EP1SGX10C Datasheet, PDF (189/262 Pages) Altera Corporation – StratixGX FPGA Family

Configuration
There are two remote configuration modes: remote and local
configuration. Designers can use the remote update configuration mode
for all three configuration modes: serial, parallel synchronous, and
parallel asynchronous. Configuration devices (for example, EPC16
devices) only support serial and parallel synchronous modes.
Asynchronous parallel mode allows remote updates when an intelligent
host is used to configure the Stratix GX device. This host must support
page mode settings similar to an EPC16 device.
Remote Update Mode
When the Stratix GX device is first powered-up in remote update
programming mode, it loads the configuration located at page
address 000. The factory configuration should always be located at page
address 000, and should never be remotely updated. The factory
configuration contains the required logic to perform the following
operations:
■ Determine the page address/load location for the next application’s
configuration data
■ Recover from a previous configuration error
■ Receive new configuration data and write it into the configuration
device
The factory configuration is the default and takes control if an error
occurs while loading the application configuration.
While in the factory configuration, the factory-configuration logic
performs the following operations:
■ Loads a remote update-control register to determine the page
address of the new application configuration
■ Determines whether to enable a user watchdog timer for the
application configuration
■ Determines what the watchdog timer setting should be if it is
enabled
The user watchdog timer is a counter that must be continually reset
within a specific amount of time in the user mode of an application
configuration to ensure that valid configuration occurred during a remote
update. Only valid application configurations designed for remote
update can reset the user watchdog timer in user mode. If a valid
application configuration does not reset the user watchdog timer in a
specific amount of time, the timer updates a status register and loads the
factory configuration. The user watchdog timer is automatically disabled
for factory configurations.
Altera Corporation
189
Preliminary