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

ID 772138
Date 3/22/2024
Document Table of Contents Single-Ended I/O Standards On-Chip Termination

Serial (RS) and parallel (RT) OCT provides I/O impedance matching and termination capabilities.

The OCT calibration circuit uses the impedance of the external resistor that is connected to the RZQ pin as reference. During calibration, the circuit continuously alters the impedance of the I/O buffer until the impedance reaches a predetermined ratio to the reference resistance.

The OCT with calibration feature is not supported in GPIO mode.

Table 10.  OCT Schemes Supported in M-Series Devices
Direction OCT Scheme
Output RS OCT with calibration
RS OCT without calibration
Input RT OCT with calibration
RT OCT without calibration
Bidirectional Dynamic RS and RT OCT