Hello Rich,
If its a 500 ms Delay, you can just find the exact time by analyzing the instructions you use and flow of the program ( ex How many times a particular instruction is executed ).
Reciprocal of the bus frequency is the time for one Cycle.
If an instruction uses 3 cycles, time taken for execution is (3 * time for one Cycle ).
I dont know much about the IDE method to calculate.
Raghu Sorab