Patent ID: 7107458

Claim:
A semiconductor integrated circuit comprising: a first operating unit which has a first nonvolatile memory to which a first program is stored, and a control unit generating a first key code in accordance with the first program, an encryption unit which has a first register and which encrypts communication data in accordance with the first key code stored in the first register; an interface unit which communicates in accordance with a predetermined protocol; and an internal bus which is coupled to the first operating unit, the encryption unit, and the interface unit, wherein the first nonvolatile memory, the control unit, the encryption unit, the interface unit, and the internal bus coupled to the first nonvolatile memory and the control unit are formed on a single semiconductor chip, wherein the first operation unit performs a first operation in which the control unit reads out the first program from the first nonvolatile memory, a second operation in which the control unit generates the key code in accordance with the first program, and a third operation in which the control unit sets the first key code to the first register via the internal bus, on the single semiconductor chip.