Logic Won't decode SPI

1

Hello, I have an original Logic 8 (one of the $150.00 ones).
I use it all the time, great product.

I am trying to decode SPI signals from an old parallel port microcontroller programmer.

I have everything set up correctly, the software does not decode. I tried new versions of the Logic software, it is still the same result.

My theory is because the MOSI and MISO lines are always low when inactive. I would think this would not matter since the sampling is on the rising edge of SCK. The Logic program will successfully decode SPI signals when the MOSI and MISO signals are high when inactive (when trying to capture data with other spi devices).

Any help is greatly appreciated!

I have two screenshots I will upload.

Logic1.1.15
Logic1.1.151624Ă—504 134 KB
Logic1.2.14
Logic1.2.141918Ă—422 81.9 KB
SPI_Settings

1 Like
2

Looks like the enable channel might be low in the entire capture. When the enable channel is used, the SPI analyzer won’t start decoding until it sees a transition from inactive to active.
Try changing the enable channel to “none”.

Also, unrelated - where did you find such an old copy of the software? That older version was retired in 2014.

1 Like
3

That did it! Thank you.
The software now decodes correctly.
I bought the logic in 2009 and didn’t use it much until last 5 yrs or so.

I actually prefer the older software than the newer versions (at least for my skill level).

Thanks again for your support.

4

I have a logic pro 8 and the same thing happened to me. Thanks to this tip it works perfect.