I think I was wrong.
fpga clock is 40Mhz --> 1 / 40000000 = 2.5e-8
AI sampling is 51.2 kHz --> 1/51200 = 1.9531e-5
and fpga 1 tick is 2.5e-8 [s]
1.9531e-5 / 1 [tick] = 781.24
and i want loop timer set that's number (781.24 tick)
How do i handle decimal points? (0.24 tick)
1tick * 0.24tick = 6ns
it's means 1 loop time error is 6ns????
1[sec] later 0.3072[ms] error...
what is the best?? i set loop counter 781 or 782??