I'm trying to use the LCD screen on a SocKit board with a Cyclone V FPGA.

However, in the documentation I see that the chip is divided into an HPS and the FPGA and the LCD seems to be connected only to the HPS part.

Is it possible to use the LCD on this board directly from VHDL / FPGA without using the Arm processor? If yes, can anyone point me to some documentation on how I can interface into the LCD from VHDL? (I did search but couldn't find anything relevant yet, I'm just starting to learn VHDL.

  • \$\begingroup\$ It's impossible yo answer your question without knowing specifically what board you are using. Can you give us a part number? \$\endgroup\$ Commented Dec 15, 2013 at 6:42
  • 1
    \$\begingroup\$ I'm using a SocKit board from Terasic (part number P0160 the microchip code is Cyclone V SX SoC—5CSXFC6D6F31C8NES) \$\endgroup\$
    – MA81
    Commented Dec 15, 2013 at 7:53
  • \$\begingroup\$ Well, I have not used this particular chip before myself, but if the pins are dedicated to the HPS component then you may be out of luck. \$\endgroup\$ Commented Dec 15, 2013 at 21:54
  • \$\begingroup\$ Are you sure these are connected to the HPS specific I/Os? Last I checked there were connected to general purpose pins \$\endgroup\$
    – FarhadA
    Commented Dec 17, 2013 at 14:26

1 Answer 1


The SoCKit board uses a Cyclone V FPGA with an embedded Hard Processor System (HPS).

Altera's Introduction to Cyclone V Hard Processor System states:

The HPS and FPGA portions of the device each have their own pins. Pins are not freely shared between the HPS and the FPGA fabric

The SoCKit board connects with the LCD via an I2C interface which uses pins C23 & D22. Those pins are part of the HPS design and so they are not directly accessible to the FPGA fabric.

To determine if a given pin is accessible by the FPGA, or by the HPS you will need to check the pinout for your FPGA. In the case of the SoCKit design, the FPGA is in a FCSXFC6 package.


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