EP4CE55F23C8 Altera, EP4CE55F23C8 Datasheet - Page 87

• Manufacturer Part Number: EP4CE55F23C8
• Description: IC CYCLONE IV FPGA 55K 484FBGA
• Manufacturer: Altera
• Series: CYCLONE® IV Er

Specifications of EP4CE55F23C8

• Number Of Logic Elements/cells: 55856
• Number Of Labs/clbs: 3491
• Total Ram Bits: 2340000
• Number Of I /o: 324
• Voltage - Supply: 1.15 V ~ 1.25 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 484-FBGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Number Of Gates: -

Chapter 5: Clock Networks and PLLs in Cyclone IV Devices
Clock Feedback Modes
Zero Delay Buffer Mode
Deterministic Latency Compensation Mode
© December 2010 Altera Corporation
In zero delay buffer (ZDB) mode, the external clock output pin is phase-aligned with
the clock input pin for zero delay through the device. When using this mode, use the
same I/O standard on the input clock and output clocks to guarantee clock alignment
at the input and output pins.
Figure 5–15
in ZDB mode.
Figure 5–15. Phase Relationship Between PLL Clocks in ZDB Mode
The deterministic latency mode compensates for the delay of the multipurpose PLLs
through the clock network and serializer in Common Public Radio Interface (CPRI)
applications. In this mode, the PLL PFD feedback path compensates the latency
uncertainty in Tx dataout and Tx clkout paths relative to the reference clock.
External PLL Clock Output
shows an example waveform of the phase relationship of the PLL clocks
at the Register Clock Port
PLL Reference Clock
at the Output Pin
at the Input Pin
PLL Clock
Phase Aligned
Cyclone IV Device Handbook, Volume 1
5–25