*I searched about the correct oscilloscope and probe to measure the a signal with a certain frequency. I read some documents and white papers about this topic. I have heard some "rule of thumbs" about the measurements : You should use scope and probe with a BandWidth of at least 5 times the Bandwidth of the signal to be measured. i.e : If I want to measure a signal of 200MHz differential DDR3 clock line, I need a Scope + Probe at least 1GHz BandWidth. OR, Rise Time / Fall-Time duration of 200MHz clock signal is much more important parameter than frequency of signal for correct Scope + probe selection?
*Another one is measurement options of Scope. If I try to measure above 200MHz, 50 ohm differential Clock lines from the input pin of DDR3; Which coupling should I select in the Oscilloscope? AC or DC? And how much termination should I select in the oscilloscope? 50 ohm or 1 Megaohm ? And why?