Stratix® V Device Handbook: Volume 1: Device Interfaces and Integration

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ID 683665
Date 10/18/2023
Public
Document Table of Contents
Document Table of Contents x
1. Logic Array Blocks and Adaptive Logic Modules in Stratix V Devices 2. Embedded Memory Blocks in Stratix V Devices 3. Variable Precision DSP Blocks in Stratix V Devices 4. Clock Networks and PLLs in Stratix V Devices 5. I/O Features in Stratix V Devices 6. High-Speed Differential I/O Interfaces and DPA in Stratix® V Devices 7. External Memory Interfaces in Stratix V Devices 8. Configuration, Design Security, and Remote System Upgrades in Stratix V Devices 9. SEU Mitigation for Stratix V Devices 10. JTAG Boundary-Scan Testing in Stratix V Devices 11. Power Management in Stratix V Devices
1. Logic Array Blocks and Adaptive Logic Modules in Stratix V Devices x
1.1. LAB 1.2. ALM Operating Modes 1.3. LAB Power Management Techniques 1.4. Logic Array Blocks and Adaptive Logic Modules in Stratix V Devices Revision History
1.1. LAB x
1.1.1. MLAB 1.1.2. Local and Direct Link Interconnects 1.1.3. Shared Arithmetic Chain and Carry Chain Interconnects 1.1.4. LAB Control Signals 1.1.5. ALM Resources 1.1.6. ALM Output
1.2. ALM Operating Modes x
1.2.1. Normal Mode 1.2.2. Extended LUT Mode 1.2.3. Arithmetic Mode 1.2.4. Shared Arithmetic Mode
2. Embedded Memory Blocks in Stratix V Devices x
2.1. Types of Embedded Memory 2.2. Embedded Memory Design Guidelines for Stratix V Devices 2.3. Embedded Memory Features 2.4. Embedded Memory Modes 2.5. Embedded Memory Clocking Modes 2.6. Parity Bit in Memory Blocks 2.7. Byte Enable in Embedded Memory Blocks 2.8. Memory Blocks Packed Mode Support 2.9. Memory Blocks Address Clock Enable Support 2.10. Memory Blocks Asynchronous Clear 2.11. Memory Blocks Error Correction Code Support 2.12. Embedded Memory Blocks in Stratix V Devices Revision History
2.1. Types of Embedded Memory x
2.1.1. Embedded Memory Capacity in Stratix V Devices
2.2. Embedded Memory Design Guidelines for Stratix V Devices x
2.2.1. Guideline: Consider the Memory Block Selection 2.2.2. Guideline: Implement External Conflict Resolution 2.2.3. Guideline: Customize Read-During-Write Behavior 2.2.4. Guideline: Consider Power-Up State and Memory Initialization 2.2.5. Guideline: Control Clocking to Reduce Power Consumption
2.2.3. Guideline: Customize Read-During-Write Behavior x
2.2.3.1. Same-Port Read-During-Write Mode 2.2.3.2. Mixed-Port Read-During-Write Mode
2.3. Embedded Memory Features x
2.3.1. Embedded Memory Configurations 2.3.2. Mixed-Width Port Configurations
2.3.2. Mixed-Width Port Configurations x
2.3.2.1. M20K Blocks Mixed-Width Configurations
2.5. Embedded Memory Clocking Modes x
2.5.1. Clocking Modes for Each Memory Mode 2.5.2. Asynchronous Clears in Clocking Modes 2.5.3. Output Read Data in Simultaneous Read/Write 2.5.4. Independent Clock Enables in Clocking Modes
2.5.1. Clocking Modes for Each Memory Mode x
2.5.1.1. Single Clock Mode 2.5.1.2. Read/Write Clock Mode 2.5.1.3. Input/Output Clock Mode 2.5.1.4. Independent Clock Mode
2.7. Byte Enable in Embedded Memory Blocks x
2.7.1. Byte Enable Controls in Memory Blocks 2.7.2. Data Byte Output 2.7.3. RAM Blocks Operations
2.11. Memory Blocks Error Correction Code Support x
2.11.1. Error Correction Code Truth Table
3. Variable Precision DSP Blocks in Stratix V Devices x
3.1. Features 3.2. Supported Operational Modes in Stratix V Devices 3.3. Resources 3.4. Design Considerations 3.5. Block Architecture 3.6. Operational Mode Descriptions 3.7. Variable Precision DSP Blocks in Stratix V Devices Revision History
3.4. Design Considerations x
3.4.1. Operational Modes 3.4.2. Internal Coefficient and Pre-Adder 3.4.3. Accumulator 3.4.4. Chainout Adder
3.5. Block Architecture x
3.5.1. Input Register Bank 3.5.2. Pre-Adder 3.5.3. Internal Coefficient 3.5.4. Multipliers 3.5.5. Accumulator and Chainout Adder 3.5.6. Systolic Registers 3.5.7. Output Register Bank
3.6. Operational Mode Descriptions x
3.6.1. Independent Multiplier Mode 3.6.2. Independent Complex Multiplier Mode 3.6.3. Multiplier Adder Sum Mode 3.6.4. Sum of Square Mode 3.6.5. 18 x 18 Multiplication Summed with 36-Bit Input Mode 3.6.6. Systolic FIR Mode 3.6.7. Variable Precision DSP Block Control Signals
3.6.1. Independent Multiplier Mode x
3.6.1.1. 9 x 9 Independent Multiplier 3.6.1.2. 18 x 18 Independent Multiplier 3.6.1.3. 16 x 16 Independent Multiplier or 18 x 18 Independent Partial Multiplier 3.6.1.4. 27 x 27 Independent Multiplier 3.6.1.5. 36 x 18 Independent Multiplier 3.6.1.6. 36-Bit Independent Multiplier
3.6.2. Independent Complex Multiplier Mode x
3.6.2.1. 18 x 18 Complex Multiplier 3.6.2.2. 18 x 25 Complex Multiplier 3.6.2.3. 27 x 27 Complex Multiplier
3.6.3. Multiplier Adder Sum Mode x
3.6.3.1. One Sum of Two 18 x 18 Multipliers or Two 16 x 16 Multipliers 3.6.3.2. One Sum of Two 27 x 27 Multipliers 3.6.3.3. One Sum of Two 36 x 18 Multipliers 3.6.3.4. One Sum of Four 18 x 18 Multipliers
3.6.6. Systolic FIR Mode x
3.6.6.1. 18-Bit Systolic FIR Mode 3.6.6.2. 27-Bit Systolic FIR Mode
4. Clock Networks and PLLs in Stratix V Devices x
4.1. Clock Networks 4.2. Stratix V PLLs 4.3. Clock Networks and PLLs in Stratix V Devices Revision History
4.1. Clock Networks x
4.1.1. Clock Resources in Stratix® V Devices 4.1.2. Types of Clock Networks 4.1.3. Clock Sources Per Quadrant 4.1.4. Types of Clock Regions 4.1.5. Clock Network Sources 4.1.6. Clock Output Connections 4.1.7. Clock Control Block 4.1.8. Clock Power Down 4.1.9. Clock Enable Signals
4.1.2. Types of Clock Networks x
4.1.2.1. Global Clock Networks 4.1.2.2. Regional Clock Networks 4.1.2.3. Periphery Clock Networks
4.1.4. Types of Clock Regions x
4.1.4.1. Entire Device Clock Region 4.1.4.2. Regional Clock Region 4.1.4.3. Dual-Regional Clock Region
4.1.5. Clock Network Sources x
4.1.5.1. Dedicated Clock Input Pins 4.1.5.2. Internal Logic 4.1.5.3. DPA Outputs 4.1.5.4. HSSI Outputs 4.1.5.5. PLL Clock Outputs 4.1.5.6. Clock Input Pin Connections to GCLK and RCLK Networks
4.1.7. Clock Control Block x
4.1.7.1. Pin Mapping in Stratix V Devices 4.1.7.2. GCLK Control Block 4.1.7.3. RCLK Control Block 4.1.7.4. PCLK Control Block 4.1.7.5. External PLL Clock Output Control Block
4.2. Stratix V PLLs x
4.2.1. PLL Physical Counters in Stratix V Devices 4.2.2. PLL Locations in Stratix® V Devices 4.2.3. PLL Migration Guidelines 4.2.4. Fractional PLL Architecture 4.2.5. PLL Cascading 4.2.6. PLL External Clock I/O Pins 4.2.7. PLL Control Signals 4.2.8. Clock Feedback Modes 4.2.9. Clock Multiplication and Division 4.2.10. Programmable Phase Shift 4.2.11. Programmable Duty Cycle 4.2.12. Clock Switchover 4.2.13. PLL Reconfiguration and Dynamic Phase Shift
4.2.4. Fractional PLL Architecture x
4.2.4.1. Fractional PLL Usage
4.2.7. PLL Control Signals x
4.2.7.1. areset 4.2.7.2. locked
4.2.8. Clock Feedback Modes x
4.2.8.1. Source Synchronous Mode 4.2.8.2. LVDS Compensation Mode 4.2.8.3. Direct Mode 4.2.8.4. Normal Compensation Mode 4.2.8.5. Zero-Delay Buffer Mode 4.2.8.6. External Feedback Mode 4.2.8.7. Multiple PLLs in Normal Mode and Source Synchronous Mode
4.2.12. Clock Switchover x
4.2.12.1. Automatic Switchover 4.2.12.2. Automatic Switchover with Manual Override 4.2.12.3. Manual Clock Switchover 4.2.12.4. Guidelines
5. I/O Features in Stratix V Devices x
5.1. I/O Standards Support in Stratix V Devices 5.2. I/O Design Guidelines for Stratix V Devices 5.3. I/O Banks in Stratix® V Devices 5.4. I/O Banks Groups in Stratix V Devices 5.5. I/O Element Structure in Stratix V Devices 5.6. Programmable IOE Features in Stratix® V Devices 5.7. On-Chip I/O Termination in Stratix® V Devices 5.8. I/O Termination Schemes for Stratix® V Devices 5.9. I/O Features in Stratix V Devices Revision History
5.1. I/O Standards Support in Stratix V Devices x
5.1.1. I/O Standards Support in Stratix® V Devices 5.1.2. I/O Standards Voltage Levels in Stratix® V Devices 5.1.3. MultiVolt I/O Interface in Stratix® V Devices
5.2. I/O Design Guidelines for Stratix V Devices x
5.2.1. Mixing Voltage-Referenced and Non-Voltage-Referenced I/O Standards 5.2.2. Guideline: Use the Same VCCPD for All I/O Banks in a Group 5.2.3. Guideline: Observe Device Absolute Maximum Rating for 3.3 V Interfacing 5.2.4. Guideline: Use PLL Integer Mode for LVDS Applications
5.2.1. Mixing Voltage-Referenced and Non-Voltage-Referenced I/O Standards x
5.2.1.1. Non-Voltage-Referenced I/O Standards 5.2.1.2. Voltage-Referenced I/O Standards 5.2.1.3. Mixing Voltage-Referenced and Non-Voltage Referenced I/O Standards
5.4. I/O Banks Groups in Stratix V Devices x
5.4.1. Modular I/O Banks for Stratix® V E Devices 5.4.2. Modular I/O Banks for Stratix® V GX Devices 5.4.3. Modular I/O Banks for Stratix® V GS Devices 5.4.4. Modular I/O Banks for Stratix® V GT Devices
5.5. I/O Element Structure in Stratix V Devices x
5.5.1. I/O Buffer and Registers in Stratix V Devices 5.5.2. External Memory Interfaces 5.5.3. High-Speed Differential I/O with DPA Support
5.6. Programmable IOE Features in Stratix® V Devices x
5.6.1. Programmable Current Strength 5.6.2. Programmable Output Slew Rate Control 5.6.3. Programmable IOE Delay 5.6.4. Programmable Output Buffer Delay 5.6.5. Programmable Pre-Emphasis 5.6.6. Programmable Differential Output Voltage 5.6.7. Open-Drain Output 5.6.8. Bus-Hold Circuitry 5.6.9. Pull-up Resistor
5.7. On-Chip I/O Termination in Stratix® V Devices x
5.7.1. RS OCT without Calibration in Stratix® V Devices 5.7.2. RS OCT with Calibration in Stratix® V Devices 5.7.3. RT OCT with Calibration in Stratix® V Devices 5.7.4. Dynamic OCT in Stratix® V Devices 5.7.5. LVDS Input RD OCT in Stratix V Devices 5.7.6. OCT Calibration Block in Stratix V Devices 5.7.7. OCT Calibration in Power-Up Mode 5.7.8. OCT Calibration in User Mode
5.7.6. OCT Calibration Block in Stratix V Devices x
5.7.6.1. Calibration Block Locations in Stratix® V Devices 5.7.6.2. Sharing an OCT Calibration Block on Multiple I/O Banks
5.7.6.2. Sharing an OCT Calibration Block on Multiple I/O Banks x
5.7.6.2.1. OCT Calibration Block Sharing Example
5.7.8. OCT Calibration in User Mode x
5.7.8.1. Example of Using Multiple OCT Calibration Blocks
5.8. I/O Termination Schemes for Stratix® V Devices x
5.8.1. Single-ended I/O Termination 5.8.2. Differential I/O Termination
5.8.2. Differential I/O Termination x
5.8.2.1. Differential HSTL, SSTL, and HSUL Termination 5.8.2.2. LVDS, RSDS, and Mini-LVDS Termination 5.8.2.3. Emulated LVDS, RSDS, and Mini-LVDS Termination 5.8.2.4. LVPECL Termination
6. High-Speed Differential I/O Interfaces and DPA in Stratix® V Devices x
6.1. Dedicated High-Speed Circuitries in Stratix® V Devices 6.2. High-Speed I/O Design Guidelines for Stratix® V Devices 6.3. Differential Transmitter in Stratix V Devices 6.4. Differential Receiver in Stratix V Devices 6.5. Source-Synchronous Timing Budget 6.6. High-Speed Differential I/O Interfaces and DPA in Stratix® V Devices Revision History
6.1. Dedicated High-Speed Circuitries in Stratix® V Devices x
6.1.1. SERDES and DPA Bank Locations in Stratix® V Devices 6.1.2. LVDS SERDES Circuitry 6.1.3. SERDES I/O Standards Support in Stratix® V Devices 6.1.4. True LVDS Buffers in Stratix® V Devices 6.1.5. Emulated LVDS Buffers in Stratix V Devices
6.2. High-Speed I/O Design Guidelines for Stratix® V Devices x
6.2.1. PLLs and Clocking for Stratix® V Devices 6.2.2. LVDS Interface with External PLL Mode 6.2.3. Pin Placement Guidelines for DPA Differential Channels
6.2.1. PLLs and Clocking for Stratix® V Devices x
6.2.1.1. Guideline: Use PLLs in Integer PLL Mode for LVDS 6.2.1.2. Guideline: Use High-Speed Clock from PLL to Clock LVDS SERDES Only
6.2.2. LVDS Interface with External PLL Mode x
6.2.2.1. Altera_PLL Signal Interface with ALTLVDS IP Core 6.2.2.2. Altera_PLL Parameter Values for External PLL Mode 6.2.2.3. Connection between Altera_PLL and ALTLVDS
6.2.3. Pin Placement Guidelines for DPA Differential Channels x
6.2.3.1. Guideline: Using DPA-Enabled Differential Channels 6.2.3.2. Guideline: Using DPA-Disabled Differential Channels
6.3. Differential Transmitter in Stratix V Devices x
6.3.1. Transmitter Blocks 6.3.2. Transmitter Clocking 6.3.3. Serializer Bypass for DDR and SDR Operations 6.3.4. Programmable Differential Output Voltage 6.3.5. Programmable Pre-Emphasis
6.4. Differential Receiver in Stratix V Devices x
6.4.1. Receiver Blocks in Stratix V Devices 6.4.2. Receiver Modes in Stratix V Devices 6.4.3. Receiver Clocking for Stratix V Devices 6.4.4. Differential I/O Termination for Stratix V Devices
6.4.1. Receiver Blocks in Stratix V Devices x
6.4.1.1. DPA Block 6.4.1.2. Synchronizer 6.4.1.3. Data Realignment Block (Bit Slip) 6.4.1.4. Deserializer
6.4.2. Receiver Modes in Stratix V Devices x
6.4.2.1. Non-DPA Mode 6.4.2.2. DPA Mode 6.4.2.3. Soft-CDR Mode
6.5. Source-Synchronous Timing Budget x
6.5.1. Differential Data Orientation 6.5.2. Differential I/O Bit Position 6.5.3. Transmitter Channel-to-Channel Skew 6.5.4. Receiver Skew Margin for Non-DPA Mode
6.5.2. Differential I/O Bit Position x
6.5.2.1. Differential Bit Naming Conventions
6.5.4. Receiver Skew Margin for Non-DPA Mode x
6.5.4.1. Assigning Input Delay to LVDS Receiver Using Timing Analyzer
7. External Memory Interfaces in Stratix V Devices x
7.1. External Memory Performance 7.2. Memory Interface Pin Support in Stratix V Devices 7.3. External Memory Interface Features in Stratix V Devices 7.4. External Memory Interfaces in Stratix V Devices Revision History
7.2. Memory Interface Pin Support in Stratix V Devices x
7.2.1. Guideline: Using DQ/DQS Pins 7.2.2. DQ/DQS Bus Mode Pins for Stratix® V Devices 7.2.3. DQ/DQS Groups in Stratix V E 7.2.4. DQ/DQS Groups in Stratix V GX 7.2.5. DQ/DQS Groups in Stratix V GS 7.2.6. DQ/DQS Groups in Stratix V GT
7.3. External Memory Interface Features in Stratix V Devices x
7.3.1. UniPHY IP 7.3.2. External Memory Interface Datapath 7.3.3. DQS Phase-Shift Circuitry 7.3.4. Phase Offset Control 7.3.5. PHY Clock (PHYCLK) Networks 7.3.6. DQS Logic Block 7.3.7. Leveling Circuitry 7.3.8. Dynamic OCT Control 7.3.9. IOE Registers 7.3.10. Delay Chains 7.3.11. I/O and DQS Configuration Blocks
7.3.3. DQS Phase-Shift Circuitry x
7.3.3.1. Delay-Locked Loop 7.3.3.2. DLL Reference Clock Input for Stratix V Devices 7.3.3.3. DQS Phase-Shift
7.3.6. DQS Logic Block x
7.3.6.1. Update Enable Circuitry 7.3.6.2. DQS Delay Chain 7.3.6.3. DQS Postamble Circuitry 7.3.6.4. Half Data Rate Block
7.3.9. IOE Registers x
7.3.9.1. Input Registers 7.3.9.2. Output Registers
8. Configuration, Design Security, and Remote System Upgrades in Stratix V Devices x
8.1. Enhanced Configuration and Configuration via Protocol 8.2. MSEL Pin Settings 8.3. Configuration Sequence 8.4. Configuration Timing Waveforms 8.5. Device Configuration Pins 8.6. Fast Passive Parallel Configuration 8.7. Active Serial Configuration 8.8. Using EPCS and EPCQ Devices 8.9. Passive Serial Configuration 8.10. JTAG Configuration 8.11. Configuration Data Compression 8.12. Remote System Upgrades 8.13. Design Security 8.14. Configuration, Design Security, and Remote System Upgrades in Stratix V Devices Revision History
8.3. Configuration Sequence x
8.3.1. Power Up 8.3.2. Reset 8.3.3. Configuration 8.3.4. Configuration Error Handling 8.3.5. Initialization 8.3.6. User Mode
8.4. Configuration Timing Waveforms x
8.4.1. FPP Configuration Timing 8.4.2. AS Configuration Timing 8.4.3. PS Configuration Timing
8.5. Device Configuration Pins x
8.5.1. I/O Standards and Drive Strength for Configuration Pins 8.5.2. Configuration Pin Options in the Intel® Quartus® Prime Software
8.6. Fast Passive Parallel Configuration x
8.6.1. Fast Passive Parallel Single-Device Configuration 8.6.2. Fast Passive Parallel Multi-Device Configuration 8.6.3. Transmitting Configuration Data
8.6.2. Fast Passive Parallel Multi-Device Configuration x
8.6.2.1. Pin Connections and Guidelines 8.6.2.2. Using Multiple Configuration Data 8.6.2.3. Using One Configuration Data
8.7. Active Serial Configuration x
8.7.1. DATA Clock (DCLK) 8.7.2. Active Serial Single-Device Configuration 8.7.3. Active Serial Multi-Device Configuration 8.7.4. Estimating the Active Serial Configuration Time
8.7.3. Active Serial Multi-Device Configuration x
8.7.3.1. Pin Connections and Guidelines 8.7.3.2. Using Multiple Configuration Data
8.8. Using EPCS and EPCQ Devices x
8.8.1. Controlling EPCS and EPCQ Devices 8.8.2. Trace Length and Loading Guideline 8.8.3. Programming EPCS and EPCQ Devices
8.8.3. Programming EPCS and EPCQ Devices x
8.8.3.1. Programming EPCS Using the JTAG Interface 8.8.3.2. Programming EPCQ Using the JTAG Interface 8.8.3.3. Programming EPCS Using the Active Serial Interface 8.8.3.4. Programming EPCQ Using the Active Serial Interface
8.9. Passive Serial Configuration x
8.9.1. Passive Serial Single-Device Configuration Using an External Host 8.9.2. Passive Serial Single-Device Configuration Using an Altera Download Cable 8.9.3. Passive Serial Multi-Device Configuration
8.9.3. Passive Serial Multi-Device Configuration x
8.9.3.1. Pin Connections and Guidelines 8.9.3.2. Using Multiple Configuration Data 8.9.3.3. Using One Configuration Data 8.9.3.4. Using PC Host and Download Cable
8.10. JTAG Configuration x
8.10.1. JTAG Single-Device Configuration 8.10.2. JTAG Multi-Device Configuration 8.10.3. CONFIG_IO JTAG Instruction
8.10.2. JTAG Multi-Device Configuration x
8.10.2.1. Pin Connections and Guidelines 8.10.2.2. Using a Download Cable
8.11. Configuration Data Compression x
8.11.1. Enabling Compression Before Design Compilation 8.11.2. Enabling Compression After Design Compilation 8.11.3. Using Compression in Multi-Device Configuration
8.12. Remote System Upgrades x
8.12.1. Configuration Images 8.12.2. Configuration Sequence in the Remote Update Mode 8.12.3. Remote System Upgrade Circuitry 8.12.4. Enabling Remote System Upgrade Circuitry 8.12.5. Remote System Upgrade Registers 8.12.6. Remote System Upgrade State Machine 8.12.7. User Watchdog Timer
8.12.5. Remote System Upgrade Registers x
8.12.5.1. Control Register 8.12.5.2. Status Register
8.13. Design Security x
8.13.1. Altera Unique Chip ID IP Core 8.13.2. JTAG Secure Mode 8.13.3. Security Key Types 8.13.4. Security Modes 8.13.5. Design Security Implementation Steps
9. SEU Mitigation for Stratix V Devices x
9.1. Error Detection Features 9.2. Configuration Error Detection 9.3. User Mode Error Detection 9.4. Internal Scrubbing 9.5. Specifications 9.6. Using Error Detection Features in User Mode 9.7. SEU Mitigation for Stratix V Devices Revision History
9.5. Specifications x
9.5.1. Minimum EMR Update Interval 9.5.2. Error Detection Frequency 9.5.3. CRC Calculation Time For Entire Device
9.6. Using Error Detection Features in User Mode x
9.6.1. Enabling Error Detection and Internal Scrubbing 9.6.2. CRC_ERROR Pin 9.6.3. Error Detection Registers 9.6.4. Error Detection Process 9.6.5. Testing the Error Detection Block
10. JTAG Boundary-Scan Testing in Stratix V Devices x
10.1. BST Operation Control 10.2. I/O Voltage for JTAG Operation 10.3. Performing BST 10.4. Enabling and Disabling IEEE Std. 1149.1 BST Circuitry 10.5. Guidelines for IEEE Std. 1149.1 Boundary-Scan Testing 10.6. IEEE Std. 1149.1 Boundary-Scan Register 10.7. IEEE Std. 1149.6 Boundary-Scan Register 10.8. JTAG Boundary-Scan Testing inStratix V Devices Revision History
10.1. BST Operation Control x
10.1.1. IDCODE 10.1.2. Supported JTAG Instruction 10.1.3. JTAG Secure Mode 10.1.4. JTAG Private Instruction
10.6. IEEE Std. 1149.1 Boundary-Scan Register x
10.6.1. Boundary-Scan Cells of a Stratix V Device I/O Pin
11. Power Management in Stratix V Devices x
11.1. Power Consumption 11.2. Programmable Power Technology 11.3. Temperature Sensing Diode 11.4. Hot-Socketing Feature 11.5. Hot-Socketing Implementation 11.6. Power-Up Sequence 11.7. Power-On Reset Circuitry 11.8. Power Management in Stratix V Devices Revision History
11.1. Power Consumption x
11.1.1. Dynamic Power Equation
11.3. Temperature Sensing Diode x
11.3.1. Internal Temperature Sensing Diode 11.3.2. External Temperature Sensing Diode
11.7. Power-On Reset Circuitry x
11.7.1. Power Supplies Monitored and Not Monitored by the POR Circuitry
1. Logic Array Blocks and Adaptive Logic Modules in Stratix V Devices
2. Embedded Memory Blocks in Stratix V Devices
3. Variable Precision DSP Blocks in Stratix V Devices
4. Clock Networks and PLLs in Stratix V Devices
5. I/O Features in Stratix V Devices
6. High-Speed Differential I/O Interfaces and DPA in Stratix® V Devices
7. External Memory Interfaces in Stratix V Devices
8. Configuration, Design Security, and Remote System Upgrades in Stratix V Devices
9. SEU Mitigation for Stratix V Devices
10. JTAG Boundary-Scan Testing in Stratix V Devices
11. Power Management in Stratix V Devices

4.2.12.1. Automatic Switchover

Stratix® V PLLs support a fully configurable clock switchover capability.

Figure 83. Automatic Clock Switchover Circuit Block DiagramThis figure shows a block diagram of the automatic switchover circuit built into the PLL.


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

The clock switchover circuit sends out three status signals—clkbad[0], clkbad[1], and activeclock—from the PLL to implement a custom switchover circuit in the logic array.

In automatic switchover mode, the clkbad[0] and clkbad[1] 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 PLL. When the frequency difference between the two clock inputs is more than 20%, the activeclock signal is the only valid status signal.

Note: Glitches in the input clock may cause the frequency difference between the input clocks to be more than 20%.

Use the switchover circuitry to automatically switch between inclk0 and inclk1 when the current reference clock to the 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 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%.

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 PLL may lose lock after the switchover is completed and needs time to relock.

Note: Altera recommends resetting the PLL using the areset signal to maintain the phase relationships between the PLL input and output clocks when using clock switchover.
Figure 84. 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 stuck low. After the inclk0 signal is stuck at low for approximately two clock cycles, the clock sense circuitry drives the clkbad[0] signal high. Since the reference clock signal is not toggling, the switchover state machine controls the multiplexer through the extswitch signal to switch to the backup clock, inclk1.


Level Two Title