Semiconductor memory devices including mode registers and systems including the same

摘要

Semiconductor memory devices are provided. The semiconductor memory device includes a command decoder, a code converter and a code outputting unit. The command decoder is configured to receive a plurality of command signals from an external source, decode the plurality of command signals and generate a mode register reading signal responsive to the decoded plurality of command signals. The code converter is configured to receive mode setting codes generated based on the decoded plurality of command signals and convert the mode setting codes to serial mode setting codes. The code outputting unit is configured to receive the serial mode setting codes and output the serial mode setting codes to the external source responsive to the mode register reading signal. Systems including the semiconductor memory devices are also provided.