I/O Structure
MultiVolt I/O Interface
The MAX II architecture supports the MultiVolt I/O interface feature,
which allows MAX II devices in all packages to interface with systems of
different supply voltages. The devices have one set of VCCpins for
internal operation (VCCINT), and up to four sets for input buffers and I/O
output driver buffers (VCCIO), depending on the number of I/O banks
available in the devices where each set of VCC pins powers one I/O bank.
The EPM240 and EPM570 devices have two I/O banks respectively while
the EPM1270 and EPM2210 devices have four I/O banks respectively.
Connect VCCIOpins 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 (that is, when
VCCIOpins are connected to a 1.5-V power supply, the output levels are
compatible with 1.5-V systems). When VCCIOpins are connected to a
3.3-V power supply, the output high is 3.3 V and is compatible with 3.3-V
or 5.0-V systems. Table 2–7 summarizes MAX II MultiVolt I/O support.
Table 2–7. MAX II MultiVolt I/O Support Note (1)
Input Signal
Output Signal
VCCIO (V)
1.5 V
1.8 V
2.5 V
3.3 V
5.0 V
1.5 V
1.8 V
2.5 V
3.3 V
5.0 V
—
—
—
—
—
v
v
—
—
v
v
—
—
v
v
v
v
v
1.5
1.8
2.5
3.3
—
—
—
—
—
—
—
v
v
v
v (2)
v (3)
v (6)
v
v (3)
v (6)
v
v (6)
v (4)
v (5)
v
v (7)
Notes to Table 2–7:
(1) To drive inputs higher than VCCIO but less than 4.0 V including the overshoot, disable the PCI clamping diode.
However, to drive 5.0-V inputs to the device, enable the PCI clamping diode to prevent VI from rising above 4.0 V.
(2) When VCCIO = 1.8 V, a MAX II device can drive a 1.5-V device with 1.8-V tolerant inputs.
(3) When VCCIO = 2.5 V, a MAX II device can drive a 1.5-V or 1.8-V device with 2.5-V tolerant inputs.
(4) When VCCIO = 3.3 V and a 2.5-V input signal feeds an input pin, the VCCIO supply current will be slightly larger
than expected.
(5) MAX II devices can be 5.0-V tolerant with the use of an external resistor and the internal PCI clamp diode on the
EPM1270 and EPM2210 devices.
(6) When VCCIO = 3.3 V, a MAX II device can drive a 1.5-V, 1.8-V, or 2.5-V device with 3.3-V tolerant inputs.
(7) When VCCIO = 3.3 V, a MAX II device can drive a device with 5.0-V TTL inputs but not 5.0-V CMOS inputs. In the
case of 5.0-V CMOS, open-drain setting with internal PCI clamp diode (available only on EPM1270 and EPM2210
devices) and external resistor is required.
f
For information about output pin source and sink current guidelines,
refer to the AN 428: MAX II CPLD Design Guidelines.
2–40Core Version a.b.c variable
MAX II Device Handbook, Volume 1
Altera Corporation
March 2008
ALTERA [ ALTERA CORPORATION ]
