Device Architecture
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Pr el iminar y v1 .7
Special Function Pins
NC
No Connect
This pin is not connected to circuitry within the device. These pins can be driven to any voltage or
can be left floating with no effect on the operation of the device.
DC
Don't Connect
This pin should not be connected to any signals on the PCB. These pins should be left unconnected.
NCAP
Negative Capacitor
Negative Capacitor is where the negative terminal of the charge pump capacitor is connected. A
capacitor, with a 2.2 F recommended value, is required to connect between PCAP and NCAP.
PCAP
Positive Capacitor
Positive Capacitor is where the positive terminal of the charge pump capacitor is connected. A
capacitor, with a 2.2 F recommended value, is required to connect between PCAP and NCAP.
PUB
Push Button
Push button is the connection for the external momentary switch used to turn on the 1.5 V voltage
regulator and can be floating if not used.
PTBASE
Pass Transistor Base
Pass Transistor Base is the control signal of the voltage regulator. This pin should be connected to
the base of the external pass transistor used with the 1.5 V internal voltage regulator and can be
floating if not used.
PTEM
Pass Transistor Emitter
Pass Transistor Emitter is the feedback input of the voltage regulator.
This pin should be connected to the emitter of the external pass transistor used with the 1.5 V
internal voltage regulator and can be floating if not used.
XTAL1
Crystal Oscillator Circuit Input
Input to crystal oscillator circuit. Pin for connecting external crystal, ceramic resonator, RC network,
or external clock input. When using an external crystal or ceramic oscillator, external capacitors are
also recommended (Please refer to the crystal oscillator manufacturer for proper capacitor value).
If using external RC network or clock input, XTAL1 should be used and XTAL2 left unconnected.
XTAL2
Crystal Oscillator Circuit Input
Input to crystal oscillator circuit. Pin for connecting external crystal, ceramic resonator, RC network,
or external clock input. When using an external crystal or ceramic oscillator, external capacitors are
also recommended (Please refer to the crystal oscillator manufacturer for proper capacitor value).
If using external RC network or clock input, XTAL1 should be used and XTAL2 left unconnected.
Software Tools and Programming
Overview of Tools Flow
The Fusion family of FPGAs is fully supported by both Actel Libero IDE and Designer FPGA
development software. Actel Libero IDE is an integrated design manager that seamlessly integrates
design tools while guiding the user through the design flow, managing all design and log files, and
passing necessary design data among tools. Additionally, Libero IDE allows users to integrate both
schematic and HDL synthesis into a single flow and verify the entire design in a single environment
from Synplicity, ViewDraw AE from Mentor Graphics, ModelSim HDL Simulator from Mentor
Graphics, WaveFormer Lite AE from SynaptiCAD, PALACE AE Physical Synthesis from Magma
Design Automation, and Designer software from Actel.