Altera DE1-SoC Diagram
Yes you can. This is simply an FPGA with a hardware ARM core instead of a soft ARM core (as the one you might want to instantiate in a regular FPGA). The hardware ARM core is connected internally to the FPGA logic through a high bandwidth interconnect Backbone. Here you can read a more detailed explanation: http://www.altera.com/devices/fpga/cyclone-v-fpgas/hard-processor-system/cyv-soc-hps.html