Semiconductor devices configured to test connectivity of micro bumps including one or more micro bumps and a boundary scan test block for testing connectivity of the micro bumps by scanning data input to the micro bumps and outputting the scanned data. The semiconductor device may include a first chip including solder balls and at least one or more switches electrically coupled with the respective solder balls, and a second chip stacked on top of the first chip and electrically coupled with the switches in direct access mode, including micro bumps that input/output signals transmitted from/to the solder balls.