Question

You will drive the digital display on the board. The control inputs to these digits are driven in parallel, but there are logic lines to select which one(s) you are controlling at a particular time. To display different numbers on each digit, you will need to loop over them, selecting one at a time, and asserting the control signals for that digit, then changing them to move on to the next.

The LEDs in the displays are slow compared to the speed of the clock, and you will need to drive each one for about 2.5 µ sec for it to come fully on, before moving on to the next. How many cycles of the 100 MHz clock is 2.5 µ sec?

Answer 1

Number of cycles=clock frequency × delay time

N=100×10^(6) × 2.5 × 10^(-6)

=250