| 摘要 |
<p>An external memory control device, which is capable of reducing the time required for processing the writing and reading of data for the storage areas of an external memory device. The external memory control device includes a smallest sector number register and a largest sector number register which stores the smallest and the largest sector numbers, respectively, within a processing range that is designated by the track of a processing request signal from the central processing unit. A processing range detecting part detects whether the sector number read from the designated track is within the processing range, and means which stores, when the sector number read first from the designated track is within the processing range. The following sector number in the sector number register. Stores the smallest sector number when the sector number is outside the processing region and generates a discrimination signal which is turned on when the sector number read out and the sector number which is the stored contents of the sector number register coincide, and updates the stored contents of the sector number register to the next sector number. In this external memory control device, if the sector number read from the designated track is within the processing range, the processing start from the next sector, so that the holding of the operation until the arrival of the smallest sector number is no longer needed, and the time required for processing per track can be reduced. <IMAGE></p> |
