I have an XSA-50 board and am programming it to count the amount of high input signals from the header pins. The signal that I want to count is coming in at least 4ns as TTL signals--this is my clock signal in the verilog code, but not physically hooked to the clock pin on the board. Will this board be able to detect the signals, even though this signals have short time span ? Please note, I am very new to this timing stuff and would like some guidance. Also, please keep in mind that I looked at the signal on an oscilloscopes and it comes in very fast! I am currently using the Xlinx 9.1 package to do all of the simulations for this device; I looked at the wave forms using a nanoseconds range on the simulator and it functions fine.