1ae1912ac048b708560c55a44c2139cae977e270

diff --cc simavr/sim/sim_irq.h
index f40809ccc19f02aae1a04dcf4a1deedd5bde7a43,756323b19e7463ba79e37108a5320756576bcdd7..b96fd4758cb1b5f4121afb54987f20caa49e219b
--- 1/simavr/sim/sim_irq.h
--- 2/simavr/sim/sim_irq.h
+++ b/simavr/sim/sim_irq.h
@@@ -55,7 -56,7 +56,8 @@@ enum 
        IRQ_FLAG_FILTERED       = (1 << 1),     //!< do not "notify" if "value" is the same as previous raise
        IRQ_FLAG_ALLOC          = (1 << 2), //!< this irq structure was malloced via avr_alloc_irq
        IRQ_FLAG_INIT           = (1 << 3), //!< this irq hasn't been used yet
-       IRQ_FLAG_USER           = (1 << 4), //!< Can be used by irq users
+       IRQ_FLAG_FLOATING       = (1 << 4), //!< this 'pin'/signal is floating
++      IRQ_FLAG_USER           = (1 << 5), //!< Can be used by irq users
  };
  
  /*