I2C protocol does not trigger after changing the Address

[Wayne Contello]

I am using Waveforms (version 3.15.2) on mac OS X (10.15.7) and am having a problem using the I2C protocol trigger tool in the logic analyzer.

 

The basic problem is that I choose the I2C protocol trigger (with 8-bit address plus Rd).  When I set the Address to "h32",  the device will not trigger.  Then If choose a different value, like "h3E", the device will still not trigger.  So I change to a simple trigger of a calling edge on SCK and can see the various device addresses on the bus.

Here is what I do:

1) launch Waveforms

2)Open the device manager and choose configuration 4 (to get 16 x 16k or the logic)

3) Choose the Logic tool

4) Add an I2C channel with Clock = "DIO 1", Data = "DIO 0", Address = "8 bits RD zero", Format = HEX

5) Enable the protocol trigger.  Trigger = "Address & Data", Address = "h32", everything else = "ignore"

6) watch for triggers.... NONE.   my device is running with a SCK = 100kHz and I have about 5 devices on the I2C bus

7) switch to a simple trigger on the falling edge of clock.  I see plenty of bus traffic.

 

Any suggestions?

 

 

 

[Wayne Contello]

I think I figured it out...

The Address you enter in the I2C protocol trigger set up is ALWAYS 7-bit address (regardless) of the selection for the protocol set up selection (one of 7 bit, 8bit Rd, or 8bit).

 

Is this understanding consistent with the implementation?

[Wayne Contello]

For what it's worth... my opinion would be the form of the address you enter is consistent with the protocol selection.

 

[JColvin]

Hi @Wayne Contello,

I don't know the implementation within WaveForms itself, but I suspect your conclusion of the trigger only using a 7-bit address is correct as true 8-bit addresses (as far as I understand it) don't formally exist within the I2C specification. I think @attila is out of the office right now, but they will be able to see your feedback and clarify the implementation.

Thanks,
JColvin

[attila]

Hi @Wayne Contello

Thank you for the observation.
It is fixed for the next release. I've added format option also for the trigger dialog.