Abstract: A cell for inclusion in a cell library used in designing integrated circuits. The cell includes a signal processing circuit and a buffer circuit for buffering a signal external to an integrated circuit in which the cell is to be included. The cell also includes layout information for specifying a layout of an interconnecting trace between the signal processing circuit and the buffer circuit. The invention is also directed to a method for performing layout and routing during design of an integrated circuit, in which cells are obtained from a cell library, the obtained cells are laid out on an integrated circuit die, interconnections are routed between the cells.

Abstract: A multi-sided, integrated circuit die includes a plurality of read only memory (ROM) circuits, positioned only at the corners of the die, to simplify qualification testing of new package designs. During qualification testing, electrical and environmental stresses are applied to the package and die combination. The package and die are electronically evaluated at predetermined intervals to determine whether a failure has occurred during testing. When a failure occurs during testing, the package and die are diagnosed to isolate and determine the cause or source of the failure. Package design parameters are adjusted accordingly to reduce or eliminate the occurrence of the failures. An optional 12-bit counter is fabricated onto the die for each ROM circuit to exercise the ROM during qualification testing. An optional process monitor is also fabricated onto the die for each ROM circuit to determine the strength of the fabrication process and the resulting quality of circuit elements produced therefrom.