Recently I made a board with a BF518 that used the PPI with a 12-bit interface. I used the pins corresponding to D0-D11 and it worked fine except that I had to shift the data because it was zero-filled in the high bits.
Is it possible to connect to D4-D15 to avoid having to shift the data, or will the DMA still move the data in the low part of the word and zero fill the rest?
You already might have moved forward with your original design and may be its too late to go over this but just thinking what if you operate the PPI in 16-bit mode and just ground D0-D3 pins? This will work, right?
Thanks Kaushal, that will absolutely work, but I've decided to use D0-D11 and just take the hit on cycles. I'm maxed out on my I/O pins, so I can't afford to ground D0-D3.