Sending data to SDRAM from FPGA on DE0-nano board

Hello,

I have a ADC interface logic that receive data regularly over 3.2MHz SPI link.

I want to send these data to SDRAM which is interfaced with Nios II system. Ultimately I would like to implement a 'snapshot mode' as mentioned in https://community.intel.com/t5/Programmable-Devices/Oscilloscope-High-speed-Application/m-p/148034

what is most efficient way to go about sending these ADC data to SDRAM?

I am thinking PIO for this.

Also what do I need to do on Nios II application to store data in SDRAM?

Thank you for your time.