# SPI clock and data

**URL:** <https://discuss.saleae.com/t/spi-clock-and-data/3083>\
**Category:** Uncategorized\
**Created:** [October 2, 2024, 3:29pm UTC](https://discuss.saleae.com/t/spi-clock-and-data/3083 "2024-10-02T15:29:46Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mike.c.williams](https://avatars.discourse-cdn.com/v4/letter/m/8edcca/32.png) [@mike.c.williams](https://discuss.saleae.com/u/mike.c.williams)\
**Post date:** [October 2, 2024, 3:29pm UTC](https://discuss.saleae.com/t/spi-clock-and-data/3083/1 "2024-10-02T15:29:46Z")

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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?

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**Author:** ![BitBob](https://avatars.discourse-cdn.com/v4/letter/b/ecb155/32.png) [@BitBob](https://discuss.saleae.com/u/BitBob)\
**Post date:** [October 2, 2024, 11:39pm UTC](https://discuss.saleae.com/t/spi-clock-and-data/3083/2 "2024-10-02T23:39:35Z")

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See this post for some ideas:

> [@Saleae logic pro 8 captures incorrect signals with Software version 2.3.37](https://discuss.saleae.com/t/saleae-logic-pro-8-captures-incorrect-signals-with-software-version-2-3-37/1203):
>
> 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](https://support.saleae.com/user-guide/using-logic/software-glitch-filter)
- Confirm [voltage level setting](https://support.saleae.com/user-guide/supported-voltages) 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)](https://support.saleae.com/user-guide/using-logic/navigating-the-software#id-2.-configuring-input-channels-and-setting-the-sampling-rate) 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!