Modern digital storage oscilloscopes (DSOs) have been optimized for precise timing measurements on high-speed digital logic. The Tektronix TDS694C, for example, provides ±15 ps accuracy in signal edge to signal edge timing measurements. This high accuracy is achieved by an acquisition system that provides a maximum sample rate of 10 GS/s per channel. With its standard 3 GHz trigger bandwidth, the TDS694C can also trigger on very fast signal events. It cannot, however, trigger on a 64-bit wide bus address.
The TLA700 Logic Analyzer, on the other hand, has the ability to capture and display up to 680 logic signal inputs simultaneously. Using sophisticated trigger circuitry called a trigger state machine, the TLA700 Series can evaluate several "If-Then-Else" conditions at the same time. It can evaluate complex combinations of events and execute an extensive combination of actions; or it can capture specific events, such as memory read or write operations.
The TLA's MagniVu™ technology allows timing analysis on all input signals with a resolution of 500 ps. To do even more precise timing, the TLA7E2 and TLA7E1 DSO modules provide analog signal acquisition with 1 GHz analog bandwidth and up to 5 GS/s sample rate on each channel. The DSO module can be triggered from the TLA's digital acquisition modules and the digital modules can be triggered from the DSO module. Using the digital and DSO modules in a TLA 700, time correlation between digital and analog events can be accomplished. However, for many of today's high-speed logic signals the 1 GHz bandwidth of the DSO module limits the accuracy of the timing measurements. For the highest performance timing measurements, it is often necessary to use a stand-alone DSO, such as the TDS 694C, with higher bandwidth and sample rate performance.
By cross triggering the TDS694C with the TLA700, the user can take advantage of the best attributes of both to obtain precise timing measurements.