An alternation network for use with a content addressable memory for implementing a divide and conquer algorithm is described. The comparator circuit generates a first level or second level of an activation signal in a manner dependent on the comparison of the control signal and the reference signal which are both fed to it on an input side. The XML document contains one or more network device operating system operations and associated data. Because the PPU implements coarse shading units and fine shading units, the PPU may tune the shading rate per-effect based on the frequency of variation across each pixel group.