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2. I2C trigger
The I2C serial bus consists of SCL and SDA. The transmission rate is determined by SCL, and the
transmission data is determined by SDA. As shown in below figure, oscilloscope can trigger on the
start, restart, stop, ack lost, specific device address or data value, also device address and data
value at the same time.
In I2C bus trigger mode, the trigger setting information is displayed on bottom right of the
screen,for example,
, indicates that trigger type is I2C, CH1 trigger level is
0.00mV.
Menu
Settings
Description
Bus Type
I2C
Set vertical channel bus type as I2C trigger.
Source
SCL
SDA
Set SCL.
Set SDA.
When
Start
Trigger when SDA data transitions from high to low while
SCL is high.
Restart
When another start condition occurs before a stop
condition.
Stop
Trigger when SDA data transitions from low to high while
SCL is high.
Ack Lost
Trigger when SDA data is high during any
acknowledgement of SCL clock position.
Address
Trigger on the read or write bit when the preset address
is met.
Adr
Format
Addr
Bits
Set Address Bits to be
“7”, “8” or “10”.
Set address according to the preset address bits,
address range is 0-127, 0-255, 0-1023 respectively.
Set Data Direction to be
Write
or
Read
.
Note: The set is not available when Address bits is set to
“8”.
Address
Directio
n
Data
Search for the preset data value on SDA and trigger on
the dump edge of SCL of the last bit of the data area.
Data
Format
Byte
length
Set data byte length, available range 1-5 bytes. Click
or
to set byte length.
Select the data bit, ranges from 0 to (byte length*8 -1).
Set data to be H, L, or X (H or L)
Set all the data bits to be the specified value in Data
Current
Bit
Data
All Bits
Addr / Data
Set all the data bits to be the specified value in Data
Mode
Holdoff
Auto
Normal
Single
Acquire waveform even no trigger occurred
Acquire waveform when trigger occurred
When trigger occurs, acquire one waveform then stop
