Semiconductor integrated circuit device which has first chip and second chip accessed via the first chip and test method thereof

Abstract

A semiconductor integrated circuit device includes a first chip including an internal circuit, and a second chip capable of being accessed only via the first chip, and a test processor circuit electrically connected internally via the first chip, for accessing the second chip from an external terminal and testing the second chip, and a test circuit where an input/output buffer is installed for signals for accessing the second chip within the test processor circuit, and a bypass line installed for transferring signals from the first chip to the second chip and avoiding the input/output buffer within the test processor circuit, and a switch which switches between signal transfer path via the input/output buffer, and a signal transfer path via the bypass line.