Clock Speed Clock Cycle Time =========== ================ 1 Khz ==> 1/1000 = 1 ms (milli) 1 Mhz ==> 1/1000000 = 1 us (micro) 1 Ghz ==> 1/billion = 1 ns (nano) Example: Clock Speed ??? =========== ================= 100 Mhz ==> If we know that 1 Mhz clock has a cycle of 1/million = 1 us And we understand the inverse relationship between speed and cycle we then multiply one side by 100, we divide other side by 100 So 1 Mhz ==> 1us 100 Mhz ==> 1/100 us Since there are 1,000ns in a us 100 Mhz ==> 1000 ns / 100 = 10ns Example: 10 Ghz ==> 1 ns / 10 there are 1000 ps in a ns 1000 ps / 10 = 100 ps Problem: If a circuit contained 2 gates in series, each which took 10ns to traverse, what is the fastest clock that could regulate that circuit? Need to have a minimum tick of 20ns. 1 ns tick => 1 Ghz clock = 1000 Mhz clock As the tick get longer, the clock gets slower... 10ns tick => .1 Ghz clock = 100 Mhz clock There is an inverse realtionship between clock cycle and clock rate: If you multiply length of clock cycle by x, then divide clock rate by x 20ns tick => .05Ghz clock = 50 Mhz clock