| 摘要 |
PURPOSE:To transfer data efficiently with a microprogram without reserving a data buffer in an input/output controller with respect to the asynchronous data transfer processing between a peripheral device and a storage device. CONSTITUTION:A data transfer address setting instruction is issued before software issues a read instruction to a device 51. A microprogram control part 11 decodes the data transfer address setting instruction and reads the first - the fourth lengths (731-734) and the first - the fourth transfer addresses (741-744) from a main storage area and sets data to a local memory 13 of an input/output controller 2. Next, the first - the fourth busy/free discriminator registers 721-724 are initialized to free state '0', and the first and the second transfer address pointers 711 and 712 existing in an area beginning with an address (a) are initialized to an address (b). |
