You said:
So, I would like to set-up a simplest working interrupt logic and generate an interrupt, when '1' is written into the second bit in parallel port.
So, my condition for an interrupt:
IRQ <= '1' when iIRQEn = '1' and iRegDir(2) = '1' and ParPort(2) = '1' else '0';
In general, do not put a printf () in a ISR.
What do you have on bit 2 with the logic analyzer ? a square wave ?