| 摘要 |
PROBLEM TO BE SOLVED: To provide the high-speed code conversion circuit from BIN (binary number) to BCD(binary coded decimal number) of small current consumption. SOLUTION: This circuit is provided with the first shift registers 1 (11 -1n ) of (n) stage constitution for storing BCD data by 4 bits each and the second shift registers 2 (21 -2m ) of (m) stage constitution for storing the BIN data of a conversion object by 4 bits each. The output of a D type flip-flop (D-F/F) 5 for holding the output of the first shift registers 1 and an intermediate result is switched by a selector 3, the output of the second shift registers 2 is selected by the selector 4 and they are respectively supplied to an arithmetic circuit 6. The arithmetic circuit 6 executes the processing of multiplying the data stored in the first shift registers 1 by 16 and adding the 4 bits of the data stored in the second shift registers 2. The output data DO of 4 bits are stored in the D-F/F 5 in the first half of the cycle of shift clocks SCK1 and stored in the first shift registers 1 in the second half. While the second shift registers 2 perform a shift operation for one time, the first shift registers 1 are circulated for one time. |
