| 摘要 |
PURPOSE:To transfer a data from an optional unit to other unit not via a main memory and a bus line by issuing one instruction from a processing unit. CONSTITUTION:When a data transfer command (f) is given from the processing unit 2, a unit number register 5 and a read/write control circuit 4 read a data from a unit 6 (UNO) and store it to a buffer memory 3. When the data read is finished from the UNO, the circuit 4 transmits a read end signal (i) to a data transfer control circuit 7. The circuit 7 receives the signal (i) and issues a unit control signal (h) and a read/write control signal (g) to the circuit UN1. The register 5 and the circuit 4 uses a select signal (e) and a write signal (d) to write a data stored in the memory 3 to the UN1 to complete the data transfer. Thus, the data is transferred not via the main memory 1 and the bus line (a) to prevent the reduction in the system efficiency.
|
