Configuration and Testing
input buffer. The VCCSEL input pin selects which input buffer is used. The
3.3-V/2.5-V input buffer is powered by VCCPD, while the 1.8-V/1.5-V
input buffer is powered by VCCIO
.
VCCSEL is sampled during power up. Therefore, the VCCSEL setting cannot
change on-the-fly or during a reconfiguration. The VCCSEL input buffer is
powered by VCCINT and must be hard-wired to VCCPD or ground. A logic
high VCCSEL connection selects the 1.8-V/1.5-V input buffer, and a logic
low selects the 3.3-V/2.5-V input buffer. VCCSEL should be set to comply
with the logic levels driven out of the configuration device or MAX II
microprocessor.
If the design must support configuration input voltages of 3.3 V/2.5 V, set
VCCSEL to a logic low. You can set the VCCIO voltage of the I/O bank that
contains the configuration inputs to any supported voltage. If the design
must support configuration input voltages of 1.8 V/1.5 V, set VCCSEL to a
logic high and the VCCIO of the bank that contains the configuration
inputs to 1.8 V/1.5 V.
f
For more information about multi-volt support, including information
about using TDOand nCEOin multi-volt systems, refer to the Arria GX
Architecture chapter in volume 1 of the Arria GX Device Handbook.
Configuration Schemes
You can load the configuration data for an Arria GX device with one of
five configuration schemes (refer to 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 an Arria GX device. A
configuration device can automatically configure an Arria GX device at
system power up.
You can configure multiple Arria GX devices in any of the five
configuration schemes by connecting the configuration enable (nCE) and
configuration enable output (nCEO) pins on each device. Arria GX FPGAs
offer the following:
■
■
Configuration data decompression to reduce configuration file
storage
Remote system upgrades for remotely updating Arria GX designs
3–6
Altera Corporation
Arria GX Device Handbook, Volume 1
May 2008
ALTERA [ ALTERA CORPORATION ]
