ep1agx50d Altera Corporation, ep1agx50d Datasheet - Page 124

• Manufacturer Part Number: ep1agx50d
• Description: Arria Gx Device Data Sheet
• Manufacturer: Altera Corporation

I/O Structure
2–116
Arria GX Device Handbook, Volume 1
f
Bus-hold circuitry also pulls undriven pins away from the input
threshold voltage where noise can cause unintended high-frequency
switching. You can select this feature individually for each I/O pin. The
bus-hold output drives no higher than V
signals. If the bus-hold feature is enabled, the programmable pull-up
option cannot be used. Disable the bus-hold feature when the I/O pin has
been configured for differential signals.
Bus-hold circuitry uses a resistor with a nominal resistance (RBH) of
approximately 7 kΩ to pull the signal level to the last-driven state. This
information is provided for each V
active only after configuration. When going into user mode, the bus-hold
circuit captures the value on the pin present at the end of configuration.
For the specific sustaining current driven through this resistor and
overdrive current used to identify the next-driven input level, refer to
the
Device Handbook.
Programmable Pull-Up Resistor
Each Arria GX device I/O pin provides an optional programmable
pull-up resistor during user mode. If you enable this feature for an I/O
pin, the pull-up resistor (typically 25 kΩ) holds the output to the V
level of the output pin’s bank.
Advanced I/O Standard Support
Arria GX device IOEs support the following I/O standards:
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
DC & Switching Characteristics
3.3-V LVTTL/LVCMOS
2.5-V LVTTL/LVCMOS
1.8-V LVTTL/LVCMOS
1.5-V LVCMOS
3.3-V PCI
3.3-V PCI-X mode 1
LVDS
LVPECL (on input and output clocks only)
Differential 1.5-V HSTL class I and II
Differential 1.8-V HSTL class I and II
Differential SSTL-18 class I and II
Differential SSTL-2 class I and II
1.2-V HSTL class I and II
1.5-V HSTL class I and II
1.8-V HSTL class I and II
SSTL-2 class I and II
SSTL-18 class I and II
CCIO
chapter in volume 1 of the Arria GX
voltage level. Bus-hold circuitry is
CCIO
to prevent overdriving
Altera Corporation
May 2008
CCIO