EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 347

• Manufacturer Part Number: EP3C16F256I7N
• Description: Cyclone III
• Manufacturer: Altera

Figure 12–3. Transitions Between Configurations in Remote Update Mode
Altera Corporation-Preliminary
March 2007
Configuration
Error
Power Up
Figure 12–3
configurations in remote update mode.
After power up or a configuration error, the factory configuration logic
writes the remote system upgrade control register to specify the address
of the application configuration to be loaded. The factory configuration
also specifies whether or not to enable the user watchdog timer for the
application configuration and, if enabled, specify the timer setting.
The user watchdog timer ensures that the application configuration is
valid and functional. After confirming the system is healthy, the
user-designed application configuration must reset the timer periodically
during user-mode operation of an application configuration. This timer
reset logic should be a user-designed hardware and/or software health
monitoring signal that indicates error-free system operation. If the user
application configuration detects a functional problem or if the system
hangs, the timer is not reset in time and the dedicated circuitry updates
the remote system upgrade status register, triggering the device to load
the factory configuration. The user watchdog timer is automatically
disabled for factory configurations.
1
Configuration
Factory
Only valid application configurations designed for remote
update mode include the logic to reset the timer in user mode.
shows the transitions between the factory and application
Set Control Register
Configuration Error
Configuration Error
and Reconfigure
Set Control Register
Reload a Different Application
and Reconfigure
Reload a Different Application
Remote System Upgrade With Cyclone III Devices
Cyclone III Device Handbook, Volume 1
Application 1
Configuration
Configuration
Application n
12–7