SPI 10-bit mode ?

[espruino-discuss2]

Posted at 2017-12-21 by @yerpj

Just saw that SPI can send 4-bit nibbles (http://www.espruino.com/Reference#l_SPI_send4bit) or 8-bit bytes (http://www.espruino.com/Reference#l_SPI_send8bit).
What about 10-bit mode?

[gfwilliams]

Posted at 2017-12-21 by @gfwilliams

I'm afraid not - send4/8bit are actually special-purpose functions that still send 8 bits at a time. They basically replace each bit with a 4 or 8 bit bit pattern.

All the SPI functionality is 8 bit, so if you needed something different you'd have to do it in software yourself.

[espruino-discuss2]

Posted at 2017-12-21 by @yerpj

I see. Thanks for the feedback.

It is quite unusual to have to deal with SPI peripherals that doesn't exchange on 8-bit, however the Character display introduced here http://forum.espruino.com/conversations/313620/#comment13972928 is actually talking with 10-bit data... I'll try to bitbang it.

[gfwilliams]

Posted at 2017-12-22 by @gfwilliams

Ahh - some of them offer that instead of having a Data/Command bit. It looks like software SPI could be tweaked to handle it reasonably easily - it's just not easy to do across the board as most things are expecting bytes.