80
User Manual
IIC Triggering
After the oscilloscope has been set up to capture IIC signals, you can trigger on a
stop/start condition, a restart, a missing acknowledge, an EEPROM data read, a
read/write frame with a specific device address and data value, or on a data length.
1. Press the button
Setup
on the front panel to enter trigger function menu.
2. Press the
Type
softkey; then, turn the
Universal Knob
to select the serial slot (
Serial
1
or
Serial 2
) on which the IIC signals are being decoded above.
Figure 35 IIC TRIGGER Menu
3. Press the
Condition
softkey; then, turn the Universal Knob to select the trigger
condition:
Start Condition
— The oscilloscope triggers when SDA data transitions from high
to low while the SCL clock is high. For triggering purposes (including frame
triggers), a restart is treated as a start condition.
Stop Condition
— The oscilloscope triggers when data (SDA) transitions from
low to high while the clock (SCL) is high.
Restart
— The oscilloscope triggers when another start condition occurs before a
stop condition.
Missing Acknowledge
— The oscilloscope triggers when SDA data is high
during any Ack SCL clock bit.
EEPROM Data Read
— The trigger looks for EEPROM control byte value
1010xxx on the SDA line, followed by a Read bit and an Ack bit. It then looks for
the data value and qualifier set by the
Limit Range
softkey and the
Data1
softkey.
When this event occurs, the oscilloscope will trigger on the clock edge for the Ack
bit after the data byte. This data byte does not need to occur directly after the
control byte.
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