| 摘要 |
PURPOSE:To improve transfer efficiency, by performing ordinary data transfer with plural bytes width, and performing data transfer between a processor part with one byte width. CONSTITUTION:When the data transfer is performed between the processor part 2 and an external device, a byte width selection circuit 4 issues instruction to fetch an input data with one byte width, and also, issues the instruction to select only one byte of an output from a data buffer part 1, to a byte width conversion circuit 3 by the instruction from the above stated processor part 2. Thereby, the data buffer part 1 fetches the only to one byte out of plural bytes, and insert dummy data to remaining bytes. Meanwhile, when the ordinary data transfer between the above stated external device and an internal circuit is performed, no instruction from the above stated processor part is issued. |
