| 摘要 |
PURPOSE:To eliminate the need to transfer a data block to be updated or corrected to a main storage device and reduce the load on a system bus by allocating memory addresses having the same level with a main storage device in the buffer memory in a disk controller. CONSTITUTION:When a CPU alters data in a magnetic disk device 6, a buffer memory control circuit 102 transfers data from a designated position in the magnetic disk device 6 to the buffer memory 100 in response to the issue of a data read-in command from the CPU. Then, the CPU issues a bank address designating command and a bank address 109 is stored in a bank address register 105 with a bank address latch signal 110 obtained by the decoding of a command decoder 106. Then, 1,024 bytes from an address 9000 are allocated in the buffer memory 100 between 0000-7FFF of the main storage device 3, and after the bank address 109 is set to 9000, the CPU accesses the buffer memory 100 as the main storage device 3.
|
