Integrated circuit chips with multiplexed input/output pads and methods

Abstract

Integrated circuit chips with multiplexed input/output pads include means for expanding the functional and diagnostic capability of the circuit by increasing the effective number of input/output pads connected thereto so that more information can be provided to and from the chip. In particular, multiplexing means preferably provides the capability of accessing any one of a plurality of signal lines in the circuit from each input/output pad. This expanded capability is preferably achieved using one or more selection control signals which can be generated internally or externally to a chip containing the integrated circuit. An integrated circuit memory device, for example, preferably comprises a semiconductor substrate, a memory circuit in the substrate, a plurality of input/output pads and means, coupled to signal lines in the memory circuit, for multiplexing the plurality of input/output pads to the signal lines by electrically connecting respective ones of the signal lines to the input/output pads in response to a first select signal and electrically connecting respective others of the signal lines to the input/output pads in response to a second select signal. Because each pad on a chip can be connected to one or more signal lines, the memory circuit has a greater number of effective pads which means that a fewer number of pads on a small memory circuit chip can provide essentially the same input/output capability as a greater number of pads on a larger chip.