quick.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

   

space.gif

   

space.gif

  ../images/main/bulllet_4dots_orange.gif Boolean Layer

Boolean layer is the lowest layer in concurrent layer, where boolean expression checking is done on variables. The result of boolean checking is either true or false. If the variables contain x or z, then the result is false.

   

space.gif

Boolean Expressions are allowed to include function calls, but certain semantic restrictions are imposed.

   

space.gif

  • Functions that appear in expressions cannot contain output or ref arguments (const ref are allowed).
  • Functions should be automatic (or preserve no state information) and have no side effects.
   

space.gif

Boolean layer can not use following Operan types.

   

space.gif

  • shortreal, real, and realtime
  • string
  • event
  • chandle
  • class
  • Associative arrays
  • Dynamic arrays
   

space.gif

All operators other then assignment, increment and decrement operators can be used in Boolean layer.

   

space.gif

  ../images/main/bullet_star_pink.gif Example : Boolean
   

space.gif


  1 module assertion_boolean();
  2 
  3 wire ce, en;
  4 wire [7:0] addr;
  5 
  6 // This code will not compile
  7 (en && ce && addr < 100);
  8 
  9 
 10 endmodule
You could download file assertion_boolean.sv here
   

space.gif

In the example above whole of (en && ce && addr < 100) is boolean layer, which contains boolean operation on variable , which evalutes to either TRUE or FALSE;

   

space.gif

   

space.gif

   

space.gif

   

space.gif

space2.gif

space2.gif

space2.gif

space2.gif

space2.gif

  

Copyright © 1998-2014

Deepak Kumar Tala - All rights reserved

Do you have any Comment? mail me at:deepak@asic-world.com