XC3S50 Datasheet, PDF (34/192 Pages) Xilinx, Inc – Revolutionary 90-nanometer process technology

R
a. CLKOUT_PHASE_SHIFT = NONE
CLKIN
CLKFB
Spartan-3 1.2V FPGA Family: Functional Description
b. CLKOUT_PHASE_SHIFT = FIXED
CLKIN
Shift Range over all P Values:
–255
CLKFB
0
P
256 ^{* TCLKIN}
+255
c. CLKOUT_PHASE_SHIFT = VARIABLE
CLKIN
Shift Range over all P Values:
–255
CLKFB before
Decrement
Shift Range over all N Values:
CLKFB after
Decrement
0
P
256
*
T_CLKIN
+255
–255
0
N
256
*
T_CLKIN
+255
DS099-2_11_031303
Notes:
1. P represents the integer value ranging from –255 to +255 to which the PHASE_SHIFT attribute is assigned.
2. N is an integer value ranging from –255 to +255 that represents the net phase shift effect from a series of increment and/or
decrement operations.
N = {Total number of increments} – {Total number of decrements}
A positive value for N indicates a net increment; a negative value indicates a net decrement.
Figure 17: Phase Shifter Waveforms
DS099-2 (v1.2) July 11, 2003
www.xilinx.com
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Advance Product Specification
1-800-255-7778