Sending output pin to input pin in the other .bdf file

Well, there is this standard procedure.

Let me explain with an example. Suppose I have 2 circuits: a counter ( in any form: counter.v/counter.vhd/counter.bdf) & a comparator (again in any form comparator.v/comparator.vhd/comparator.bdf).

Now I wish to supply the output of the counter as a ramp input to the comparator, in order to generate a PWM.

procedure:

1) Open the counter file in Quartus II.

2) Go to file -> create/update -> create symbol files for current file

( this command will compile your counter circuit & save a symbol file called counter.bsf in your project directory)

3) Do the same thing with the comparator file.

4) Now, create a new BDF file, call it pwm_generation.bdf

5) Double-click anywhere inside to bring-up the symbol window. There click the '+' sign before 'project' where you will find your counter & comparator.

6) Just bring them together on this new block diagram file, and do the required input-to-output wiring ! That's it.

( You may also edit & customize the individual counter.bsf & comparator.bsf symbols to suit your connection routing )