LED0 Always on (Logicstart with Papilio Pro)

Eric T

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I'm following the "Intro to Spartan" book and am running in to a issue.  No matter what I do LED0 is always on.  I am following the example program in Chapter 6.  I am using the Papilio Pro with the Logicstart Megawing.


I also have loaded the QuickStart bit file and see the same issue.  LED0 is always on. LED2, LED4, and LED6 flash as expected.


One other thing I have noticed is that when I first power the board all the LEDs turn on.  However, LED1-LED7 are dim.  LED0 is full power when first turned on.


I tried the following but LED0 remains lit:

LED_0 <= '0';


I'm hoping this is something simple.  Any ideas about why LED0 is always on?


Here is the UCF file I am using.  The vhd code is the same as in the "Intro to Spartan"

NET switch_0      LOC="P114" | IOSTANDARD=LVTTL; 
NET switch_1      LOC="P115" | IOSTANDARD=LVTTL;                              
NET LED_0         LOC="P123" | IOSTANDARD=LVTTL;                              
NET LED_1         LOC="P124" | IOSTANDARD=LVTTL;                              




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Hello Eric, 


It might help to download the latest version of the DesignLab IDE and try the LogicStart MegaWing example. This will at least let you know that the hardware is working as it should be. As for why LED0 is always on in your project, I don't have any ideas off the top of my head, maybe you can post the whole project as a zip file here?



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