vhdl 101

Discussion in 'VHDL' started by martstev@gmail.com, Aug 13, 2006.

  1. Guest

    I am fairly new at VHDL...have two questions:

    1) any recommended books with loads of exampls - VHDL and digital
    logic.(I know there is so much FREE on the web, but I want to start
    with fundamentals)

    2) any suggestion about how can i code following timing signals in VHDL

    thanks in adavance

    this is what want to do...
    based on my inputs, I want to generate some timing signals..
    for examples: if my input (4bit wide) is "0001", I need to create a
    10uS pulse (T1) avery 1ms and want to created another pulse (18us wide)
    2uS after the leading edge of T1



    _______ _______
    | | | |
    | 10us | | 10us |
    T1 | | | |
    ________________| |________________________| |_________________
    |<-------------- 1ms -------------->

    __________ __________
    2us---->| |<---- | | |
    | | | |
    T2 | 18us | | 18us |
    __________________| |________________________| |_______


    thx,
    MARTIN
     
    , Aug 13, 2006
    #1
    1. Advertising

  2. Andrew FPGA Guest

    Do you want to generate T1/T2 in a simulator or in real FPGA hardware?
    If simulation you can do things like "wait for 10 us;". If the target
    is FPGA hardware then you must use vhdl constructs that are
    synthesizable ( wait for xx us is not). The FPGA hardware should have a
    clock signal. Use counters that count clock ticks to generate whatever
    delays you would like.

    E.g. say you have a 10MHz clock source. To generate a pulse 1 us long
    you need to count for 10 clock cycles.



    wrote:
    > I am fairly new at VHDL...have two questions:
    >
    > 1) any recommended books with loads of exampls - VHDL and digital
    > logic.(I know there is so much FREE on the web, but I want to start
    > with fundamentals)
    >
    > 2) any suggestion about how can i code following timing signals in VHDL
    >
    > thanks in adavance
    >
    > this is what want to do...
    > based on my inputs, I want to generate some timing signals..
    > for examples: if my input (4bit wide) is "0001", I need to create a
    > 10uS pulse (T1) avery 1ms and want to created another pulse (18us wide)
    > 2uS after the leading edge of T1
    >
    >
    >
    > _______ _______
    > | | | |
    > | 10us | | 10us |
    > T1 | | | |
    > ________________| |________________________| |_________________
    > |<-------------- 1ms -------------->
    >
    > __________ __________
    > 2us---->| |<---- | | |
    > | | | |
    > T2 | 18us | | 18us |
    > __________________| |________________________| |_______
    >
    >
    > thx,
    > MARTIN
     
    Andrew FPGA, Aug 13, 2006
    #2
    1. Advertising

  3. Guest

    Thank you Andrew for your reply!
    Yeah..I need this for the FPGA hardware. So I suppose I have to
    implement counters to generate T1 and T2. is that a true statement??

    Martin


    Andrew FPGA wrote:
    > Do you want to generate T1/T2 in a simulator or in real FPGA hardware?
    > If simulation you can do things like "wait for 10 us;". If the target
    > is FPGA hardware then you must use vhdl constructs that are
    > synthesizable ( wait for xx us is not). The FPGA hardware should have a
    > clock signal. Use counters that count clock ticks to generate whatever
    > delays you would like.
    >
    > E.g. say you have a 10MHz clock source. To generate a pulse 1 us long
    > you need to count for 10 clock cycles.
    >
    >
    >
    > wrote:
    > > I am fairly new at VHDL...have two questions:
    > >
    > > 1) any recommended books with loads of exampls - VHDL and digital
    > > logic.(I know there is so much FREE on the web, but I want to start
    > > with fundamentals)
    > >
    > > 2) any suggestion about how can i code following timing signals in VHDL
    > >
    > > thanks in adavance
    > >
    > > this is what want to do...
    > > based on my inputs, I want to generate some timing signals..
    > > for examples: if my input (4bit wide) is "0001", I need to create a
    > > 10uS pulse (T1) avery 1ms and want to created another pulse (18us wide)
    > > 2uS after the leading edge of T1
    > >
    > >
    > >
    > > _______ _______
    > > | | | |
    > > | 10us | | 10us |
    > > T1 | | | |
    > > ________________| |________________________| |_________________
    > > |<-------------- 1ms -------------->
    > >
    > > __________ __________
    > > 2us---->| |<---- | | |
    > > | | | |
    > > T2 | 18us | | 18us |
    > > __________________| |________________________| |_______
    > >
    > >
    > > thx,
    > > MARTIN
     
    , Aug 13, 2006
    #3
  4. On Sun, 13 Aug 2006 wrote:

    "[..]
    this is what want to do...
    based on my inputs, I want to generate some timing signals..
    for examples: if my input (4bit wide) is "0001", I need to create a
    10uS pulse (T1) avery 1ms [..]



    _______ _______
    | | | |
    | 10us | | 10us |
    T1 | | | |
    ________________| |________________________| |_________________
    |<-------------- 1ms -------------->

    [..]"

    The quoted text and the diagram do not correspond to each other: if
    something happens every 1ms then the period of 1ms should not be measured
    from the rising edge of one pulse to the falling edge of another pulse.
     
    Colin Paul Gloster, Aug 14, 2006
    #4
  5. willie

    Joined:
    Sep 13, 2006
    Messages:
    3
    A good book on VHDL and Verilog, it covers both, is
    HDL Programming Fundamentals VHDL and Verilog
    by Nazieh M. Botros
    ISBN 1-58450-855-8
     
    willie, Sep 13, 2006
    #5
    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. Kivak Wolf

    Drop down list 101

    Kivak Wolf, Oct 12, 2005, in forum: ASP .Net
    Replies:
    1
    Views:
    346
    Ken Cox [Microsoft MVP]
    Oct 12, 2005
  2. TheCoder
    Replies:
    1
    Views:
    395
    =?Utf-8?B?UGV0ZXIgQnJvbWJlcmcgW0MjIE1WUF0=?=
    Dec 2, 2005
  3. =?Utf-8?B?am9uZWZlcg==?=

    101 Question - Passing a value from one page to another

    =?Utf-8?B?am9uZWZlcg==?=, Dec 22, 2005, in forum: ASP .Net
    Replies:
    2
    Views:
    453
    uttara
    Dec 22, 2005
  4. Replies:
    0
    Views:
    643
  5. afd
    Replies:
    1
    Views:
    8,547
    Colin Paul Gloster
    Mar 23, 2007
Loading...

Share This Page