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External interrupt and SPI clock on same pin. Is it possible?

Paolo Andreuzza
Associate II
Posted on July 02, 2018 at 12:14

Hallo.

I'm developing an application, using a STM32L433.

My device is a SPI Slave that receive, every a fixed amount of time, a 4 bytes long frame on SPI3 port.

Since I need a time syncronization with the SPI master, my idea was to enable an external interrupt (EXTI) on the SPI clock pin, to manage a kind of time stamp, leaving the SPI fifo receiving the four bytes.

When I was in the 'timestamp' interrupt routine I would have disabled the EXTI interrupt.

At the end of processing the four bytes received by the SPI RX FIFO, I would have enable again the external interrupt in the SPI Clock pin.

The question is: is it possible that a pin used as SPI Clock, as slave (so the pin, in this case, is an input), triggers even an external interrupt?

Thank you in advance.

Paolo

1 ACCEPTED SOLUTION

Accepted Solutions
Posted on July 02, 2018 at 12:25

Yes, EXTI is independent of other functionality of the pin (as long as it's used as digital, i.e. not analog).

JW

View solution in original post

2 REPLIES 2
Posted on July 02, 2018 at 12:25

Yes, EXTI is independent of other functionality of the pin (as long as it's used as digital, i.e. not analog).

JW

Paolo Andreuzza
Associate II
Posted on July 02, 2018 at 17:29

It works, thank you!

Paolo