Spi protocol

[omeh-a]

This PR will add support for the new sDDF SPI protocol.

[Ivan-Velickovic]

It might be a good idea to probably just hold off on adding it here until we're happy with the design of the SPI.

[omeh-a]

It might be a good idea to probably just hold off on adding it here until we're happy with the design of the SPI.

Just leaving this draft PR open to follow changes as George works on the protocol, I can delete it if preferred though

[Ivan-Velickovic]

Just leaving this draft PR open to follow changes as George works on the protocol, I can delete it if preferred though

Fine to leave open, I just meant not worth changing this continuously as the protocol changes.

[omeh-a]

Just leaving this draft PR open to follow changes as George works on the protocol, I can delete it if preferred though

Fine to leave open, I just meant not worth changing this continuously as the protocol changes.

Ah yeah definitely not seeking to continuously update, just thought it would be nice to have a place for George to stick remarks!