anchor.diff:  import TriState::*;
   import Vector::*;
   import XilinxCells::*;
  +import Probe::*;
   
   import ConnectalXilinxCells::*;
   import ConnectalConfig::*;
  
positive.code: 
     IOBUF sdaIOBuf <- mkIOBUF(axiIicBvi.sda.t, axiIicBvi.sda.o);
     IOBUF sclIOBuf <- mkIOBUF(axiIicBvi.scl.t, axiIicBvi.scl.o);
     rule iic_o;
        axiIicBvi.sda.i(sdaIOBuf.o);
        axiIicBvi.scl.i(sclIOBuf.o);
     endrule
  
negative.code:    rule rl_irq_levels_changed;
        let irq = axiIntcBvi.irq;
        let levels = intr();
  
        if (irq != irqLevel) begin
  	 $display("irq changed irq=%h intr sources %h", irq, levels);
  	 irqLevel <= irq;
  	 intrLevel <= levels;
  	 irqChangeFifo.enq(tuple2(irq, levels));
        end
     endrule
  