Configuration Schemes
SRAM configuration elements allow Cyclone II 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 the nCONFIGpin. The configuration process loads different
configuration data, reinitializes the device, and resumes user-mode
operation. You can perform in-field upgrades by distributing new
configuration files within the system or remotely.
A built-in weak pull-up resistor pulls all user I/O pins to VCCIO before
and during device configuration.
The configuration pins support 1.5-V/1.8-V or 2.5-V/3.3-V I/O
standards. The voltage level of the configuration output pins is
determined by the VCCIO of the bank where the pins reside. The bank
VCCIO selects whether the configuration inputs are 1.5-V, 1.8-V, 2.5-V, or
3.3-V compatible.
You can load the configuration data for a Cyclone II device with one of
three configuration schemes (see Table 3–4), chosen on the basis of the
target application. You can use a configuration device, intelligent
controller, or the JTAG port to configure a Cyclone II device. A low-cost
configuration device can automatically configure a Cyclone II device at
system power-up.
Configuration
Schemes
Multiple Cyclone II devices can be configured in any of the three
configuration schemes by connecting the configuration enable (nCE) and
configuration enable output (nCEO) pins on each device.
Table 3–4. Data Sources for Configuration
Configuration
Scheme
Data Source
Active serial (AS)
Low-cost serial configuration device
Passive serial (PS) Enhanced or EPC2 configuration device, MasterBlaster, ByteBlasterMV, ByteBlaster II or
USB Blaster download cable, or serial data source
JTAG
MasterBlaster, ByteBlasterMV, ByteBlaster II or USB Blaster download cable or a
microprocessor with a Jam or JBC file
f
For more information on configuration, see the Configuring Cyclone II
Devices chapter of the Cyclone II Handbook, Volume 2.
3–6
Altera Corporation
Cyclone II Device Handbook, Volume 1
February 2007
ALTERA [ ALTERA CORPORATION ]
