prev FPGA 2002 next
Checkerboard, Commutative Design Framework
Switch Block Design Problem

Given:
  • length 4 wires + checkerboard = 8x8 grid
Consider all possible two-turn paths:
  • 8 choose 2 = 28 pairs of paths to same output
  • 7 possible output rows
  • 6 types of two-point turns
  • 6 x 7 x 28 = 1176 pairs of canonical expressions
  • note: without checkerboard, only 6 x 3 x 6 = 108 pairs
        more pairs => greater diversity potential
Find:
  • mapping functions f, g for two switch blocks
Goal:
  • choose f, g for maximum diversity, such that each pair
    of canonical expressions maps to a different track