Stratix® 10 Clocking and PLL User Guide

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ID 683195
Date 7/11/2024
Public
Document Table of Contents
Document Table of Contents x
1. Stratix® 10 Clocking and PLL Overview 2. Stratix® 10 Clocking and PLL Architecture and Features 3. Stratix® 10 Clocking and PLL Design Considerations 4. Stratix® 10 Clocking and PLL Implementation Guides 5. Clock Control Intel® FPGA IP Core References 6. IOPLL Intel® FPGA IP Core References 7. IOPLL Reconfig Intel® FPGA IP Core References 8. Stratix® 10 Clocking and PLL User Guide Archives 9. Document Revision History for the Stratix® 10 Clocking and PLL User Guide
1. Stratix® 10 Clocking and PLL Overview x
1.1. Clock Networks Overview 1.2. PLLs Overview
2. Stratix® 10 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. Programmable Clock Routing Sources 2.1.4. Clock Control Features
2.1.1. Clock Network Architecture x
2.1.1.1. Clock Network Hierarchy 2.1.1.2. Clock Sector 2.1.1.3. Programmable Clock Routing
2.1.3. Programmable Clock Routing Sources x
2.1.3.1. Dedicated Clock Input Pins 2.1.3.2. Internal Logic 2.1.3.3. DPA Clock Outputs 2.1.3.4. Transceiver Clock Outputs 2.1.3.5. PLL Clock Outputs
2.1.4. Clock Control Features x
2.1.4.1. Clock Gating 2.1.4.2. Clock Divider 2.1.4.3. Dynamic Clock Switchover
2.1.4.1. Clock Gating x
2.1.4.1.1. Root Clock Gate 2.1.4.1.2. Sector Clock Gate 2.1.4.1.3. I/O PLL Clock Gate 2.1.4.1.4. LAB Clock Gate
2.2. PLLs Architecture and Features x
2.2.1. PLL Features 2.2.2. PLL Usage 2.2.3. PLL Architecture 2.2.4. PLL Control Signals 2.2.5. Clock Feedback Modes 2.2.6. Clock Multiplication and Division 2.2.7. Programmable Phase Shift 2.2.8. Programmable Duty Cycle 2.2.9. PLL Cascading 2.2.10. Clock Switchover 2.2.11. PLL Reconfiguration and Dynamic Phase Shift 2.2.12. PLL Calibration
2.2.4. PLL Control Signals x
2.2.4.1. Reset 2.2.4.2. Locked
2.2.5. Clock Feedback Modes x
2.2.5.1. Direct Compensation Mode 2.2.5.2. LVDS Compensation Mode 2.2.5.3. Source Synchronous Compensation Mode 2.2.5.4. Normal Compensation Mode 2.2.5.5. Zero-Delay Buffer Mode 2.2.5.6. External Feedback Mode
2.2.10. Clock Switchover x
2.2.10.1. Automatic Switchover 2.2.10.2. Automatic Switchover with Manual Override 2.2.10.3. Manual Clock Switchover
2.2.12. PLL Calibration x
2.2.12.1. Power-Up Calibration 2.2.12.2. User Calibration
3. Stratix® 10 Clocking and PLL Design Considerations x
3.1. Guideline: Clock Switchover 3.2. IP Core Constraints 3.3. Guideline: Resetting the PLL 3.4. Guideline: Configuration Constraints 3.5. Guideline: Timing Closure 3.6. Guideline: I/O PLL Reconfiguration 3.7. Guideline: I/O PLL Jitter Performance 3.8. Guideline: Clock Gating
4. Stratix® 10 Clocking and PLL Implementation Guides x
4.1. Clock Control Intel® FPGA IP Core 4.2. IOPLL Intel® FPGA IP Core 4.3. IOPLL Reconfig Stratix® 10 FPGA IP Core
4.1. Clock Control Intel® FPGA IP Core x
4.1.1. Release Information for Clock Control Intel® FPGA IP
4.2. IOPLL Intel® FPGA IP Core x
4.2.1. Release Information for IOPLL Intel® FPGA IP 4.2.2. .mif File Generation 4.2.3. IP-XACT File Generation 4.2.4. Implementing I/O PLL Dynamic Phase Shift in the IOPLL IP Core 4.2.5. Design Example
4.2.2. .mif File Generation x
4.2.2.1. Generating a New .mif File 4.2.2.2. Adding Configurations to Existing .mif File
4.2.3. IP-XACT File Generation x
4.2.3.1. Generating a New IP-XACT File
4.2.4. Implementing I/O PLL Dynamic Phase Shift in the IOPLL IP Core x
4.2.4.1. I/O PLL Dynamic Phase Shift Operation
4.2.5. Design Example x
4.2.5.1. Design Example: Dynamic Phase Shift Using IOPLL IP Core
4.3. IOPLL Reconfig Stratix® 10 FPGA IP Core x
4.3.1. Release Information for IOPLL Reconfig Intel® FPGA IP 4.3.2. Implementing I/O PLL Reconfiguration in the IOPLL Reconfig IP Core 4.3.3. IOPLL Reconfig IP Core Reconfiguration Modes 4.3.4. Design Examples
4.3.2. Implementing I/O PLL Reconfiguration in the IOPLL Reconfig IP Core x
4.3.2.1. Connectivity between the IOPLL and IOPLL Reconfig IP Cores 4.3.2.2. Connecting the IOPLL and IOPLL Reconfig IP Cores
4.3.3. IOPLL Reconfig IP Core Reconfiguration Modes x
4.3.3.1. .mif Streaming Reconfiguration 4.3.3.2. Advanced Mode Reconfiguration 4.3.3.3. Clock Gating Reconfiguration 4.3.3.4. Dynamic Phase Shift Reconfiguration
4.3.3.1. .mif Streaming Reconfiguration x
4.3.3.1.1. Recalibration Using .mif
4.3.3.2. Advanced Mode Reconfiguration x
4.3.3.2.1. Recalibration Using Advanced Mode
4.3.4. Design Examples x
4.3.4.1. Design Example 1: .mif Streaming Reconfiguration Using IOPLL Reconfig IP Core 4.3.4.2. Design Example 2: Advanced Mode Reconfiguration Using IOPLL Reconfig IP Core 4.3.4.3. Design Example 3: Clock Gating Reconfiguration Using IOPLL Reconfig IP Core 4.3.4.4. Design Example 4: Dynamic Phase Shift Using IOPLL Reconfig IP Core
5. Clock Control Intel® FPGA IP Core References x
5.1. Clock Control IP Core Parameters 5.2. Clock Control IP Core Ports and Signals
6. IOPLL Intel® FPGA IP Core References x
6.1. IOPLL IP Core Parameters 6.2. IOPLL IP Core Ports and Signals 6.3. Dynamic Phase Shift Ports in the IOPLL IP Core
6.1. IOPLL IP Core Parameters x
6.1.1. IOPLL IP Core Parameters - PLL Tab 6.1.2. IOPLL IP Core Parameters - Settings Tab 6.1.3. IOPLL IP Core Parameters - Cascading Tab 6.1.4. IOPLL IP Core Parameters - Dynamic Reconfiguration Tab 6.1.5. IOPLL IP Core Parameters - Advanced Parameters Tab
7. IOPLL Reconfig Intel® FPGA IP Core References x
7.1. Avalon® -MM Interface Ports in the IOPLL Reconfig IP Core 7.2. Address Bus and Data Bus Settings
7.2. Address Bus and Data Bus Settings x
7.2.1. Address Bus and Data Bus Settings for Advanced Mode Reconfiguration 7.2.2. Output Clock and the Corresponding Data Bit Setting for Clock Gating Reconfiguration 7.2.3. Data Bus Setting for Dynamic Phase Shift for IOPLL Reconfig IP Core
7.2.1. Address Bus and Data Bus Settings for Advanced Mode Reconfiguration x
7.2.1.1. Data Bus Setting for Bandwidth Control and Charge Pump 7.2.1.2. Data Bus Setting for Ripplecap
1. Stratix® 10 Clocking and PLL Overview
2. Stratix® 10 Clocking and PLL Architecture and Features
3. Stratix® 10 Clocking and PLL Design Considerations
4. Stratix® 10 Clocking and PLL Implementation Guides
5. Clock Control Intel® FPGA IP Core References
6. IOPLL Intel® FPGA IP Core References
7. IOPLL Reconfig Intel® FPGA IP Core References
8. Stratix® 10 Clocking and PLL User Guide Archives
9. Document Revision History for the Stratix® 10 Clocking and PLL User Guide

2.2.10.1. Automatic Switchover

Stratix® 10 I/O PLLs support a fully configurable clock switchover capability.

Figure 18. Automatic Clock Switchover Circuit Block DiagramThis figure shows a block diagram of the automatic switchover circuit built into the I/O PLL.


When the current reference clock is not present, the clock sense block automatically switches to the backup clock for I/O PLL reference. You can select a clock source as the backup clock by connecting it to the inclk1 port of the I/O PLL in your design.

The clock switchover circuit sends out three status signals—clkbad0, clkbad1, and activeclock—from the I/O PLL to implement a custom switchover circuit in the logic array.

In automatic switchover mode, the clkbad0 and clkbad1 signals indicate the status of the two clock inputs. When they are asserted, the clock sense block detects that the corresponding clock input has stopped toggling. These two signals are not valid if the frequency difference between inclk0 and inclk1 is greater than 20%.

The activeclock signal indicates which of the two clock inputs (inclk0 or inclk1) is being selected as the reference clock to the I/O PLL. When the frequency difference between the two clock inputs is more than 20%, the activeclock signal is the only valid status signal.

Use the switchover circuitry to automatically switch between inclk0 and inclk1 when the current reference clock to the I/O PLL stops toggling. You can switch back and forth between inclk0 and inclk1 any number of times when one of the two clocks fails and the other clock is available.

For example, in applications that require a redundant clock with the same frequency as the reference clock, the switchover state machine generates a signal (clksw) that controls the multiplexer select input. In this case, inclk1 becomes the reference clock for the I/O PLL.

When using automatic clock switchover mode, the following requirements must be satisfied:

  • Both clock inputs must be running when the FPGA is configured.
  • The period of the two clock inputs can differ by no more than 20%.
  • The input clocks must meet the input jitter specifications and I/O standard specifications.

Glitches in the input clock may be seen as a greater than 20% difference in frequency between the input clocks.

If the current clock input stops toggling while the other clock is also not toggling, switchover is not initiated and the clkbad[0..1] signals are not valid. If both clock inputs are not the same frequency, but their period difference is within 20%, the clock sense block detects when a clock stops toggling. However, the I/O PLL may lose lock after the switchover is completed and needs time to relock.

Note: You must reset the I/O PLL using the reset signal to maintain the phase relationships between the I/O PLL input and output clocks when using clock switchover.
Figure 19. Automatic Switchover After Loss of Clock DetectionThis figure shows an example waveform of the switchover feature in automatic switchover mode. In this example, the inclk0 signal is held low. After the inclk0 signal is held low for approximately two clock cycles, the clock sense circuitry drives the clkbad0 signal high. As the reference clock signal (inclk0) is not toggling, the switchover state machine controls the multiplexer through the extswitch signal to switch to the backup clock, inclk1.


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