Patent ID: 6507937
Filing Date: 2003-01-14
Classification: G06F

Abstract:
A method of control cell placement comprising the steps of:(a) receiving as input a datapath description including an initial set of coordinates for a plurality of control cells; (b) ordering the plurality of control cells in a sequence according to distance between each of the plurality of control cells and at least one fixed control cell in the plurality of control cells wherein n is the number of control cells in the datapath description; (c) iteratively calculating globally optimum coordinates for the each of the plurality of control cells in the sequence according to a global maximum of a control cell placement function; and (d) generating as output the calculated globally optimum coordinates (Xi,Yi) for the each of the plurality of control cells wherein the global maximum of the control cell placement function for calculating the globally optimum coordinates (Xi,Yi) for the each of the plurality of control cells is given substantially by the following equations: Xi&it;&Sum;j&Element;Ai&it;Wij&it;Xj&it;&Sum;p&Element;Pi&it;&Sum;s&Element;Pj&it;Wijp&it;â€ƒ&it;s&af;(Xip&it;â€ƒ&it;Xjs)&Sum;j&Element;Ai&it;WijYi&it;&Sum;j&Element;Ai&it;Wij&it;Yj&it;&Sum;p&Element;Pi&it;&Sum;s&Element;Pj&it;Wijp&it;â€ƒ&it;s&af;(Yip&it;â€ƒ&it;Yjs)&Sum;j&Element;Ai&it;Wijwherein Ai is the set of nodes adjacent to node i, Pi and Pj are the sets of internal pins for nodes i and j, respectively, and Wifpa is a weight of edge (i, j) connecting internal pin p of node 1 and pin s of node j.