EP3C16F256I7 Altera, EP3C16F256I7 Datasheet - Page 166

• Manufacturer Part Number: EP3C16F256I7
• Description: Cyclone III
• Manufacturer: Altera

Cyclone III Device I/O Features
7–14
Cyclone III Device Handbook, Volume 1
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control the registers. This feature prevents the inadvertent activation of
another device's active-low input upon power up. If one register in an
IOE uses a preset or clear signal, then all registers in the IOE must use that
same signal if they require preset or clear. Additionally, a synchronous
reset signal is available for the IOE registers.
Refer to the Area and Timing Optimization chapter in volume 2 of the
Quartus II Handbook for more information about how to set the input and
output pin delay.
PCI-Clamp Diode
Cyclone III devices provide an optional PCI-clamp diode enabled input
and output for each I/O pin. The PCI-clamp diode is available for
3.3-V LVTTL, 3.3-V LVCMOS, 3.0-V LVTTL, 3.0-V LVCMOS, PCI, and
PCI-X I/O standards. If the input I/O standard is 3.3-V LVTTL, 3.3-V
LVCMOS, 3.0-V LVTTL, 3.3-V LVCMOS, PCI, or PCI-X, the PCI clamp
diod is enabled by default in Quartus II.
Refer to the Assignment Editor chapter in volume 2 of the Quartus II
Handbook for more information about how to set the PCI-Clamp diode
feature.
For more information about Cyclone III PCI-clamp diode support, refer
to AN 447: Interfacing Cyclone III Devices with 3.3/3.0/2.5-V
LVTTL/LVCMOS I/O Systems.
LVDS Transmitter Programmable Pre-Emphasis
The Cyclone III dedicated LVDS transmitter supports programmable
pre-emphasis. Programmable pre-emphasis is used to compensate the
frequency-dependent attenuation of the transmission line. It increases the
amplitude of the high-frequency components of the output signal, which
cancels out much of the high-frequency loss of the transmission line.
Programmable pre-emphasis supports on and off settings. The amount of
pre-emphasis needed depends on the amplification of the high-frequency
components along the transmission line. You need to adjust the setting to
suit your designs, as pre-emphasis decreases the amplitude of the low-
frequency component of the output signal as well.
For more information about Cyclone III high-speed differential interface
support, refer to High-Speed Differential Interfaces in the Cyclone III Devices
chapter of the Cyclone III Device Handbook.
Altera Corporation-Preliminary
March 2007