XC2VP7-5FFG896I Xilinx Inc, XC2VP7-5FFG896I Datasheet - Page 62
Manufacturer Part Number
IC FPGA VIRTEX-II PRO 896-FBGA
Specifications of XC2VP7-5FFG896I
Number Of Logic Elements/cells
Number Of Labs/clbs
Total Ram Bits
Number Of I /o
Voltage - Supply
1.425 V ~ 1.575 V
-40°C ~ 100°C
Package / Case
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Number Of Gates
If the presently selected clock is Low while S changes, or if
it goes Low after S has changed, the output is kept Low until
the other ("to-be-selected") clock has made a transition
from High to Low. At that instant, the new clock starts driv-
ing the output.
The two clock inputs can be asynchronous with regard to
each other, and the S input can change at any time, except
for a short setup time prior to the rising edge of the presently
selected clock (I0 or I1). Violating this setup time require-
ment can result in an undefined runt pulse output.
All Virtex-II Pro devices have 16 global clock multiplexer
In addition to global clocks, there are local clock resources
in the Virtex-II Pro devices. There are more than 72 local
clocks in the Virtex-II Pro family. These resources can be
used for many different applications, including but not lim-
ited to memory interfaces. For example, even using only the
DS083 (v4.7) November 5, 2007
Figure 61: Clock Multiplexer Waveform Diagram
The current clock is CLK0.
S is activated High.
If CLK0 is currently High, the multiplexer waits for CLK0
to go Low.
Once CLK0 is Low, the multiplexer output stays Low
until CLK1 transitions High to Low.
When CLK1 transitions from High to Low, the output
switches to CLK1.
No glitches or short pulses can appear on the output.
Figure 60: Virtex-II Pro BUFGMUX Function
shows a switchover from I0 to I1.
Wait for Low
Virtex-II Pro and Virtex-II Pro X Platform FPGAs: Functional Description
left and right I/O banks, Virtex-II Pro FPGAs can support up
to 50 local clocks for DDR SDRAM. These interfaces can
operate beyond 200 MHz on Virtex-II Pro devices.
Digital Clock Manager (DCM)
The Virtex-II Pro DCM offers a wide range of powerful clock
The DCM utilizes fully digital delay lines allowing robust
high-precision control of clock phase and frequency. It also
utilizes fully digital feedback systems, operating dynamically
to compensate for temperature and voltage variations dur-
Up to four of the nine DCM clock outputs can drive inputs to
global clock buffers or global clock multiplexer buffers simul-
taneously drive general routing resources, including routes
to output buffers.
The DCM can be configured to delay the completion of the
Virtex-II Pro configuration process until after the DCM has
achieved lock. This guarantees that the chip does not begin
operating until after the system clocks generated by the
DCM have stabilized.
Clock De-skew: The DCM generates new system
clocks (either internally or externally to the FPGA),
which are phase-aligned to the input clock, thus
eliminating clock distribution delays.
Frequency Synthesis: The DCM generates a wide
range of output clock frequencies, performing very
flexible clock multiplication and division.
Phase Shifting: The DCM provides both coarse phase
shifting and fine-grained phase shifting with dynamic
phase shift control.
Figure 62: Digital Clock Manager
62). All DCM clock outputs can simul-
Module 2 of 4