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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
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3.3. Guidelines: Resetting the PLL
To reset the PLL, refer to the following guidelines:
- When changing the M counter, N counter, or loop filter settings, the I/O PLL may lose and regain lock. To maintain the appropriate phase relationship between the reference clock and output clocks, assert the areset signal to reset the I/O PLL after reconfiguration is complete. Altera recommends always resetting the I/O PLL after any reconfiguration operation to the M counter, N counter, or loop filter settings.
- When changing the C counter settings, you may lose the expected phase relationship between the C counters. Assert the areset signal after reconfiguration is complete to restore the expected phase relationship. Reset is not required if the phase relationships are not important to your application.
- Resetting the I/O PLL does not modify the counter or loop filter settings. However, resetting the I/O PLL undoes any dynamic phase shift operations that were performed. After the I/O PLL is reset, the phase shift on the C counters is restored to the originally programmed settings.