EP2S90F1020C5 Datasheet, PDF (674/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

Dedicated Remote System Upgrade Circuitry
1 Local update mode is not supported in the AS configuration
scheme (with a serial configuration device).
Local update mode supports read access to the remote system upgrade
status register. The factory configuration image can use this error status
information to determine if a new application configuration must be
downloaded from the remote source. After a remote update, the user
design should assert the logic array configuration reset (nCONFIG) signal
to load the new application configuration.
The device does not support write access to the remote system upgrade
control register in local update mode. Write access is not required because
this mode only supports one application configuration (eliminating the
need to write in a page address) and does not support the user watchdog
timer (eliminating the need to enable or disable the timer or specify its
time-out value).
1 The user watchdog timer is disabled in local update mode.
1
Write access to the remote system upgrade control register is
disabled in local update mode. However, the device supports
read access to obtain error status information.
Dedicated
Remote System
Upgrade
Circuitry
This section explains the implementation of the Stratix II or Stratix II GX
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
FPGA logic array to provide the complete remote configuration solution.
The remote system upgrade circuitry contains the remote system upgrade
registers, a watchdog timer, and a state machine that controls those
components. Figure 8–6 shows the remote system upgrade block’s data
path.
8–14
Stratix II Device Handbook, Volume 2
Altera Corporation
January 2008