A few ways:

1. Read the datasheets. Some parts only support certain frequencies, so find the minimum of the master and slave frequencies. 2. Check at boot. Most devices boot slowly for the first few transactions then speed up. So if you saw valid data then aliasing, get a better kit. 3. Start high. I think the fastest serial memory devices cap out at 250 MHz DDR for volatile and 200 for non-volatile. So even a digital discovery (which I think is the best LA for high speed bursts) can deal with it