Triggering the Oscilloscope

To use I2C triggering

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 Data softkey and the Data is softkey. When this event occurs, the scope 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.

Read

SDA

 

 

 

SCL

 

 

 

Start or

Control byte R/W Ack

Data

Ack

Restart Condition

 

Trigger point

Frame (Start: Addr7: Read: Ack: Data) or

Frame (Start: Addr7: Write: Ack: Data): the oscilloscope triggers on a read or write frame in 7-bit addressing mode on the 17th clock edge if all bits in the pattern match. For triggering purposes, a restart is treated as a start condition.

 

Read

Write

 

 

 

 

 

 

 

 

SDA

 

 

 

 

 

SCL

 

 

 

 

 

Start or

Address R/W Ack

Data

Ack

Stop

 

 

 

Trigger point

Restart

 

 

 

Condition

 

 

 

17th clock edge

Condition

 

 

 

 

 

 

 

 

 

3-26

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Image 88
Agilent Technologies 22A, 54621D, 24A, 42A, 54621A, 41A manual Frame Start Addr7 Read Ack Data or