How to make circuit that control number of clock pulses?
Well if you are doing this sort of thing (simulation), then in your example the most simple way is to use full adder. What you basically want to do is to build a 4bit full adder, then connect "A" inputs to the "number" you want to decrement from and "B" inputs in "0001" form (decrementing one). BUT, this way you´ll be adding 1, so you need to XOR ALL "B" inputs and carry in 1. This way, you´ll increment -1, so basically substract 1. Also, "A" input MUST be d-latch, and you want to wire output to "A" register, otherwise you´ll substract 1 and it will stop. This way, every clock cycle the output of adder will latch into "A" register, adder will substract (lol) and wait until next clock cycle.. I´ll provide schematics if u want, don´t have currently time :P