EP2S90F1020C5 Datasheet, PDF (672/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

Remote System Upgrade Modes
When Stratix II or Stratix II GX devices successfully load the application
configuration, they enter into user mode. In user mode, the soft logic
(Nios processor or state machine and the remote communication
interface) assists the Stratix II or Stratix II GX 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.
Stratix II and Stratix II GX FPGAs support the remote update mode in the
AS, FPP, PS, and PPA configuration schemes. In the FPP, PS, and PPA
schemes, the MAX II device, microprocessor, or enhanced configuration
device should sample the PGM[2..0] outputs from the Stratix II or
Stratix II GX FPGA and transmit the appropriate configuration image. In
the AS scheme, the Stratix II or Stratix II GX device uses the page
addresses to read configuration data out of the serial configuration
device.
Local Update Mode
Local update mode is a simplified version of the remote update mode.
This feature allows systems to load an application configuration
immediately upon power up without loading the factory configuration
first. Local update mode does not require the factory configuration to
determine which application configuration to load, because only one
application configuration is allowed (at page address one
(PGM [2..0] = 001). You can update this application configuration
remotely. If an error occurs while loading the application configuration,
the factory configuration is automatically loaded.
Upon power up or nCONFIG assertion, the dedicated remote system
upgrade circuitry drives out “001” on the PGM[] pins selecting the
application configuration stored in page one. If the device encounters any
errors during the configuration cycle, the remote system upgrade
circuitry retries configuration by driving PGM[2..0] to zero
(PGM[2..0] = 000) to select the factory configuration image. The error
conditions that trigger a return to the factory configuration are:
■ An internal CRC error
■ An external error signal (nSTATUS detected low)
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Stratix II Device Handbook, Volume 2
Altera Corporation
January 2008