SPI clock and data

[mike.c.williams]

I’m using the Logic Pro 8 to look at SPI signals. On a scope, the clock is correct. I see 6 bytes clocked out as expected. On the Logic Pro 8, nothing looks right. The clock isn’t even close. I see 4-6 pulses that look random. It feels like a setup/tool issue but I can’t find anything that would seem to fix the problem. Any ideas?

[BitBob]

See this post for some ideas:

Saleae logic pro 8 captures incorrect signals with Software version 2.3.37

I am having trouble properly capturing signals with my Logic Pro 8. I recently installed The Logic 2 software version 2.3.37 and when trying to read the signals of an SPI line, I do not see the correct data appear. I have also tested with a Logic 8 on this same software and I seem to get the proper signals. Is there any insight someone may be able to provide to help me better understand why this does not work? Thank you!

Specifically:

• Check for glitches / use the software glitch filter
• Confirm voltage level setting vs. I/O
  (1.2V / 1.8V / 3.3+V on ‘Pro’ models)

… as well as:

• Check analog vs. digital view and confirm waveform/signal quality
• Check sample rate(s) are fast enough
  (Target: 10+X the SCLK frequency)
• Check ground connection(s)
  (Suggest SCLK channel on SPI as it’s highest frequency signal)

Hope that helps!