Introduction
The Power Tracker View provides a graphical display of a device’s power usage synchronized to SATA protocol analyzer traffic. This capability is available on the Sierra analyzer platforms that can accept Teledyne LeCroy expansion cards (Sierra models: M6-2, M6-4, M122, & M124). The Power Tracker View is synchronized with other trace views that are open. One can therefore easily view the device’s power usage at the precise point where commands are issued or during other bus events of interest. It is necessary to install an optional “Sierra External Power Expansion card v2” (PN ACC-EXP-005-X) to use this feature. The External Power Expansion card is used to power the device-under-test (DUT).
Installation instructions for the card can be found in the M6-2 and M6-4 User’s Manuals and in the “Recording DevSlp” technical brief.
Activating Power Tracker
To utilize the Power Tracker graphical display it’s necessary to activate the feature in the recording project from the “Settings” page (See Figure 2). Selecting at least one of the voltage checkboxes will enable the Power Tracker data collection for the current project. The Power Management settings must be re-enabled for each project if power measurement is required.
To enable Power Tracker:
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Click the “Power Management Setting…”button to open the Power Management Setting window.
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Choose which voltage channels you wish to monitor (note: the PN 921097-00 and PN 921095-00 cables supplied with the ACC-EXP-005-X card only connect to the 12.0V and 5.0V channels).
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The Time Interval controls the sampling rate of the power measurement. Lowering the sampling interval will consume additional recording resources.
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Click OK.
Display Manipulation
A graph of the DUT’s power usage will now be included in the recording. One reason why Power Tracker is not activated automatically is that it causes the analyzer to consume the recording buffer faster. Setting a longer Time Interval will reduce the sampling frequency and allow longer recording.
When a SATA Protocol Suite trace was captured with Power Tracker activated, the lightning bolt icon on the toolbar will be enabled. If Power Tracker was not activated, the icon will be greyed out. To open the Power Tracker View, click on the lightning bolt icon or select it from the “Analysis” drop-down menu. The full screen button will expand the graphical display to provide a broader vertical scale. In general the Power Tracker is most useful when used in conjunction with another trace view such as Spreadsheet View or Packet View. By default, all open views are synchronized by time. Clicking in one view will cause the other view to jump to the same timestamp.
Navigation Modes
Pointer Mode – This is the default mode that comes up when one opens Power Tracker View. In this mode precise Power, Voltage, Current and Timestamp values are displayed at the position of the cursor.
Zoom by H Drag – This mode allows zooming out to get the highest level view of the DUT’s power usage throughout the entire recording (see Figure 3). Clicking and dragging to the left zooms out, clicking and dragging to the right zooms in.
Sync by Time – Activating this selection places a gold-colored pointer at the top of the Power Tracker View window that syncs precisely with the timestamps in other open trace views.
Zoom by Selection – Allows one to greatly enlarge (zoom in) on a specific area of the graph. Select the spot of interest, click on it and drag the pointer diagonally upward and to the left. (Figure 4.)
Figures 2, 3 and 4 show Power Tracker View open in conjunction with Packet View. This makes it easy to correlate specific bus events in the trace and the DUT’s power usage. The Insert Time Marker can be used to perform timing measurements between two points in the Power Tracker display. Click and drag the cursor between any two points to perform timing measurements (Figure 5).
Right-clicking at any point in the trace provides a menu to “Go To” the minimum or maximum voltage and current values in the Power Tracker graph.
