Getting LED flash in Spartan3E 1600 Microblaze Development kit

Discussion in 'Embedded Systems and Microcontrollers' started by Peter Pan, Jan 6, 2008.

  1. Peter Pan

    Thread Starter Senior Member

    Mar 24, 2005
    122
    0
    Hello All,
    I am a newbie to FPGA and got recently a new Spartan3E1600 Microblaze
    development kit. I want very much to start doing something working and
    have decided that the best place to start is perhaps just to light on
    a LED on this board.
    So I have programmed a clock in VHDL which generates '1' and '0' every
    second (frequency = 1Hz) and download this to FPGA. However i do not
    know how to connect my clock to one of the 8 LEDs present on board (these are called LED0...LED7). Could you please, give me idea
    how to get my clock connected with a LED so that LED would flash with
    frequency of the clock?
     
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    You need to figure out where the actual IO pin is located, then you address it accordingly. That information should be in documentation.

    You should also have the IO setting configured for that pin, since drive levels and slew-rates are configurable.

    Steve
     
  3. Peter Pan

    Thread Starter Senior Member

    Mar 24, 2005
    122
    0
    Thank you. During implementation I assign pins and hence I know the name of the FPGA's pin which has to be connected with LED. But how to find an address of a LED and make the actual connection? Can it be programmed?
     
  4. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Page 18 of the users manual indicates the IO location of the LEDs.

    hgmjr
     
  5. Peter Pan

    Thread Starter Senior Member

    Mar 24, 2005
    122
    0
    Thank you, I have got it. I just wonder, what "A8" in the line below means?

    NET "LED<7>" LOC="A8"
     
  6. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Take a look at sheet 13 of 14 of the schematic that is included in the manual and you will see the 8 leds in the upper right corner of the schematic. Just follow the signal labels back from there and you will be able find what device is used to drive them.

    hgmjr
     
  7. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    After further study of the schematic, I found that "A8" is the pin designation on the FPGA to which LED7 is connected.

    hgmjr
     
  8. Peter Pan

    Thread Starter Senior Member

    Mar 24, 2005
    122
    0
    So LED7 is already physically connected to A8 pin of FPGA. In this case, all what I have to do in order to make LED7 flashing is to assign output of my signal to A8 pin during implementation. Is my understanding correct?
     
  9. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Yes. That should do it.

    hgmjr
     
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