Help with Agilent MSOX SPI triggering/decoding

[andrewwong2000]

Starting to really come to grips with the digital decoding capabilities of an MSOX, and I can't seem to figure this one out.

The problem is trying to use segmented memory to identify each 8 byte conversation between Master and Slave.

My test setup with an AVR programmer sending $AC $53 (Programming Enable) and $30 $00 (Read Signature Bytes) to an Atmega328p. There are 3 bytes to be read back (giving 0x1E950F).

Screen3.png shows the whole conversation. I am trying to get the segmentation capture to give me each 4 word conversation per segment.

After much experimentation, I found the most reliable trigger is Nth Edge (2nd rising clock edge) of CLK with an idle of 700us between clock words. The best I can do is capture bytes 1 (acknowledge programming mode), 2 (0x1E) and 4 (0x0F). It seems to always miss the 0x95.. and only give me back 3 segments if I use segmentation.

Using the SPI trigger with MOSI and all bits don't care gives me the first command AC53.. but doesn't trigger again for subsequent words sent by the Master (eg. segmented memory only recognises 1 segment).

My trigger holdoff is set to minimum 40ns (and I've tried any values in between).

Appreciate if anyone can help me figure out what I'm missing here. The signals are stable and repeatable,
and I'd like to get this working before I try to:

a. Get the decode lister to not group all the data into a single line
b. Decode something more significant like setting fuses, programming memory via SPI etc.