XC5VLX50T-1FFG665C Xilinx Inc, XC5VLX50T-1FFG665C Datasheet - Page 103

• Manufacturer Part Number: XC5VLX50T-1FFG665C
• Description: FPGA, VIRTEX-5 LXT, 50K, 665FCBGA
• Manufacturer: Xilinx Inc
• Series: Virtex™-5 LXTr

Specifications of XC5VLX50T-1FFG665C

• No. Of Logic Blocks: 7200
• Family Type: Virtex-5
• No. Of Speed Grades: 1
• Total Ram Bits: 2211840
• No. Of I/o's: 360
• Clock Management: DCM, PLL
• I/o Supply Voltage: 3.3V
• Operating Frequency Max: 550MHz
• Number Of Logic Elements/cells: 46080
• Number Of Labs/clbs: 3600
• Number Of I /o: 360
• Voltage - Supply: 0.95 V ~ 1.05 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 665-BBGA, FCBGA
• Core Supply Voltage Range: 1V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: HW-V5-ML561-UNI-G - EVALUATION PLATFORM VIRTEX-5HW-V5-ML550-UNI-G - EVALUATION PLATFORM VIRTEX-5HW-V5-ML521-UNI-G - EVALUATION PLATFORM VIRTEX-5HW-V5GBE-DK-UNI-G - KIT DEV V5 LXT GIGABIT ETHERNET122-1508 - EVALUATION PLATFORM VIRTEX-5
• Number Of Gates: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 122-1565

Detailed VCO and Output Counter Waveforms
Virtex-5 FPGA User Guide
UG190 (v5.3) May 17, 2010
Clock Shifting
The PLL output clocks can be shifted by inserting delay by selecting one of the eight phases
in either the reference or the feedback path.
edge at the output of the PLL without any shifting versus the two cases (delay inserted in
the feedback path and delay inserted in the reference path).
X-Ref Target - Figure 3-7
Figure 3-8
VCO phase is shown with the appropriate start-up sequence. The phase relationship and
start-up sequence are guaranteed to insure the correct phase is maintained. This means the
rising edge of the 0° phase will happen before the rising edge of the 45° phase. The O0
counter is programmed to do a simple divide by two with the 0° phase tap as the reference
clock. The O1 counter is programmed to do a simple divide by two but uses the 180° phase
tap from the VCO. Phase shifts greater than one VCO period are possible. This counter
setting could be used to generate a clock for a DDR interface where the reference clock is
edge aligned to the data transition. The O2 counter is programmed to do a divide by three.
The O3 output has the same programming as the O2 output except the phase is set for a
one cycle delay.
If the PLL is configured to provide a certain phase relationship and the input frequency is
changed, then this phase relationship is also changed since the VCO frequency changes
and therefore the absolute shift in picoseconds will change. This aspect must be considered
when designing with the PLL. When an important aspect of the design is to maintain a
certain phase relationship amongst various clock outputs, (e.g., CLK and CLK90) then this
relationship will be maintained regardless of the input frequency.
added delay in
added delay in
reference path
feedback path
shows the eight VCO phase outputs and four different counter outputs. Each
original
clock
Figure 3-7: Basic Output Clock Shifting
www.xilinx.com
Detailed VCO and Output Counter Waveforms
Figure 3-7
shows the effect on a clock signal
dT
feedback
dT
reference
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