EP2AGX95EF29C6N Datasheet, PDF (339/380 Pages) Altera Corporation – Device Interfaces and Integration

Chapter 9: Configuration, Design Security, and Remote System Upgrades in Arria II Devices
Remote System Upgrade Mode
9–53
The factory image is user-designed and contains soft logic to:
■ Process any errors based on status information from the dedicated remote system
upgrade circuitry
■ Communicate with the remote host and receive new application configurations
and store this new configuration data in the local non-volatile memory device
■ Determine which application configuration is to be loaded into the Arria II device
■ Enable or disable the user watchdog timer and load its time-out value (optional)
■ Instruct the dedicated remote system upgrade circuitry to start a reconfiguration
cycle
Figure 9–24 shows the transitions between the factory and the application
configurations in remote update mode.
Figure 9–24. Transitions between Configurations in Remote Update Mode
Configuration Error
Power Up
Configuration
Error
Set Control Register
and Reconfigure
Factory
Configuration
(page 0)
Reload a
Different Application
Reload a
Different Application
Application 1
Configuration
Set Control Register
and Reconfigure
Application n
Configuration
Configuration Error
After power up or a configuration error, the factory configuration logic is loaded
automatically. The factory configuration also specifies whether to enable the user
watchdog timer for the application configuration and if enabled, to include the timer
setting information.
The user watchdog timer ensures that the application configuration is valid and
functional. The timer must be continually reset in a specific amount of time during
user mode operation of an application configuration. Only valid application
configurations contain the logic to reset the timer in user mode. This timer reset logic
must be part of a user-designed hardware and/or software health monitoring signal
that indicates error-free system operation. If the timer is not reset in a specific amount
of time; for example, the user application configuration detects a functional problem
or if the system hangs, the dedicated circuitry updates the remote system upgrade
status register, triggering the loading of the factory configuration.
July 2012 Altera Corporation
Arria II Device Handbook Volume 1: Device Interfaces and Integration