Integrated circuit formed from a semiconductor body having a rectangular grid pattern formed on the body. The grid pattern is defined by lines extending at right angles to each other along X and Y axes. A plurality of basic cells are provided which have a plurality of active elements therein. Each of the basic cells is selected from a limited number of basic cells of different designs. Each of the basic cells is disposed within a rectangular area no greater than a predetermined size and overlying a plurality of grid lines on both the X and Y axes so that each basic cell overlies a plurlity of intersections of the grid lines which define predetermined grid points. Each basic cell includes a power bus, a ground bus, input leads and an output having a predetermined arrangement with respect to certain grid points. The power bus and ground bus and the input leads and output of each basic cell are connected to the basic cell. Leads are provided for connecting the basic cells to form larger integrated circuit units which are called unit cells. The unit cells are connected to form still larger integrated circuits called a function block (FB).