| 摘要 |
PURPOSE:To protect a stored data from easy readout by ciphering a data to be inputted to a register. CONSTITUTION:A transmission gate 6 is turned on, a transmission gate 7 is turned off, the data of 'H' or 'L' level is inputted to a circuit input/output terminal 1 and the data of 'H' or 'L' level (this is the cipher, whether it is 'H' or 'L' level is stored) is inputted to a register 3. An EXOR 4 outputs the exclusive OR of the data inputted to the circuit input/output terminal 1 and the register 3, and the output from the EXOR 4 is stored in a memory 2, where the 'L' data is stored. Thus, the stored data is protected from easy readout. |
