Signal Tap II display signals?

There should be 3 trigger options: instant, on trigger, or continuous on trigger.

Instant takes a snapshot now

trigger waits until the trigger occurs, then downloads the buffer

continuous on trigger will wait until the trigger condition occurs, download the buffer, then wait for the trigger to occur again. If you set no trigger conditions, it will just keep downloading the buffer (its not a continuous play function, you will miss the data in between the downloads).

You cant just download a specified number of clocks, you need to download the entire buffer.