C Application and Qsys

Hi all, do we have to make a complete Qsys System every time when we want to write an application to control the FPGA from software. I am confused because I am using cyclone V SoC and it has everything like peripherals, DRAMS, LEDS etc separate for HPS and FPGA and in Qsys we attach HPS and FPGA together. So for example if I define a register in my verilog code for FPGA then without making qsys system, can I just write a C program to send data in this register?
thanks in advance….

Which board??

In Cyclone V SoC boards no, the FPGA project has to include an HPS if you want to use it, otherwise the HPS is disabled. The only way to include an HPS is through Qsys. But you dont need to put your code inside Qsys as a Qsys component. You can use a GPIO and export it outside Qsys, or directly export the HPS-to-FPGA bridge. Then you include the Qsys system in a HDL file or Schematic and you add the rest of your logic in Quartus.

With newer devices (Arria, etc.) I ve heard that HPS and FPGA are independent, so maybe you can work with FPGA and HPS separatedly but i dont think you can do it anyway, because you need to define how to connect FPGA components and HPS, and this is done through Qsys.

Looks that you dont understand the boot process and connection between HPS and FPGA. Have you read the Cyclone V SoC Handbook volume 3 chapter 1?? HAve you done the tutorials for your board??

Hope it helps.