Intel® MAX® 10 Clocking and PLL User Guide

ID 683047
Date 12/26/2023
Public
Document Table of Contents

6.1.4. Clock Switchover Parameter Settings

The parameter settings for clock switchover feature are located on the Clock switchover page of the Avalon ALTPLL Intel® FPGA IP parameter editor.

Table 18.  Clock Switchover Parameter Editor Settings
Parameter Value Description
Create an 'inclk1' input for a second input clock On or Off

Turn on this option to enable the switchover feature.

The inclk0 signal is by default the primary input clock signal of the Avalon ALTPLL Intel® FPGA IP.

Create a 'clkswitch' input to manually select between the input clocks Select this option for manual clock switchover mode.
Allow PLL to automatically control the switching between input clocks

Select this option for automatic clock switchover mode.

The automatic switchover is initiated during loss of lock or when the inclk0 signal stops toggling.

Create a 'clkswitch' input to dynamically control the switching between input clocks On or Off

Turn on this option for automatic clock switchover with manual override mode.

The automatic switchover is initiated during loss of lock or when the clkswitch signal is asserted.

Perform the input clock switchover after (number) input clock cycles On or Off

Turn on this option to specify the number of clock cycles to wait before the PLL performs the clock switchover.

The allowed number of clock cycles to wait is device-dependent.

Create an 'activeclock' output to indicate the input clock being used On or Off

Turn on this option to monitor which input clock signal is driving the PLL.

When the current clock signal is inclk0, the activeclock signal is low. When the current clock signal is inclk1, the activeclock signal is high.

Create a 'clkbad' output for each input clock On or Off

Turn on this option to monitor when the input clock signal has stopped toggling.

The clkbad0 signal monitors the inclk0 signal. The clkbad1 signal monitors the inclk1 signal.

The clkbad0 signal goes high when the inclk0 signal stops toggling. The clkbad1 signal goes high when the inclk1 signal stops toggling. The clkbad signals remain low when the input clock signals are toggling.