| 摘要 |
PURPOSE:To easily uniform the digits of even data which is not at a word boundary and to easily perform arithmetic on word-width basis by operating a byte ring shifter by using information of the low-order digit bits of the address of the date. CONSTITUTION:The function of the byte ring shifter 6 is set to a 2-byte exchange mode by a function determining block 7 on the basis of the two least significant digit bits of AS1 and AS2 stored in the 1st data register 3 and then the byte ring shifter 6 operates as a shifter which exchanges two bytes. Then, the starting 1-byte data A1 of data A is stored in the 1st data register 3 and its contents are further stored in the 2nd data register 4 through the byte ring shifter 6. When the starting 4-byte data B1 of data B is read in the 1st data register 3, an arithmetic block 11 performs arithmetic as it is.
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