GTS Transceiver PHY User Guide: Agilex™ 5 FPGAs and SoCs

ID 817660
Date 10/17/2025
Public
Document Table of Contents

3.3.6.5. PMA Configuration Rules for OTN Mode

You can implement the OTN mode by using the following configuration settings in the GTS PMA/FEC Direct PHY IP:
  1. In the Common Datapath Options select OTN for the PMA configuration rules setting.
  2. Configure the PMA data rate to match specific OTN line bit rate you are using.
  3. Ensure that the reference clocks; transmitter (TX PLL reference clock) and receiver (RX CDR reference clock), are set to the correct frequency to support the OTN line rate.
The OTN (PMA Direct) mode requires following configuration:
Table 35.  OTN (PMA Direct) Configuration Options
Parameter Value
PMA Configuration Rules

OTN

No. of PMA Lanes

1 for Agilex™ 5 E-Series group B devices.

4 for Agilex™ 5 E-Series group A and Agilex™ 5 D-Series devices.

1 for all Agilex™ 5 devices with FEC Direct mode.

Data Rate 1.3274G, 2.66G, 10.709G, 11.049G, 11.270G, 11.09G, 11.317G, 11.846G, 12.639G, 27.952493G (without FEC and PCS)
Datapath clocking mode PMA or System PLL
System PLL Frequency

322.265625-1000 MHz

OTN configuration rules support both System PLL and PMA clocking mode. If you select PMA clocking mode, this setting is not required.

PMA Mode Duplex

The OTN can also be used with FEC Direct mode. The OTN (FEC-Direct) mode requires the following configurations:

Table 36.  OTN Configuration for FEC-Direct
Parameter Value
Common Datapath Options
PMA Configuration Rules

Basic/OTN

No. of PMA Lanes

1 for all Agilex™ 5 devices.

PMA Data Rate 27.952493G
Datapath clocking mode System PLL
System PLL Frequency

322.265625-1000 MHz

PMA Mode Duplex
FEC Options
Enable FEC Enable
FEC Mode OTU25u RS (528,514)

You can also enable fractional mode (1 Lane/4 Lane) for OTN (PMA-Direct) mode and 1 Lane for OTN (FEC-Direct) mode. For more details, refer to PMA Primary PLL Configuration and the PMA Fractional Mode section under Clocking.