EP3C16F484I7N Altera, EP3C16F484I7N Datasheet - Page 81

• Manufacturer Part Number: EP3C16F484I7N
• Description: Cyclone III
• Manufacturer: Altera

Specifications of EP3C16F484I7N

• Family Name: Cyclone III
• Number Of Logic Blocks/elements: 15408
• # I/os (max): 346
• Frequency (max): 437.5MHz
• Process Technology: 65nm
• Operating Supply Voltage (typ): 1.2V
• Logic Cells: 15408
• Ram Bits: 516096
• Operating Supply Voltage (min): 1.15V
• Operating Supply Voltage (max): 1.25V
• Operating Temp Range: -40C to 100C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 484
• Package Type: FBGA
• Lead Free Status / Rohs Status: Compliant

Chapter 5: Clock Networks and PLLs in the Cyclone III Device Family
Hardware Features
PLL Control Signals
© December 2009
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Altera Corporation
You can use the following three signals to observe and control the PLL operation and
resynchronization.
pfdena
Use the pfdena signal to maintain the last locked frequency so that your system has
time to store its current settings before shutting down. The pfdena signal controls the
PFD output with a programmable gate. If you disable the PFD, the VCO operates at
its last set value of control voltage and frequency with some long-term drift to a lower
frequency.
areset
The areset signal is the reset or resynchronization input for each PLL. The device
input pins or internal logic can drive these input signals. When driven high, the PLL
counters reset, clearing the PLL output and placing the PLL out of lock. The VCO is
then set back to its nominal setting. When driven low again, the PLL resynchronizes
to its input as it re-locks.
You must include the areset signal in your designs if one of the following
conditions is true:
■
■
If the input clock to the PLL is toggling or unstable upon power up, assert the areset
signal after the input clock is stable and within specifications.
locked
The locked output indicates that the PLL has locked onto the reference clock and the
PLL clock outputs are operating at the desired phase and frequency set in the
Quartus II MegaWizard
Altera recommends that you use the areset and locked signals in your designs to
control and observe the status of your PLL.
This implementation is illustrated in
Figure 5–13. Locked Signal Implementation
PLL reconfiguration or clock switchover enabled in your design
Phase relationships between the PLL input clock and output clocks must be
maintained after a loss-of-lock condition
™
PLL
Plug-in Manager.
locked
Figure
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CC
5–13.
D
OFF
Q
areset
Cyclone III Device Handbook, Volume 1
locked
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