XC4VFX40-12FFG1152C Xilinx Inc, XC4VFX40-12FFG1152C Datasheet - Page 30

• Manufacturer Part Number: XC4VFX40-12FFG1152C
• Description: IC FPGA VIRTEX-4 FX 40K 1152FBGA
• Manufacturer: Xilinx Inc
• Series: Virtex™-4r

Specifications of XC4VFX40-12FFG1152C

• Number Of Logic Elements/cells: 41904
• Number Of Labs/clbs: 4656
• Total Ram Bits: 2654208
• Number Of I /o: 448
• Voltage - Supply: 1.14 V ~ 1.26 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 1152-BBGA, FCBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Gates: -

Chapter 1: Clock Resources
30
The timing diagram in
BUFGCTRL primitives. Exact timing numbers are best found using the speed specification.
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Other capabilities of BUFGCTRL are:
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IGNORE0
IGNORE1
Before time event 1, output O uses input I0.
At time T
deasserted Low. At about the same time, both CE1 and S1 are asserted High.
At time T
to Low transition of I0 (event 2) followed by a High to Low transition of I1.
At time event 4, IGNORE1 is asserted.
At time event 5, CE0 and S0 are asserted High while CE1 and S1 are deasserted Low.
At T
requiring a High to Low transition of I1.
Pre-selection of the I0 and I1 inputs are made after configuration but before device
operation.
The initial output after configuration can be selected as either High or Low.
Clock selection using CE0 and CE1 only (S0 and S1 tied High) can change the clock
selection without waiting for a High to Low transition on the previously selected
clock.
CE0
CE1
S0
S1
I0
I1
O
BCCKO_O
BCCCK_CE
BCCKO_O
, after time event 6, output O has switched from I1 to I0 without
, after time event 3, output O uses input I1. This occurs after a High
Figure 1-2
Figure 1-2: BUFGCTRL Timing Diagram
, before the rising edge at time event 1, both CE0 and S0 are
at I0
www.xilinx.com
T
BCCKO_O
1
illustrates various clock switching conditions using the
T
BCCCK_CE
2
T
BCCKO_O
3
Begin I1
4
UG070 (v2.6) December 1, 2008
Virtex-4 FPGA User Guide
Begin I0
5
T
BCCKO_O
6
UG070_1_02_072907
R