EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 348

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

Remote System Upgrade With Cyclone III Devices
Dedicated
Remote System
Upgrade
Circuitry
12–8
Cyclone III Device Handbook, Volume 1
For more information about the user watchdog timer, refer to the
Watchdog Timer” on page
If there is an error while loading the application configuration, the remote
system upgrade status register is written by the Cyclone III device's
dedicated remote system upgrade circuitry, specifying the cause of the
reconfiguration. The following actions cause the remote system upgrade
status register to be written:
■
■
■
■
Cyclone III devices automatically load the factory configuration located
at address boot_address[23:0] = 24'b0 for the AS configuration
scheme, and default address boot_address[23:0] = 24'h010000
(or the updated address if the default address is changed) for the AP
configuration scheme. This user-designed factory configuration reads the
remote system upgrade status register to determine the reason for
reconfiguration. Then the factory configuration takes the appropriate
error recovery steps and writes to the remote system upgrade control
register to determine the next application configuration to be loaded.
When Cyclone III devices successfully load the application configuration,
they enter into user mode. In user mode, the soft logic (Nios II processor
or state machine and the remote communication interface) assists the
Cyclone III device in determining when a remote system update is
arriving. When a remote system update arrives, the soft logic receives the
incoming data, writes it to the configuration memory device, and triggers
the device to load the factory configuration. The factory configuration
reads the remote system upgrade status register, determines the valid
application configuration to load, writes the remote system upgrade
control register accordingly, and initiates system reconfiguration.
This section explains the implementation of the Cyclone III remote
system upgrade dedicated circuitry. The remote system upgrade
circuitry is implemented in hard logic. This dedicated circuitry interfaces
to the user-defined factory application configurations implemented in the
Cyclone III device logic array to provide the complete remote
configuration solution. The remote system upgrade circuitry contains the
remote system upgrade registers, a watchdog timer, and state machines
that control those components.
upgrade block's data path.
nSTATUS driven low externally
Internal CRC error
User watchdog timer timeout
A configuration reset (logic array nCONFIG signal or external
nCONFIG pin assertion)
12–16.
Figure 12–4
Altera Corporation-Preliminary
shows the remote system
March 2007
“User