Cyclone® V to Agilex™ 5 Device Migration Guide

ID 787947
Date 4/01/2024
Public
Document Table of Contents

2.6. PLL and Clock Network

PLL

Direct PLL migration between Cyclone® V and Agilex™ 5 devices is not possible because of the architectural differences between these two device families.

Agilex™ 5 devices contain the following types of I/O PLLs for core application:

  • I/O bank I/O PLL
  • Fabric-feeding I/O PLL

However, the Quartus® Prime software determines the I/O PLL type automatically based on the assigned location of the I/O PLL in the Assignment Editor.

The following table compares supported features between Cyclone® V and Agilex™ 5 devices:

Table 11.   Comparison of Supported Features Between Cyclone® V and Agilex™ 5 Devices
Features Cyclone® V Devices Agilex™ 5 Devices
Integer PLL Supported Supported
Fractional PLL Supported Not supported
C Counter Output 9
  • Four for I/O bank I/O PLL
  • Seven for Fabric-feeding I/O PLL
Dedicated External Clock Output Supported Supported 1
External Feedback Input Pin Supported Supported1
Source Synchronous Compensation Supported Supported
Direct Compensation Supported Supported
Normal Compensation Supported Supported
Zero-delay Buffer Compensation Supported Supported1
External Feedback Compensation Supported Supported1
LVDS Compensation Supported Supported1
Programmable Duty Cycle Supported Supported
Bandwidth Settings Low, Medium, High Automatically selected by the Quartus® Prime software
Dynamic Phase Shift
  • PLL reconfiguration IP
  • Altera PLL IP
PLL reconfiguration IP only
PLL Cascading Supported Supported 2
Output Counter Cascading Supported Not supported
Input Clock Switchover Supported Supported2

Due to the differences between Cyclone® V and Agilex™ 5 devices, you must identify if Agilex™ 5 devices support the PLL feature when planning to migrate from Cyclone® V devices. For example, Agilex™ 5 devices do not support fractional PLL, so if you need to use this feature for transceiver application, use transceiver PLL (TX PLL). For more information, refer to the Clocking and PLL User Guide: Agilex™ 5 FPGAs and SoCs.

Clock Network

The clock network architecture in Agilex™ 5 devices differ from Cyclone® V device architecture. Agilex™ 5 devices do not have Regional Clock (RCLK) and Periphery Clock (PCLK) networks. The Quartus® Prime Pro Edition software automatically determines the clock regions.

Agilex™ 5 devices use programmable clock tree synthesis for its core clocking function. Programmable clock tree synthesis uses dedicated clock tree routing and switching circuits. These dedicated circuits enable the Quartus® Prime Pro Edition software to create the clock trees your design requires.

1 Feature supported by I/O bank I/O PLL only. Not supported by Fabric-feeding I/O PLL.
2 Feature not supported by the Fabric-feeding I/O PLL located in the High Voltage I/O (HVIO) block.