Altera Corporation 27
FLEX 6000 Programmable Logic Device Family Data Sheet
MultiVolt I/O Interface
The FLEX 6000 device architecture supports the MultiVolt I/O interface
feature, which allows FLEX 6000 devices to interface with systems of
differing supply voltages. The EPF6016 device can be set for 3.3-V or 5.0-V
I/O pin operation. This device has one set of V
CC
pins for internal
operation and input buffers (VCCINT), and another set for output drivers
(VCCIO).
The VCCINT pins on 5.0-V FLEX 6000 devices must always be connected
to a 5.0-V power supply. With a 5.0-V V
CCINT
level, input voltages are at
TTL levels and are therefore compatible with 3.3-V and 5.0-V inputs.
The VCCIO pins on 5.0-V FLEX 6000 devices can be connected to either a
3.3-V or 5.0-V power supply, depending on the output requirements.
When the VCCIO pins are connected to a 5.0-V power supply, the output
levels are compatible with 5.0-V systems. When the VCCIO pins are
connected to a 3.3-V power supply, the output high is 3.3 V and is
therefore compatible with 3.3-V or 5.0-V systems. Devices operating with
V
CCIO
levels lower than 4.75 V incur a nominally greater timing delay of
t
OD2
instead of t
OD1
.
On 3.3-V FLEX 6000 devices, the VCCINT pins must be connected to a
3.3-V power supply. Additionally, 3.3-V FLEX 6000A devices can interface
with 2.5-V, 3.3-V, or 5.0-V systems when the VCCIO pins are tied to 2.5 V.
The output can drive 2.5-V systems, and the inputs can be driven by 2.5-
V, 3.3-V, or 5.0-V systems. When the VCCIO pins are tied to 3.3 V, the
output can drive 3.3-V or 5.0-V systems. MultiVolt I/Os are not supported
on 100-pin TQFP or 100-pin FineLine BGA packages.
Table 7 describes FLEX 6000 MultiVolt I/O support.
Note:
(1) When V
CCIO
= 3.3 V, a FLEX 6000 device can drive a 2.5-V device that has 3.3-V
tolerant inputs.
Table 7. FLEX 6000 MultiVolt I/O Support
V
CCINT
(V)
V
CCIO
(V)
Input Signal (V) Output Signal (V)
2.53.35.02.53.35.0
3.3 2.5
vvvv
3.3 3.3
vvv
v
(1)
vv
5.0 3.3
vv vv
5.0 5.0
vv v
