EPF10K30E Datasheet, PDF (42/100 Pages) Altera Corporation – Embedded Programmable Logic Device

FLEX 10KE Embedded Programmable Logic Devices Data Sheet
PCI Pull-Up Clamping Diode Option
FLEX 10KE devices have a pull-up clamping diode on every I/O,
dedicated input, and dedicated clock pin. PCI clamping diodes clamp the
signal to the V_CCIO value and are required for 3.3-V PCI compliance.
Clamping diodes can also be used to limit overshoot in other systems.
Clamping diodes are controlled on a pin-by-pin basis. When V_CCIO is
3.3 V, a pin that has the clamping diode option turned on can be driven by
a 2.5-V or 3.3-V signal, but not a 5.0-V signal. When V_CCIO is 2.5 V, a pin
that has the clamping diode option turned on can be driven by a 2.5-V
signal, but not a 3.3-V or 5.0-V signal. Additionally, a clamping diode can
be activated for a subset of pins, which would allow a device to bridge
between a 3.3-V PCI bus and a 5.0-V device.
Slew-Rate Control
The output buffer in each IOE has an adjustable output slew rate that can
be configured for low-noise or high-speed performance. A slower slew
rate reduces system noise and adds a maximum delay of 4.3 ns. The fast
slew rate should be used for speed-critical outputs in systems that are
adequately protected against noise. Designers can specify the slew rate
pin-by-pin or assign a default slew rate to all pins on a device-wide basis.
The slow slew rate setting affects the falling edge of the output.
Open-Drain Output Option
FLEX 10KE devices provide an optional open-drain output (electrically
equivalent to open-collector output) for each I/O pin. This open-drain
output enables the device to provide system-level control signals (e.g.,
interrupt and write enable signals) that can be asserted by any of several
devices. It can also provide an additional wired-OR plane.
MultiVolt I/O Interface
The FLEX 10KE device architecture supports the MultiVolt I/O interface
feature, which allows FLEX 10KE devices in all packages to interface with
systems of differing supply voltages. These devices have one set of V_CC
pins for internal operation and input buffers (VCCINT), and another set for
I/O output drivers (VCCIO).
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