I'd like to know about the lines on computer chips, like /CLK, /RW

Discussion in 'Technical Discussion' started by Andlabs, May 26, 2012.

  1. Andlabs

    Andlabs

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    Writing my own MD/Genesis sound driver :D
    I'd like to know more about the operation of the lines of a CPU's pinout, such as /CLK, /RW, /D0-D7, etc., including what physically happens and what each possible variation (such as tristate) are. Is there a place I could learn this online for free? Because I'm not exactly sure what this is called, I'm stuck as far as Googling goes... Or is there some book? Should I just leanr it in college? Thanks.
     
  2. erbuka

    erbuka

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    Well, it depends of what CPU you're talking about. If you talk about Intel CPUs, I think a full logic datasheet is not available. You should start with something easier like the Intel 8088. It is very old, but essentially it contains all the elements that can be found in the latest CPUs. You have the read/write cycles, interrupts and hold/holda protocol. Also, because Intel always want backward compatibility, you have the same ISA (instruction set architecture). Of course it has been extended a lot to support 32 and 64 bit systems, but, an assembly program made for 8088 could work even on the latest CPUs.

    Here is the datasheet of the 8088: http://html.alldatasheet.com/html-pdf/66062/INTEL/8088/123/1/8088.html
    As you can see, while this is a simple processer, there's alot of logic behind it. Take a look at the transistor count... You should get why it would be impossible to have a full descrption of a SandyBridge CPU :)

    The latest i3,i5,i7 are based mostly on the P6 architecture. When you understand the basics (8088), you can figure out what happens here, without knowing all the signals involved.
     
  3. LocalH

    LocalH

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    wouldn't you like to know
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  4. TmEE

    TmEE

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    CPU datasheets describe their pins and functions very clearly. There are timing diagrams and whatnot but the more complex the CPU the more complex those end up. Start with something simple as said before. Z80 is also a quite good place to start.

    If you want to go full hardware then learn boolean logic and look at the whole 74x series chips
     
  5. Andlabs

    Andlabs

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    Writing my own MD/Genesis sound driver :D
    Thanks. I was reading the Z80 manual before coming here first because I started getting confused about what they meant, actually. I was only naming /CLK and /RW as examples of what I meant... maybe I should be asking "how do pins and semiconductors work" :/ Some talk with GerbilSoft and Sik in IRC did clear up a few things somewhat, but are there any other resources? I'd still like to know more. Thanks for the other reading material though; it's interesting.
     
  6. Conan Kudo

    Conan Kudo

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