5 years, 4 months ago.

Multiple Instances of SPI1 Signals

Hello All,

I see two or more instances of SPI1 signals in the header pin-out diagrams for the ST Nucleos. For instance, on the L152RE diagram shows SPI1 MISO on PA_6, PB_4, and PA_11.

Does this mean that these three pins always carry the same signal when SPI1 is in use? In other words, can I attach an SPI peripheral's MISO line to any of these three pins and get the same results?

Many Thanks, Laz

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5 years, 4 months ago.

It means you can use either of those sets of pins with SPI1 (So just a regular SPI object), but you can't use them at the same time. Only those you actually set in your SPI definition will be active, the others you can use for other functions.

Hi Erik,

Thanks for your response.

When you say 'sets' of pins, do you mean that I must use the MOSI MISO and Clock that appear in the same block on the diagrams? For example must I always use PA_4, 5, and 6 as a group?

Thanks again for the help, Laz

posted by Laz R. 23 May 2014

Thats badly worded from me. I don't have a Nucleo board, but that shouldn't be the case, any combination of SPI1 pins should work. It is just that most often you will use a 'set', simply because it is just as easy to connect if you take pins which are together.

posted by Erik Olieman 23 May 2014