The simplest way is to use direct parallel output from modified ADC_SAR component and route it to 12 output pins. Import ADC_SAR_ex from the project posed in #15 of this thread
The standard way would probably be to utilize SPI on both ends.
Thanks for your prompt response!
Considering the fact that I want to save I/O and go for SPI or UART (can?). What would be the big picture or the design? ADC=>DMA=>SPI or UART?