Cyclone® 10 GX Core Fabric and General Purpose I/Os Handbook

ID 683775
Date 7/08/2024
Public
Document Table of Contents

5.5.4.6. OCT Calibration Block in Cyclone® 10 GX Devices

You can use RS and RT OCT in the same I/O bank for different I/O standards if the I/O standards use the same VCCIO supply voltage. You cannot configure the RS OCT and the programmable current strength for the same I/O buffer.

The OCT calibration process uses the RZQ pin that is available in every calibration block in a given I/O bank for series- and parallel-calibrated termination:

  • Each OCT calibration block has an external 240 Ω reference resistor associated with it through the RZQ pin.
  • Connect the RZQ pin to GND through an external 100 Ω or 240 Ω resistor (depending on the RS or RT OCT value).
  • The RZQ pin shares the same VCCIO supply voltage with the I/O bank where the pin is located.
  • The RZQ pin is a dual-purpose I/O pin and functions as a general purpose I/O pin if you do not use the calibration circuit.

Cyclone® 10 GX devices support calibrated RS and calibrated RT OCT on all LVDS I/O pins except for dedicated configuration pins.