I/O Design Guidelines For Cyclone V Devices; Mixing Voltage-Referenced And Non-Voltage-Referenced I/O Standards - Altera Cyclone V Device Handbook

CV-52005
2014.01.10
The V
CCPD
to supply the pre-driver power to the output buffers increases the performance of the output pins.
Note: If the input signal is 3.0 V or 3.3 V, Altera recommends that you use a clamping diode on the I/O
pins.
Related Information
I/O Standards Voltage Levels in Cyclone V Devices

I/O Design Guidelines for Cyclone V Devices

There are several considerations that require your attention to ensure the success of your designs. Unless
noted otherwise, these design guidelines apply to all variants of this device family.

Mixing Voltage-Referenced and Non-Voltage-Referenced I/O Standards

Each I/O bank can simultaneously support multiple I/O standards. The following sections provide guidelines
for mixing non-voltage-referenced and voltage-referenced I/O standards in the devices.
Non-Voltage-Referenced I/O Standards
Each Cyclone V I/O bank has its own V
2.5, 3.0, or 3.3 V. An I/O bank can simultaneously support any number of input signals with different I/O
standard assignments if the I/O standards support the V
For output signals, a single I/O bank supports non-voltage-referenced output signals that drive at the same
voltage as V
non-voltage-referenced signals.
For example, an I/O bank with a 2.5 V V
3.0 V LVCMOS inputs only.
Related Information
I/O Standards Voltage Levels in Cyclone V Devices
Voltage-Referenced I/O Standards
To accommodate voltage-referenced I/O standards:
Each Cyclone V I/O bank contains a dedicated
Each bank can have only a single V
An I/O bank featuring single-ended or differential standards can support different voltage-referenced
standards if the V
For performance reasons, voltage-referenced input standards use their own V
This feature allows you to place voltage-referenced input signals in an I/O bank with a V
below. For example, you can place HSTL-15 input pins in an I/O bank with 2.5 V V
voltage-referenced input with R
the input standard. R
Voltage-referenced bidirectional and output signals must be the same as the V
For example, you can place only SSTL-2 output pins in an I/O bank with a 2.5 V V
I/O Features in Cyclone V Devices
Send Feedback
power pins must be connected to a 2.5 V, 3.0 V, or 3.3 V power supply. Using these power pins
. Because an I/O bank can only have one V
CCIO
and V are the same levels.
CCIO REF
OCT enabled requires the V
T
OCT cannot be supported for the HSTL-15 I/O standard when V
T
I/O Design Guidelines for Cyclone V Devices
on page 5-8
pins and supports only one V
CCIO
level of the I/O bank.
CCIO
CCIO
setting can support 2.5 V standard inputs and outputs, and
CCIO
on page 5-8
pin.
VREF
voltage level and a single voltage reference (V
CCIO
CCIO
of 1.2, 1.25, 1.35, 1.5, 1.8,
CCIO
value, it can only drive out the value for
level as the power source.
CCPD
CCIO
. However, the
CCIO
of the I/O bank to match the voltage of
CCIO
voltage of the I/O bank.
CCIO
.
CCIO
5-11
) level.
REF
of 2.5 V or
is 2.5 V.
Altera Corporation