| 摘要 |
PROBLEM TO BE SOLVED: To provide a byte replacement computing element which can reduce its exclusive area and power consumption when it's transformed into an integrated circuit by decreasing the numbers of transistors and wirings. SOLUTION: The upper or lower halves of two 64-bit numbers A and B which are inputted via the 1st-stage selector groups S11 to S18 are selected and alternately rearranged with each other every 8 bits (1 byte). The outputs of groups S11 to S18 are inputted to the 2nd-stage selector groups S21 to S24 to decide whether center 2 bytes of each of sets divided every 4 bytes should be replaced in each byte. Furthermore, the outputs of groups S21 to S24 are inputted to the 3rd-stage selector groups S31 to S34 or the outputs of groups S11 to S18 are inputted to the groups S31 to S34 for the bytes lacking the groups S21 to S24 respectively. Then it's decided whether center 4 bytes of each of sets divided every 8 bytes should be replaced every 2 bytes. |
