Four-sided Dice

 
Four-sided Dice

Problem statement:

I have three special four-sided dice.

They have one letter on each side.

When I roll them together I get three random letters which I try to rearrange into a word. In my eight goes so far I have made the words:
 
CAT, SON, POD, RIG, PEG, TAP, DIN, APE
 
What are the letters on each dice?

Done thinking? Click here to view the solution.

The letters on the three dice are:
 
CNPR AGDS EIOT