Re: Xilinx VHDL coding styles,lookin for a tutorial

Discussion in 'VHDL' started by LittleAlex, Dec 2, 2008.

  1. LittleAlex

    LittleAlex Guest

    On Dec 2, 10:33 am, "blisca" <bliscachiocciolinatiscalipuntoit> wrote:
    > Hi
    > I am looking for information about good coding style when using Xilinx
    > devices(Spartan 3 mostly),i mean templates for correct and efficient
    > implementation of clock dividers,multiplexers,RAM and so on,so that the
    > result could be easy to analyze and synthesize to the tool
    >
    > Many thanks
    >
    > Diego


    When working with Spartan3 parts, I've found <www.xilinx.com> to be a
    good resource.

    <http://www.xilinx.com/support/documentation/application_notes/
    xapp215.pdf> - "Design Tips for HDL ...
    <http://www.xilinx.com/support/documentation/white_papers/wp275.pdf> -
    "Make your Design Up to 50% Smaller ...
    <http://www.xilinx.com/itp/xilinx10/books/docs/sim/sim.pdf> -
    "Synthesis and Simulation Design Guide"
    --- take a look at section 3 - "General Recommendations for Coding
    Practices"

    AL
     
    LittleAlex, Dec 2, 2008
    #1
    1. Advertising

  2. LittleAlex

    Tricky Guest

    Tricky, Dec 3, 2008
    #2
    1. Advertising

  3. LittleAlex

    Andy Guest

    The Synthesis and Simulation design guide also still uses (clock'event
    and clock = '1') instead of rising_edge(clock).

    They recommend not using array ports anywhere.

    They do not say anything about records, loops, variables or integers
    (let alone numeric_std types).

    For most users HDL coding starts out as "coding a shchematic netlist",
    where specific processes or entities represent low level primitives
    and constructs, interconnected together (the signals represent the
    wires from the schematic).

    But at some point, in order to improve design productivity above that
    of drawing schematics or coding netlists, we have to raise the level
    of abstraction. This includes not only effective use of data types,
    but also the way we describe complex circuits. Abstraction also allows
    us to focus on the intended behavior of the circuit, rather than its
    structure. To be fair, when performance is pushing the limits of the
    target device, a more structural-relative approach may be needed. But
    in most cases, for most of a design, this is not necessary, and an
    approach that more clearly relates the intended behavior is easier to
    debug. When coupled with advanced optimizations such as register
    replication and/or retiming, a behavioral approach is often just as
    relevant to the structure of the implementation as a structural coding
    approach would have been.

    Like Mike Treseler, I use processes with variables to define the
    behavior of a circuit. Signals are only used to connect between
    processes in the same architecture, and often there is only one
    (somewhat large) process per architecture, so there are no signals at
    all. Descriptions and processes written this way "behave the way the
    code reads", rather than having suspended updates of signal values,
    etc. I do not use subprograms (functions or procedures) as a template
    per se, but to collect and/or generalize reusable code.

    Andy
     
    Andy, Dec 3, 2008
    #3
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Mick

    Lookin for web timer sample

    Mick, Dec 10, 2004, in forum: ASP .Net
    Replies:
    2
    Views:
    435
    Steve C. Orr [MVP, MCSD]
    Dec 10, 2004
  2. Greg.franklin

    anyone lookin for a job?

    Greg.franklin, Jun 28, 2006, in forum: ASP .Net
    Replies:
    0
    Views:
    328
    Greg.franklin
    Jun 28, 2006
  3. Tricky
    Replies:
    1
    Views:
    695
    jeppe
    Dec 2, 2008
  4. Mike Treseler
    Replies:
    0
    Views:
    551
    Mike Treseler
    Dec 2, 2008
  5. Amal
    Replies:
    1
    Views:
    1,771
    vipinlal
    Mar 4, 2010
Loading...

Share This Page