EP1SGX10C Datasheet, PDF (187/262 Pages) Altera Corporation – StratixGX FPGA Family

Configuration
or asynchronously. The interface also enables microprocessors to treat
Stratix GX devices as memory and configure them by writing to a virtual
memory location, making reconfiguration easy. After a Stratix GX device
has been configured, it can be reconfigured in-circuit by resetting the
device and loading new data. Real-time changes can be made during
system operation, enabling innovative reconfigurable computing
applications.
Operating Modes
The Stratix GX architecture uses SRAM configuration elements that
require configuration data to be loaded each time the circuit powers up.
The process of physically loading the SRAM data into the device is called
configuration. During initialization, which occurs immediately after
configuration, the device resets registers, enables I/O pins, and begins to
operate as a logic device. The I/O pins are tri-stated during power up,
and before and during configuration. Together, the configuration and
initialization processes are called command mode. Normal device
operation is called user mode.
A built-in weak pull-up resistor pulls all user I/O pins to V_CCIO before
and during device configuration.
SRAM configuration elements allow Stratix GX devices to be
reconfigured in-circuit by loading new configuration data into the device.
With real-time reconfiguration, the device is forced into command mode
with a device pin. The configuration process loads different configuration
data, reinitializes the device, and resumes user-mode operation.
Designers can perform in-field upgrades by distributing new
configuration files either within the system or remotely.
Configuration Schemes
Designers can load the configuration data for a Stratix GX device with
one of five configuration schemes (see Table 58), chosen on the basis of the
target application. Designers can use a configuration device, intelligent
controller, or the JTAG port to configure a Stratix GX device. A
configuration device can automatically configure a Stratix GX device at
system power-up.
Altera Corporation
187
Preliminary