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. I/O PLL Reconfiguration
7. Document Revision History for the Clocking and PLL User Guide: Agilex™ 5 FPGAs and SoCs
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
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
6.1. Release Information for EMIF Calibration 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
6.7. Design Example
2.2.5.2. Locked
The locked signal port of the IP core for the I/O PLL is locked. The IOPLL IP core drives locked signal high when the PLL acquires lock.
The lock detection circuit provides a signal to the core logic. The signal indicates when the feedback clock locks onto the reference clock both in phase and frequency.
PLL loses lock if the input reference clock stops toggling. When PLL loses lock, the output of the PLL starts drifting out of the desired frequency. The downstream logic must be held inactive when PLL has lost lock.