Clocking and PLL User Guide: Agilex™ 3 FPGAs and SoCs

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ID 847921
Date 4/07/2025
Public
Document Table of Contents
Document Table of Contents x
1. Agilex™ 3 Clocking and PLL Overview 2. Agilex™ 3 Clocking and PLL Architecture and Features 3. Agilex™ 3 Clocking and PLL Design Considerations 4. Clock Control Altera™ FPGA IP Core 5. IOPLL FPGA IP 6. I/O PLL Reconfiguration 7. Document Revision History for the Clocking and PLL User Guide: Agilex™ 3 FPGAs and SoCs
1. Agilex™ 3 Clocking and PLL Overview x
1.1. Clock Networks Overview 1.2. PLLs Overview
2. Agilex™ 3 Clocking and PLL Architecture and Features x
2.1. Clock Networks Architecture and Features 2.2. PLLs Architecture and Features
2.1. Clock Networks Architecture and Features x
2.1.1. Clock Network Architecture 2.1.2. Clock Resources 2.1.3. Clock Control Features
2.1.1. Clock Network Architecture x
2.1.1.1. Clock Network Hierarchy 2.1.1.2. Clock Sectors 2.1.1.3. Programmable Clock Routing
2.1.3. Clock Control Features x
2.1.3.1. Clock Gating 2.1.3.2. Clock Divider
2.1.3.1. Clock Gating x
2.1.3.1.1. Root Clock Gate 2.1.3.1.2. Sector Clock Gate 2.1.3.1.3. I/O PLL Clock Gate 2.1.3.1.4. LAB Clock Gate
2.2. PLLs Architecture and Features x
2.2.1. PLL Features 2.2.2. PLL Usage 2.2.3. PLL Locations 2.2.4. PLL Architecture 2.2.5. PLL Control Signals 2.2.6. PLL Feedback Modes 2.2.7. Clock Multiplication and Division 2.2.8. Programmable Phase Shift 2.2.9. Programmable Duty Cycle 2.2.10. PLL Cascading 2.2.11. PLL Input Clock Switchover 2.2.12. PLL Reconfiguration and Dynamic Phase Shift 2.2.13. PLL Calibration
2.2.5. PLL Control Signals x
2.2.5.1. Reset 2.2.5.2. Locked
2.2.6. PLL Feedback Modes x
2.2.6.1. Direct Compensation Mode 2.2.6.2. LVDS Compensation Mode 2.2.6.3. Source Synchronous Compensation Mode 2.2.6.4. Normal Compensation Mode 2.2.6.5. Zero-Delay Buffer Mode 2.2.6.6. External Feedback Mode
2.2.11. PLL Input Clock Switchover x
2.2.11.1. Automatic Switchover 2.2.11.2. Automatic Switchover with Manual Override 2.2.11.3. Manual Clock Switchover
2.2.13. PLL Calibration x
2.2.13.1. Power-Up Calibration 2.2.13.2. User Calibration 2.2.13.3. Static Phase Error Calibration
3. Agilex™ 3 Clocking and PLL Design Considerations x
3.1. Guidelines: Clock Switchover 3.2. Guidelines: Timing Closure 3.3. Guidelines: Resetting the PLL 3.4. Guidelines: Configuration Constraints 3.5. Clocking Constraints 3.6. IP Constraints 3.7. Guideline: Achieving 5% Duty Cycle for fOUT_EXT ≥ 300 MHz Using tx_outclk Port from LVDS SERDES IP
4. Clock Control Altera™ FPGA IP Core x
4.1. Release Information for Clock Control Altera™ FPGA IP 4.2. Clock Control Altera™ FPGA IP Parameters 4.3. Clock Control Altera™ FPGA IP Ports and Signals
5. IOPLL FPGA IP x
5.1. Release Information for IOPLL FPGA IP 5.2. IOPLL FPGA IP Parameters 5.3. IOPLL IP Ports and Signals
5.2. IOPLL FPGA IP Parameters x
5.2.1. IOPLL IP Parameters - PLL Tab 5.2.2. IOPLL IP Parameters - Settings Tab 5.2.3. IOPLL IP Parameters - Cascading Tab 5.2.4. IOPLL IP Parameters - Advanced Parameters Tab
6. I/O PLL Reconfiguration x
6.1. Release Information for EMIF Calibration FPGA IP 6.2. Implementing HSIO I/O PLL Reconfiguration using EMIF Calibration IP 6.3. Implementing HVIO I/O PLL Reconfiguration 6.4. Reconfiguration Guideline for I/O PLLs 6.5. Axilite Interface Ports in the EMIF Calibration IP 6.6. Address Bus and Data Bus Settings
6.2. Implementing HSIO I/O PLL Reconfiguration using EMIF Calibration IP x
6.2.1. Setting Up the IOPLL FPGA IP 6.2.2. Setting Up the EMIF Calibration FPGA IP 6.2.3. Connectivity Between IOPLL FPGA IP and EMIF Calibration IP
6.3. Implementing HVIO I/O PLL Reconfiguration x
6.3.1. Setting Up the IOPLL FPGA IP 6.3.2. Read and Write Operations
6.4. Reconfiguration Guideline for I/O PLLs x
6.4.1. Enabling Reconfiguration for The Desired I/O PLL 6.4.2. Clearing off Calibration Statuses 6.4.3. Reconfiguring The I/O PLL 6.4.4. Recalibration of I/O PLL 6.4.5. Clock Gating (Optional)
6.6. Address Bus and Data Bus Settings x
6.6.1. Divide Settings and the Corresponding Data Bit Setting for Reconfiguration 6.6.2. Data Bus Setting for Clock Gating Reconfiguration 6.6.3. Data Bus Setting For Charge Pump Current
1. Agilex™ 3 Clocking and PLL Overview
2. Agilex™ 3 Clocking and PLL Architecture and Features
3. Agilex™ 3 Clocking and PLL Design Considerations
4. Clock Control Altera™ FPGA IP Core
5. IOPLL FPGA IP
6. I/O PLL Reconfiguration
7. Document Revision History for the Clocking and PLL User Guide: Agilex™ 3 FPGAs and SoCs

2.1.3.2. Clock Divider

There is one clock divider per I/O bank and transceiver bank. The clock divider is a part of the periphery DCM block and is located close to the root clock gate. The outputs of the clock divider cannot be gated by the root clock gate in the same periphery DCM block. However, this limitation does not apply to the SCLK gate. The clock divider output in the periphery DCM block can drive a SCLK gate after going through the programmable clock routing.

The clock divider has three outputs as follows:

  • First output—passes through the input clock.
  • Second output—divides the input clock by two.
  • Third output—divides the input clock by four.

These three clock outputs are edge-aligned at the output of the clock divider.

Figure 7. Clock Divider Timing Diagram
Level Two Title