Loopthrough a bidirectional signal in a fpga

Discussion in 'VHDL' started by Chabrie, Apr 17, 2008.

  1. Chabrie

    Chabrie Guest

    Hello Together,

    I have an Altera Sendero Video Board with a DVI Receiver and DVI
    Transmitter. In the first step, I want to loopthrough the DVI Signal
    through the FPGA. But now I have a problem. There is a bidirectional
    signal called DDC_Dat which I want to loopthrough. DDC is like IIC. But
    how can I connect the ports in the Toplevel? I want to do something
    like this: port1 : inout std_logic; port2 : inout std_logic; -->
    port1<=port2; port2<=port1; ??
    Could someone explain me the correct way to do this?

    Best regards
    Carsten
     
    Chabrie, Apr 17, 2008
    #1
    1. Advertising

  2. Chabrie

    KJ Guest

    On Apr 17, 4:02 am, Chabrie <>
    wrote:
    > Hello Together,
    >
    > I have an Altera Sendero Video Board with a DVI Receiver and DVI
    > Transmitter. In the first step, I want to loopthrough the DVI Signal
    > through the FPGA. But now I have a problem. There is a bidirectional
    > signal called DDC_Dat which I want to loopthrough. DDC is like IIC. But
    > how can I connect the ports  in the Toplevel? I want to do something
    > like this:   port1 : inout std_logic; port2 : inout std_logic; -->
    > port1<=port2; port2<=port1; ??
    > Could someone explain me the correct way to do this?
    >


    You'll have to know when DDC_Dat is supposed to go from port1->port2
    (or vice versa). That signal will tell you when port1 should be
    driven and when it should be tri-stated.

    port1 <= port2 when (Output_Enable = '1') else 'Z';
    port2 <= port1 when (Output_Enable = '0') else 'Z';

    If there is no way of knowing which way things are going at any
    particular instant then you can't drive port1 or port2.

    KJ
     
    KJ, Apr 17, 2008
    #2
    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. Manfred Balik
    Replies:
    12
    Views:
    6,605
    Marc Guardiani
    Sep 10, 2006
  2. Vikram
    Replies:
    0
    Views:
    823
    Vikram
    Jul 24, 2008
  3. TheRightInfo

    FPGA BOARD FOR NEWBIE TO FPGA

    TheRightInfo, Feb 2, 2011, in forum: VHDL
    Replies:
    1
    Views:
    1,346
    Tricky
    Feb 2, 2011
  4. Oliver Mattos

    Re: FPGA BOARD FOR NEWBIE TO FPGA

    Oliver Mattos, Feb 2, 2011, in forum: VHDL
    Replies:
    0
    Views:
    1,137
    Oliver Mattos
    Feb 2, 2011
  5. Amish Rughoonundon
    Replies:
    1
    Views:
    700
    Paul Uiterlinden
    Jun 11, 2012
Loading...

Share This Page