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Registered: ‎10-31-2007

Interrupt Controllers and LCD Display on a Spartan-3E 500

Hello Everyone,
    I'm a student at Cal Poly Pomona and I've been working for weeks on trying to integrate these 2 base features into a single simple program for my lab class.  ideally, by being able to give an appropriate, working model, I should theoretically be able to accomplish whatever else the professor may ask for, given enough time and thought. 
    The problem I'm running into is the fact that these two elementary aspects of the board seem to be directly in conflict with each other.  When I operate the board in my LCD knownGood program (a software controlled clock that is displayed on the LCD screen) I can get it to work properly and can values or manipulate the display however I will.  When I operate my interrupt controller knownGood program (binary counter which lights up appropriate LED's and increments every interrupt), my LED's light up as I would expect and increment according to how they're programmed to.  Now... when I try to implement these two features together, mainly, using the LCD to display a clock which increments everytime an interrupt occurs (every second), my LCD displays nothing at all, even though it uses the same exact knownGood code.  I kept the LED's also implemented into the design and, sure enough, the interrupts are still occuring and displaying correctly.
     If anyone has any ideas in regards to what I might be doing incorrect, I would greatly appreciate the insight.  I've wrapped my head around this problem multiple times, and each time, the logic all points to "it should work, why isn't it?"

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Xilinx Employee
Xilinx Employee
Registered: ‎08-07-2007

Re: Interrupt Controllers and LCD Display on a Spartan-3E 500

Hi Jason,
I'd suggest you debug with GDB and check if the code to write LCD get executed.
If it's executed, then you might also add a ChipScope core to observe the bus transaction to see if the transaction is as expected.
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