I'm using the MK22FN1M0AVLH12 and the 12-bit DAC documentation seems to be a bit lacking. The DAC chapter doesn't seem to have anything to say about hardware trigger sources, and the chip configuration section for the DAC doesn't even mention triggers at all. The PDB section does show the DAC trigger. Is that the extent of the documentation, or is there more somewhere? The DAC block diagram looks like a joke, with the vague "other peripherals" block and "module signals".
I seem to have what I need for the moment. I was trying to do a simple coherent write to the DAC register in an interrupt, and it was getting a lot of glitches. The solution was to turn on the data buffer with the upper limit set to 0, trigger set to software mode, and then set the software trigger bit after writing to DACH and DACL. To me, this is probably the simplest and most obvious mode you'd want to use the DAC in, yet the documentation doesn't seem to address it.