Patent ID: 8269521

Claim:
A chip select apparatus, for controlling n stacked chips identical to each other, the chip select apparatus comprising: n identification (ID) code generators, having an ID code generator disposed in an i th chip of the chips, wherein n is an integer, and i is an integer between 1 and n, wherein a first ID code generator of the ID code generators receives a first seed code, and generates a first ID code and a second seed code according to the first seed code, and an i th ID code generator is electrically connected to an (i−1) th ID code generator to receive an seed code, and generates an i th ID code and an (i+1) th seed code according to the i th seed code, wherein the first ID code to an n th ID code are different to each other; and n activation logic units, each having an activation code, an i th activation logic unit in the activation logic units being disposed in the i th chip of the chips, and the i th activation logic unit being electrically connected to the i th ID code generator for receiving the ID code, wherein the activation logic unit activates the chip when the ID code received by the i th activation logic unit is complied with the activation code, wherein the activation codes built in the activation logic units respectively disposed in the n stacked chips are the same code, wherein each of the first to the n th ID codes changes as the first seed code changes, such that one of the n stacked chips is selected and activated in response to the first seed code and the same activation codes.