are shown, so I am stuck as to how to remove the last two. In the past, I may have installed and removed the Kannada and Hindi keyboards. What I did recently was to install the English (India) keyboard, as a way to get the ability to input the rupee symbol with ALT-CTRL-4. That English (India) keyboard did show up in the Languages Control Panel and allow itself to be removed. It almost seems like installing that keyboard somehow activate hidden registry settings left over from back when I had Kannada and Hindi installed. In any case, any ideas about how to remove these keyboards which don't appear in the Language Control Panel?

    Read the article

  • ??????????? - Java SE Embedded 8

    - by kshimizu-Oracle
    Java?OS??????1?????????????????????????????????3?????????????? HEAP: Java????????????????????????????????? NON-HEAP: NON-HEAP????JVM???????????????????Code Cache?Metaspace???2????????????? Code Cache: ????JIT??????????????????????????? Metaspace: HEAP??????????????????????????   JavaVM??????????: VM?????????????????? ??????????????? ????????????????????????????????????????????????????????????????????????? HEAP?Java Mission Control???????????????????? (????)? ????Java SE?????????????API????????????????????????????????????? Mission Control?????API?????????????????????????????????API??????????????? HEAP???????????? VM????????"-Xmx"???????????????? java.lang.Runtime.maxMemory(); ?????HEAP????????? ?????VM????????"-Xms"? ????????????? "-Xms"???????"-Xmx"?????????? java.lang.Runtime.totalMemory(); ???????????HEAP????????????? java.lang.Runtime.freeMemory(); ??NON-HEAP???????????? API??????????? Java Mission Control?????????? ????????????Java Mission Control??????????????????????? ????"NON_HEAP"?????????NON-HEAP?????? ???? HEAP????NON-HEAP?????????????? Java VM???????????????????????????????????????? ?????????????????????????????????? ????HEAP/NON-HEAP?????????????????????????? OS?????????????? Linux???????procfs?Java??????????????????? (VmHWM or VmRSS) ????? ????HEAP/NON-HEAP??????????????????????????? ?????????????????? ??????JVM?????????????????? ?????????????????JVM???????????????????? ???JVM?????? ????????????? Embedded??JVM?????????? ??Embedded???Oracle JVM??????CPU????????????????????????????????????????? ??????CPU??????????????????????????????????????? Minimal/Client/Server??JVM???????????????? ????JVM??????????????????? ??????Compact????????????????? ? 2 - 3?????? Concept Guide (http://docs.oracle.com/javase/8/embedded/embedded-concepts/basic-concepts.htm) ???????? ??JVM??????????? ????????????????????? -Xms: ??????????? ?????????? ?????????????????????????????????????????????????? -Xmx: ??????????? -XX:ReservedCodeCacheSize: Code Cache??????? ?) JIT??????????????Code Cache????????????0???????? -Xint: JIT??????????? ????????????? JIT?????????????????????? ????????????????? -Xss: ???????????????????? ????????????????????????? ????????????????????????????? -XX:CompileThreshold: JIT?????????????????????????????????? ?????????????????????? ????????? ?????????????????? Code Cache?????????? ?????????? ????????????????????? ????????????????????????? ??????????????????????? ?????????????????????

    Read the article

  • Is it possible to implement bitwise operators using integer arithmetic?

    - by Statement
    Hello World! I am facing a rather peculiar problem. I am working on a compiler for an architecture that doesn't support bitwise operations. However, it handles signed 16 bit integer arithmetics and I was wondering if it would be possible to implement bitwise operations using only: Addition (c = a + b) Subtraction (c = a - b) Division (c = a / b) Multiplication (c = a * b) Modulus (c = a % b) Minimum (c = min(a, b)) Maximum (c = max(a, b)) Comparisons (c = (a < b), c = (a == b), c = (a <= b), et.c.) Jumps (goto, for, et.c.) The bitwise operations I want to be able to support are: Or (c = a | b) And (c = a & b) Xor (c = a ^ b) Left Shift (c = a << b) Right Shift (c = a b) (All integers are signed so this is a problem) Signed Shift (c = a b) One's Complement (a = ~b) (Already found a solution, see below) Normally the problem is the other way around; how to achieve arithmetic optimizations using bitwise hacks. However not in this case. Writable memory is very scarce on this architecture, hence the need for bitwise operations. The bitwise functions themselves should not use a lot of temporary variables. However, constant read-only data & instruction memory is abundant. A side note here also is that jumps and branches are not expensive and all data is readily cached. Jumps cost half the cycles as arithmetic (including load/store) instructions do. On other words, all of the above supported functions cost twice the cycles of a single jump. Some thoughts that might help: I figured out that you can do one's complement (negate bits) with the following code: // Bitwise one's complement b = ~a; // Arithmetic one's complement b = -1 - a; I also remember the old shift hack when dividing with a power of two so the bitwise shift can be expressed as: // Bitwise left shift b = a << 4; // Arithmetic left shift b = a * 16; // 2^4 = 16 // Signed right shift b = a >>> 4; // Arithmetic right shift b = a / 16; For the rest of the bitwise operations I am slightly clueless. I wish the architects of this architecture would have supplied bit-operations. I would also like to know if there is a fast/easy way of computing the power of two (for shift operations) without using a memory data table. A naive solution would be to jump into a field of multiplications: b = 1; switch (a) { case 15: b = b * 2; case 14: b = b * 2; // ... exploting fallthrough (instruction memory is magnitudes larger) case 2: b = b * 2; case 1: b = b * 2; } Or a Set & Jump approach: switch (a) { case 15: b = 32768; break; case 14: b = 16384; break; // ... exploiting the fact that a jump is faster than one additional mul // at the cost of doubling the instruction memory footprint. case 2: b = 4; break; case 1: b = 2; break; }

    Read the article

  • AES BYTE SYSTOLIC ARCHITECTURE.

    - by anum
    we are implementing AES BYTE SYSTOLIC ARCHITECTURE. CODE:- module key_expansion(kld,clk,key,key_expand,en); input kld,clk,en; input [127:0] key; wire [31:0] w0,w1,w2,w3; output [127:0] key_expand; reg[127:0] key_expand; reg [31:0] w[3:0]; reg [3:0] ctr; //reg [31:0] w0,w1,w2,w3; wire [31:0] c0,c1,c2,c3; wire [31:0] tmp_w; wire [31:0] subword; wire [31:0] rcon; assign w0 = w[0]; assign w1 = w[1]; assign w2 = w[2]; assign w3 = w[3]; //always @(posedge clk) always @(posedge clk) begin w[0] <= #1 kld ? key[127:096] : w[0]^subword^rcon; end always @(posedge clk) begin w[1] <= #1 kld ? key[095:064] : w[0]^w[1]^subword^rcon; end always @(posedge clk) begin w[2] <= #1 kld ? key[063:032] : w[0]^w[2]^w[1]^subword^rcon; end always @(posedge clk) begin w[3] <= #1 kld ? key[031:000] : w[0]^w[3]^w[2]^w[1]^subword^rcon; end assign tmp_w = w[3]; aes_sbox u0( .a(tmp_w[23:16]), .d(subword[31:24])); aes_sbox u1( .a(tmp_w[15:08]), .d(subword[23:16])); aes_sbox u2( .a(tmp_w[07:00]), .d(subword[15:08])); aes_sbox u3( .a(tmp_w[31:24]), .d(subword[07:00])); aes_rcon r0( .clk(clk), .kld(kld), .out_rcon(rcon)); //assign key_expand={w0,w1,w2,w3}; //assign key_expand={w0,w1,w2,w3}; always@(posedge clk) begin if (!en) begin ctr<=0; end else if (|ctr) begin key_expand<=0; ctr<=(ctr+1)%16; end else if (!(|ctr)) begin key_expand<={w0,w1,w2,w3}; ctr<=(ctr+1)%16; end end endmodule problem:verilog code has been attached THE BASIC problem is that we want to generate a new key after 16 clock cycles.whereas initially it would generate a new key every posedge of clock.in order to stop the value from being assigned to w[0] w[1] w[2] w[3] we implemented an enable counter logic as under.it has enabled us to give output in key_expand after 16 cycles but the value of required keys has bin changed.because the key_expand takes up the latest value from w[0],w[1],w[2],w[3] where as we require the first value generated.. we should block the value to be assigned to w[0] to w[3] somehow ..but we are stuck.plz help.

    Read the article

  • Public class DiscoLight help

    - by luvthug
    Hi All, If some one can point me in the right direction for this code for my assigment I would really appreciate it. I have pasted the whole code that I need to complete but I need help with the following method public void changeColour(Circle aCircle) which is meant to allow to change the colour of the circle randomly, if 0 comes the light of the circle sgould change to red, 1 for green and 2 for purple. public class DiscoLight { /* instance variables */ private Circle light; // simulates a circular disco light in the Shapes window private Random randomNumberGenerator; /** * Default constructor for objects of class DiscoLight */ public DiscoLight() { super(); this.randomNumberGenerator = new Random(); } /** * Returns a randomly generated int between 0 (inclusive) * and number (exclusive). For example if number is 6, * the method will return one of 0, 1, 2, 3, 4, or 5. */ public int getRandomInt(int number) { return this.randomNumberGenerator.nextInt(number); } /** * student to write code and comment here for setLight(Circle) for Q4(i) */ public void setLight(Circle aCircle) { this.light = aCircle; } /** * student to write code and comment here for getLight() for Q4(i) */ public Circle getLight() { return this.light; } /** * Sets the argument to have a diameter of 50, an xPos * of 122, a yPos of 162 and the colour GREEN. * The method then sets the receiver's instance variable * light, to the argument aCircle. */ public void addLight(Circle aCircle) { //Student to write code here, Q4(ii) this.light = aCircle; this.light.setDiameter(50); this.light.setXPos(122); this.light.setYPos(162); this.light.setColour(OUColour.GREEN); } /** * Randomly sets the colour of the instance variable * light to red, green, or purple. */ public void changeColour(Circle aCircle) { //student to write code here, Q4(iii) if (getRandomInt() == 0) { this.light.setColour(OUColour.RED); } if (this.getRandomInt().equals(1)) { this.light.setColour(OUColour.GREEN); } else if (this.getRandomInt().equals(2)) { this.light.setColour(OUColour.PURPLE); } } /** * Grows the diameter of the circle referenced by the * receiver's instance variable light, to the argument size. * The diameter is incremented in steps of 2, * the xPos and yPos are decremented in steps of 1 until the * diameter reaches the value given by size. * Between each step there is a random colour change. The message * delay(anInt) is used to slow down the graphical interface, as required. */ public void grow(int size) { //student to write code here, Q4(iv) } /** * Shrinks the diameter of the circle referenced by the * receiver's instance variable light, to the argument size. * The diameter is decremented in steps of 2, * the xPos and yPos are incremented in steps of 1 until the * diameter reaches the value given by size. * Between each step there is a random colour change. The message * delay(anInt) is used to slow down the graphical interface, as required. */ public void shrink(int size) { //student to write code here, Q4(v) } /** * Expands the diameter of the light by the amount given by * sizeIncrease (changing colour as it grows). * * The method then contracts the light until it reaches its * original size (changing colour as it shrinks). */ public void lightCycle(int sizeIncrease) { //student to write code here, Q4(vi) } /** * Prompts the user for number of growing and shrinking * cycles. Then prompts the user for the number of units * by which to increase the diameter of light. * Method then performs the requested growing and * shrinking cycles. */ public void runLight() { //student to write code here, Q4(vii) } /** * Causes execution to pause by time number of milliseconds */ private void delay(int time) { try { Thread.sleep(time); } catch (Exception e) { System.out.println(e); } } }

    Read the article

< Previous Page | 99 100 101 102 103 104 105 106 107 108 109 110  | Next Page >