Teledyne LeCroy Serial Data Debug Solutions - Manual (Page 91)

Operator's Manual
919586 RevA 91

WS (or FRS, for TDM Protocol Variant) - The Word Select field is enabled when using the LJ and RJ
AudioBus protocol variant. Click the field and select either a Falling or Rising value.
The same field is in display mode when using the Audio I2S AudioBus protocol variant.
Lastly, the field is changed to FRS (Frame Select) when using the TDM AudioBus protocol variant. Click the
field and select either a Rising or Falling value.

Audio Freq - This display field shows you the channel data value as a frequency for Left and Right (or 1-8
for TDM AudioBus protocol variant) for your reference.

Start Bit - Only selectable when using the TDM AudioBus protocol variant. Enter a value using the pop-up
numeric keypad.

#Data Bits - Provide a field value using the pop-up numeric keypad.
L EVEL R IGHT -H AND D IALOG
The DATA, CLK, and WS signal sources can each have their levels adjusted from this dialog.
Level Type and Vertical Level - The message decoding algorithm setup is performed here. The level is normally
set up in %, and defaults to 50%. Adjust the level by touching inside the number area to highlight the box title,
and then use the oscilloscope front panel Adjust knob to make your change. Alternatively, touch inside the
number area twice and select a value using the pop-up numeric keypad.
PLEASE NOTE THE FOLLOWING:

When Muting a decoded signal or using a Mute Trigger, set your source level types to Absolute. Adjust
the voltage level so it moves to a position above the muted trace on the display grid.

The set Level appears as a dotted horizontal line across the oscilloscope grid.

If initial decoding indicates there are a number of error frames, make sure that the level is set to a
reasonable value.
Creating an AudioBus Trigger Condition
The AudioBus trigger can be configured for I2S, LJ, or RJ variants. Powerful conditional triggering can be applied
to either left or right channel data, while unique triggers like
mute , clip , and glitch help isolate rare problems
not easily detected by viewing decoded data alone. AudioBus turns the oscilloscope into a protocol analyzer
with a customizable table display of protocol information which you can even export into Microsoft Excel
format.