Define a 28-bit synchronous binary counter that uses the 100MHz clock, and a second 4-bit counter that uses one of the bits from the 28-bit counter as a clock. Select a bit from the 28-bit counter that toggles at about .5Hz to use as a clock for the 4-bit counter. Connect the 4-bit counter outputs to four LEDs. Configure your Blackboard, and verify the LEDS toggle at the correct rate.