Patent ID: 7802154

Claim:
A method of generating a high-frequency command signal and a high-frequency address signal, comprising: grouping a command signal into a command signal group; grouping an address signal into an address signal group, each of said command signal and said address signal corresponding to L cycles of a clock signal output from an automatic test equipment (ATE) used to test a semiconductor memory device where L is a natural number greater than 1; extracting a valid command signal and a valid address signal, each of which are not in an idle state, from each of said command signal groups and each of said address signal groups; compressing the valid command signal and the valid address signal into signals having a length corresponding to 1/M of a cycle of the clock signal where M is a natural number larger than 1; generating a position designating signal indicating the positions of the valid command signal and the valid address signal in each command signal group and each address signal group, respectively; and generating the high-frequency command signal from the compressed valid command signal and the high-frequency address signal from the compressed valid address signal using the position designating signal.