EP4SE360F35I4 Datasheet, PDF (391/432 Pages) Altera Corporation – This section provides a complete overview of all features relating to the Stratix IV device family, which is the most architecturlly advanced

Chapter 10: Configuration, Design Security, and Remote System Upgrades in Stratix IV Devices
Remote System Upgrade Mode
10–55
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 Stratix IV
device
■ Enable or disable the user watchdog timer and load its time-out value (optional)
■ Instruct the dedicated remote system upgrade circuitry to initiate a
reconfiguration cycle
Figure 10–24 shows the transitions between the factory and application
configurations in remote update mode.
Figure 10–24. 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 must specify 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 within 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.
September 2012 Altera Corporation
Stratix IV Device Handbook
Volume 1