Patent ID: 6563727
Filing Date: 2003-05-13
Classification: G11C

Abstract:
A method for reducing the coupling noise in a Content Addressable Memory (CAM), said CAM having a first bitline pair and a second bitline pair, each aligned along a first axis; a first half memory cell connected to said first bitline pair and a second half memory cell to said second bitline pair; having a first match line and a first word line aligned along a second axis, said first match line and said first word line connecting said first half and said second half memory cells defining a first row in a first column; a second row adjacent said first row, said second row comprising a third half cell and a fourth half cell, said third and fourth half cells connecting said first and second bitline pairs and a second word line and a second match line, said method comprising:(a) arranging said first half memory cell in a first orientation and said second half memory cell in a second orientation, wherein said second orientation is a mirror image of said first orientation; (b) twisting said first and second bitline pairs between said first row and said second row; (c) arranging said third half cell in a third orientation, said third orientation being rotated 180 degrees with respect to said first orientation; and (d) arranging said fourth half cell in a fourth orientation, said fourth orientation being rotated 180 degrees with respect to said second orientation.