Patent attributes
What is provided is an enhanced dynamic address translation facility. In one embodiment, a virtual address to be translated and an initial origin address of any one of a region first table, a region second table, a region third table, or a segment table are obtained. Based on the obtained initial origin address, a segment table entry is obtained which contains a format control and DAT protection fields. If the format control field is enabled, obtaining from the translation table entry a segment-frame absolute address of a large block of data in main storage. The segment-frame absolute address is combined with a page index portion and a byte index portion of the virtual address to form a translated address of the desired block of data. If the DAT protection field is not enabled, fetches and stores are permitted to the desired block of data addressed by the translated virtual address.