EP2C8T144I8N Datasheet, PDF (86/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

I/O Structure & Features
standards (e.g., SSTL-2) independently. If an I/O bank does not use
voltage-referenced standards, the VREF pins are available as user I/O
pins.
Each I/O bank can support multiple standards with the same V_CCIO for
input and output pins. For example, when V_CCIO is 3.3-V, a bank can
support LVTTL, LVCMOS, and 3.3-V PCI for inputs and outputs.
Voltage-referenced standards can be supported in an I/O bank using any
number of single-ended or differential standards as long as they use the
same V_REF and a compatible V_CCIO value.
MultiVolt I/O Interface
The Cyclone II architecture supports the MultiVolt I/O interface feature,
which allows Cyclone II devices in all packages to interface with systems
of different supply voltages. Cyclone II devices have one set of V_CC pins
(VCCINT) that power the internal device logic array and input buffers that
use the LVPECL, LVDS, HSTL, or SSTL I/O standards. Cyclone II devices
also have four or eight sets of VCC pins (VCCIO) that power the I/O
output drivers and input buffers that use the LVTTL, LVCMOS, or PCI
I/O standards.
The Cyclone II VCCINT pins must always be connected to a 1.2-V power
supply. If the V_CCINT level is 1.2 V, then input pins are 1.5-V, 1.8-V, 2.5-V,
and 3.3-V tolerant. The VCCIO pins can be connected to either a 1.5-V,
1.8-V, 2.5-V, 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 (i.e., when VCCIO pins are connected to a
1.5-V power supply, the output levels are compatible with 1.5-V systems).
When VCCIO pins are connected to a 3.3-V power supply, the output high
is 3.3-V and is compatible with 3.3-V systems. Table 2–20 summarizes
Cyclone II MultiVolt I/O support.
Table 2–20. Cyclone II MultiVolt I/O Support (Part 1 of 2)
V_CCIO (V)
1.5
1.8
2.5
1.5 V
v
v (4)
Input Signal
1.8 V
v
v
2.5 V
v (2)
v (2)
v
3.3 V
v (2)
v (2)
v
Note (1)
1.5 V
v
v (3)
v (5)
Output Signal
1.8 V
2.5 V
v
v (5)
v
3.3 V
2–60
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2007