Clocking and PLL User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813671
Date 4/01/2024
Public
Document Table of Contents
Document Table of Contents x
1. Agilex™ 5 Clocking and PLL Overview 2. Agilex™ 5 Clocking and PLL Architecture and Features 3. Agilex™ 5 Clocking and PLL Design Considerations 4. Clock Control Intel® FPGA IP Core 5. IOPLL Intel® FPGA IP Core 6. Document Revision History for the Clocking and PLL User Guide: Agilex™ 5 FPGAs and SoCs
1. Agilex™ 5 Clocking and PLL Overview x
1.1. Clock Networks Overview 1.2. PLLs Overview
2. Agilex™ 5 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™ 5 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 Core Constraints 3.7. Guideline: Achieving 5% Duty Cycle for fOUT_EXT ≥ 300 MHz Using tx_outclk Port from LVDS SERDES Intel® FPGA IP
4. Clock Control Intel® FPGA IP Core x
4.1. Release Information for Clock Control Intel® FPGA IP 4.2. Clock Control IP Core Parameters 4.3. Clock Control IP Core Ports and Signals
5. IOPLL Intel® FPGA IP Core x
5.1. Release Information for IOPLL Intel® FPGA IP Core 5.2. IOPLL IP Core Parameters 5.3. IOPLL IP Core Ports and Signals
5.2. IOPLL IP Core Parameters x
5.2.1. IOPLL IP Core Parameters - PLL Tab 5.2.2. IOPLL IP Core Parameters - Settings Tab 5.2.3. IOPLL IP Core Parameters - Cascading Tab 5.2.4. IOPLL IP Core Parameters - Advanced Parameters Tab
1. Agilex™ 5 Clocking and PLL Overview
2. Agilex™ 5 Clocking and PLL Architecture and Features
3. Agilex™ 5 Clocking and PLL Design Considerations
4. Clock Control Intel® FPGA IP Core
5. IOPLL Intel® FPGA IP Core
6. Document Revision History for the Clocking and PLL User Guide: Agilex™ 5 FPGAs and SoCs

2.2.10. PLL Cascading

Agilex™ 5 devices support PLL-to-PLL cascading. You can cascade a maximum of two PLLs. PLL cascading synthesizes more output clock frequencies than a single PLL.

Agilex™ 5 devices support the following PLL-to-PLL cascading modes for I/O bank I/O PLL and I/O Bank Fabric-Feeding I/O PLL. HVIO fabric-feeding I/O PLL do not support cascading.
  • I/O Bank I/O-PLL-to-I/O Bank I/O-PLL cascading
  • I/O Bank I/O-PLL-to-I/O Bank fabric-feeding I/O-PLL cascading
  • I/O Bank fabric-feeding I/O-PLL-to I/O Bank I/O-PLL cascading
Cascading of PLLs can be done via two paths: via dedicated cascade path or via core clock fabric.
  • Cascading via dedicated cascade path—upstream I/O PLL and downstream I/O PLL must be in the same I/O column and are placed adjacently.
  • Cascading via core clock fabric—no restriction on locations of upstream and downstream I/O PLL.

The permit_cal input of the downstream I/O PLL must be connected to the locked output of the upstream I/O PLL in both PLL cascading modes.

The following figures show the connectivity required between the upstream and downstream I/O PLL for both the PLL cascading modes.

Figure 18. I/O-PLL-to-I/O-PLL Cascading Through Dedicated Cascade Path
Note: To set up an I/O bank I/O PLL as the upstream PLL, you must enable up to 6 or 7 counters as only C5 and C6 can be the cascade_out port. You can leave the unused counters disconnected.
Figure 19. I/O-PLL-to-I/O-PLL Cascading Through Core Clock Fabric
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