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Topic: SPI wierdness (Read 308 times) previous topic - next topic


Hi all,

I just converted a graphics display driver from SPI bit-bang to hardware SPI. Works fine.

Strange thing though... it works REGARDLESS of which SPI mode I use!

The datasheet for the graphics device shows transfers on the rising edge of SCK and SCK idle mode is logic 1 which means "SPI Mode 3" (and mode 3 works).

But, modes 0 thru 2 ALSO work?

What the heck is going on here? Any ideas?
Gentlemen may prefer Blondes, but Real Men prefer Redheads!


I suspect that as long as the data is stable when SCK goes from low to high it gets clocked in okay.

So, 0000000011111000000 works,
and 1111000011111111111 works
                 | as long as the data is done changing by here
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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