XC3SD1800A-4CS484I Xilinx Inc, XC3SD1800A-4CS484I Datasheet - Page 47

• Manufacturer Part Number: XC3SD1800A-4CS484I
• Description: FPGA Spartan®-3A Family 1.8M Gates 37440 Cells 667MHz 90nm Technology 1.2V 484-Pin LCSBGA
• Manufacturer: Xilinx Inc

Specifications of XC3SD1800A-4CS484I

• Package: 484LCSBGA
• Family Name: Spartan®-3A
• Device Logic Units: 37440
• Device System Gates: 1800000
• Maximum Internal Frequency: 667 MHz
• Typical Operating Supply Voltage: 1.2 V
• Maximum Number Of User I/os: 309
• Ram Bits: 1548288

Table 39: Switching Characteristics for the DFS
DS610 (v3.0) October 4, 2010
Product Specification
CLKOUT_DUTY_CYCLE_
FX
Notes:
1.
2.
3.
4.
5.
6.
Output Frequency Ranges
CLKOUT_FREQ_FX
Output Clock Jitter
CLKOUT_PER_JITT_FX
Duty Cycle
Phase Alignment
CLKOUT_PHASE_FX
CLKOUT_PHASE_FX180 Phase offset between the DFS CLKFX180 output and
Lock Time
LOCK_FX
The numbers in this table are based on the operating conditions set forth in
DFS performance requires the additional logic automatically added by ISE 9.1i and later software revisions.
For optimal jitter tolerance and faster lock time, use the CLKIN_PERIOD attribute.
Maximum output jitter is characterized within a reasonable noise environment (150 ps input period jitter, 40 SSOs and 25% CLB switching)
on an FPGA. Output jitter strongly depends on the environment, including the number of SSOs, the output drive strength, CLB utilization,
CLB switching activities, switching frequency, power supply and PCB design. The actual maximum output jitter depends on the system
application.
The CLKFX and CLKFX180 outputs always have an approximate 50% duty cycle.
Some duty-cycle and alignment specifications include a percentage of the CLKFX output period. For example, the data sheet specifies a
maximum CLKFX jitter of “±[1% of CLKFX period + 200]”. Assume the CLKFX output frequency is 100 MHz. The equivalent CLKFX period
is 10 ns and 1% of 10 ns is 0.1 ns or 100 ps. According to the data sheet, the maximum jitter is ±[100 ps + 200 ps] = ±300 ps.
Symbol
(2)(3)
(5)(6)
(6)
(2)
(3)(4)
Frequency for the CLKFX and CLKFX180 outputs
Period jitter at the CLKFX and
CLKFX180 outputs.
Duty cycle precision for the CLKFX and CLKFX180
outputs, including the BUFGMUX and clock tree
duty-cycle distortion
Phase offset between the DFS CLKFX output and the
DLL CLK0 output when both the DFS and DLL are used
the DLL CLK0 output when both the DFS and DLL are
used
The time from deassertion at the
DCM’s Reset input to the rising
transition at its LOCKED output. The
DFS asserts LOCKED when the
CLKFX and CLKFX180 signals are
valid. If using both the DLL and the
DFS, use the longer locking time.
Description
Spartan-3A DSP FPGA Family: DC and Switching Characteristics
www.xilinx.com
5 MHz < F
≤
> 20 MHz
< 15 MHz
F
15 MHz
CLKIN
CLKIN
CLKIN
20 MHz
Table 7
CLKIN
>
and
Device
All
All
All
All
All
All
Table
Use the Spartan-3A Jitter Calculator:
www.xilinx.com/support/documentation/
±[1% of
CLKFX
period
+ 100]
38.
Min
Typ
5
–
–
–
–
–
data_sheets/s3a_jitter_calc.zip
-5
±[1% of
±[1% of
±[1% of
CLKFX
CLKFX
CLKFX
period
+ 200]
period
+ 350]
period
+ 200]
±200
Speed Grade
Max
Max
350
450
5
±[1% of
CLKFX
period
+ 100]
Min
Typ
5
–
–
–
–
–
-4
±[1% of
±[1% of
±[1% of
CLKFX
CLKFX
CLKFX
period
+ 200]
period
+ 350]
period
+ 200]
±200
Max
Max
311
450
5
Units
MHz
ms
ps
ps
ps
ps
ps
µs
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