Agilex™ 7 General-Purpose I/O User Guide: F-Series and I-Series

ID 683780
Date 7/08/2024
Public
Document Table of Contents

2.4.1.2. OCT Calibration Block

You can calibrate the OCT using the two OCT calibration blocks available in each GPIO bank.

Each OCT calibration block can calibrate the I/O buffers in GPIO banks located in the same row only. For example, you can use the OCT calibration block in bank 2A to calibrate the I/O buffers in banks 2A, 2B, 2C, and 2D but not the I/O buffers in banks 3A, 3B, 3C, and 3D.

Each OCT calibration block can calibrate two RS OCT and two RT OCT settings for all I/O standards except the POD12 I/O standard. If you use the POD12 I/O standard, each calibration block can calibrate one RS OCT and one RT OCT for the POD12 I/O buffer, and one RS OCT and one RT OCT for other I/O standards.

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

  • 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 240 Ω resistor.
  • The RZQ pin shares the same VCCIO_PIO 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.
  • Only the 1.2 V VCCIO_PIO bank can use the OCT calibration block.