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| XILINX APPLICATIONS NOTE XAPP028V-V1.00                   BN-5-16-94  |
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README file for the XC3000A phase/frequency detector macro:
===========================================================

Note: A more detailed description of this application can be found in
Section 8 of the Xilinx Data Book.

Files included in XAPP028V.ZIP:
-------------------------------
  
  README          This readme file
  SCH\APF_DET.1   Top-level test schematic
  SCH\FREQ_DET.1  Phase/frequency-detector macro
  SYM\            Symbol for the phase/frequency detector
  WIR\            Wire files for the above designs

  XNF\            XNF files
  APF_DET.LCA     Routed design file

This XAPP file contains a macro for the phase/frequency detector described in 
XAPP022. For best performance, the macro should be placed adjacent to the IOBs 
it uses. The macro provided contains location constraints that force it to the
top left corner. These can be changed as desired.

Software Versions used:

  DS390 Version 4.1.3a Viewlogic and Interface

