Triggering
To trigger when expected data does not appear on the data bus from a remote device when requested
To trigger when expected data does not appear on the data bus from a remote device when requested
1Select the timing analyzer Trigger menu.
2Define a term called DATA to represent the expected data, the Edge1 term to represent the chip select line of the remote device, and the Timer1 term to identify the time limit for receiving expected data.
You can rename the Edge1 and Timer1 terms to match the problem domain, for example, to REM_SEL and ACK_TIME.
3Under Timing Sequence Levels, enter the following sequence specification:
∙Find “REM_SEL” 1 time
∙TRIGGER on “ACK_TIME > 16.00 μs” 1 time Else on “DATA” go to level 1
You will need to use the Timer Control field in the sequence setup for sequence level 2 to start the ACK_TIME timer upon entering that sequence level.
This sequence specification causes the analyzer to trigger when the data does not occur in 16 μs or less. If it does occur within 16 μs, the sequence restarts. Specifications of this type are useful in finding intermittent problems. You can set up and run the trace, then cycle the system through temperature and voltage variations, using automatic equipment if necessary. The failure will be captured and saved for later review.
