Patent ID: 8767502

Claim:
A semiconductor device comprising: an access control circuit generating an internal command based on a verification result signal and an external command, the external command including a first bit and a plurality of second bits supplied from outside, the access control circuit including a verification circuit verifying the second bits of the external command to generate the verification result signal; and a first circuit operating based on the internal command supplied from the access control circuit, wherein the external command indicates at least one of a first command that enables the access control circuit to access the first circuit and a second command that enables the access control circuit not to access the first circuit or enables the access control circuit to maintain a current state of the first circuit, the access control circuit, when the verification result signal indicates a first logic level, generates the internal command based on the external command, and the access control circuit, when the verification result signal indicates a second logic level, generates the internal command that corresponds to the second command even if the external command indicates the first command.