Scientific SMO1000E, User Manual

Page: 94 / 185

Scientific
SMO1000E 94/185
I2C Triggering
This part introduces the nine kinds of trigger conditions (Start, Stop, Restart, No Ack,
EEPROM, 7 Addr&Data, 10 Addr&Data and Data Length) and the methods of setting
them.
To introduce the trigger conditions
Start Condition — the oscilloscope will be triggered when SDA signal transitions
from high to low while the SCL clock is high. If it is chosen as the condition of trigger
(including frame triggers), a restart will be treated as a “Start condition”.
Stop Condition — the oscilloscope will be triggered when SDA transitions from low to
high while the SCL is high.
Restart — the oscilloscope will be triggered when another “Start condition” occurs
before a “Stop condition” .
No Ack — the oscilloscope will be triggered when SDA data is high during any SCL’s
ACK bit.
EEPROM — the trigger searches for EEPROM control byte (the value is 1010xxx) on
the SDA bus. And there is a Read bit and a ACK bit behind EEPROM. Using Limit
Range softkey to set the qualifier and Data1 softkey to set the data’s value. If
EEPROM’s data is greater(less, equal) than Data1, the oscilloscope will be triggered
at the edge of ACK bit behind Data byte. It’s unnecessary that the Data byte musts
follow the EEPROM.