EP2SGX130GF1508C4 Datasheet, PDF (141/316 Pages) Altera Corporation – Section I. Stratix II GX Device Data Sheet

Stratix II GX Architecture
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On-Chip Parallel Termination with Calibration
Stratix II GX devices support on-chip parallel termination with
calibration for column I/O pins only. There is one calibration circuit for
the top I/O banks and one circuit for the bottom I/O banks. Each on-chip
parallel termination calibration circuit compares the total impedance of
each I/O buffer to the external 50-Ω resistors connected to the RUP and
RDN pins and dynamically enables or disables the transistors until they
match. Calibration occurs at the end of device configuration. Once the
calibration circuit finds the correct impedance, it powers down and stops
changing the characteristics of the drivers.
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On-chip parallel termination with calibration is only supported
for input pins.
For more information about on-chip termination supported by Stratix II
devices, refer to the Selectable I/O Standards in Stratix II & Stratix II GX
Devices chapter in volume 2 of the Stratix II GX Device Handbook.
For more information about tolerance specifications for on-chip
termination with calibration, refer to the DC & Switching Characteristics
chapter in volume 1 of the Stratix II GX Device Handbook.
MultiVolt I/O Interface
The Stratix II GX architecture supports the MultiVolt I/O interface feature
that allows Stratix II GX devices in all packages to interface with systems
of different supply voltages. The Stratix II GX VCCINT pins must always
be connected to a 1.2-V power supply. With a 1.2-V V_CCINT level, input
pins are 1.2-, 1.5-, 1.8-, 2.5-, and 3.3-V tolerant. The VCCIO pins can be
connected to either a 1.2-, 1.5-, 1.8-, 2.5-, or 3.3-V power supply,
depending on the output requirements. The output levels are compatible
with systems of the same voltage as the power supply (for example, when
VCCIO pins are connected to a 1.5-V power supply, the output levels are
compatible with 1.5-V systems). The Stratix II GX VCCPD power pins
must be connected to a 3.3-V power supply. These power pins are used to
supply the pre-driver power to the output buffers, which increases the
performance of the output pins. The VCCPD pins also power
configuration input pins and JTAG input pins.
Altera Corporation
October 2007
2–133
Stratix II GX Device Handbook, Volume 1