EP2S90F1020C5 Datasheet, PDF (666/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

Functional Description
images. The factory image is a user-defined fall-back, or safe,
configuration and is responsible for administering remote updates in
conjunction with the dedicated circuitry. Application images implement
user-defined functionality in the target FPGA.
A remote system update involves storing a new application configuration
image or updating an existing one via the remote communication
interface. After an application configuration image is stored or updated
remotely, the user design in the FPGA initiates a reconfiguration cycle
with the new image. Any errors during or after this cycle are detected by
the dedicated remote system upgrade circuitry and cause the FPGA to
automatically revert to the factory image. The factory image then
performs error processing and recovery. While error processing
functionality is limited to the factory configuration, both factory and
application configurations can download and store remote updates and
initiate system reconfiguration.
Stratix II and Stratix II GX FPGAs select between the different
configuration images stored in the system configuration memory using
the page address pins or start address registers. A page is a section of the
configuration memory space that contains one configuration image for
each FPGA in the system. One page stores one system configuration,
regardless of the number of FPGAs in the system.
Page address pins select the configuration image within an enhanced
configuration device or flash memory (MAX II device or microprocessor
setup). Page start address registers are used when Stratix II and
Stratix II GX FPGAs are configured in AS mode with serial configuration
devices. Figure 8–3 illustrates page mode operation in Stratix II and
Stratix II GX FPGAs.
8–6
Stratix II Device Handbook, Volume 2
Altera Corporation
January 2008