the problem with SPI is that you have to generate the CS signal as well (and maybe also the LDAC pulse if you want the output to update at a specific, fixed rate)
I did it in the past (not with this MX but i don't recall anything that couldn't make it work), not sure if it's there is a better approach, but...
I used two CCP modules, SPI and DMA.
- CCP module 1 generate a small pulse for LDAC
- CCP module 2 generate a wider pulse, long enough that the SPI frame is contained in it
- DMA to start an SPI transfer with CCP module 2 as a trigger
I had also to be "clever", assigning different values to the CCP module timers so that they started out of phase between each other (so pulse 1 active would be while pulse 2 inactive) or if both CCP are run by the same timer, use output compare mode instead of PWM to achieve the same thing
Since you are new to PIC32, have you tried doing it the easy way first? (manual update, so you can confirm that connections are good)