Teledyne LeCroy Sierra M6-4 SAS_SATA Protocol Analyzer User Manual - Manual (Page 105)

Sierra M6‐4 SAS/SATA Protocol Analyzer User Manual 103
SAS/SATA Software Menus and Toolbars Teledyne LeCroy
Pre-Trigger
You can set the amount of data to capture before and after the trigger, as a 
percentage of pre‐trigger, between 1% and 99%. Position the pre‐trigger slider to a
percentage. This feature allows the evaluation of bus activity leading up to and after the
triggering event. Figure 2.69 illustrates the operation of pre‐trigger in data memory.
Pre‐trigger data is capture of the specified percentage of data prior to the triggering
event. It cannot be guaranteed and may be 0. This can occur when the triggering event
occurs before storing the required amount of pre‐trigger event data. In such a case, the
data display shows fewer than the specified data points prior to the triggering event.
Figure 2.69: Pre-Trigger Example, 20% Pre-Trigger