Access look-aside facility

摘要

An Access List Entry Token (ALET) access look-aside facility is used to look at all entries in the access Look-Aside Buffer (ALB) and select a Segment Table Destination (STD) for use in Dynamic Address Translation (DAT). At the same time that address generation is done to form the virtual address used for DAT, the content of the access register (i.e., the ALET) to be used for the access is sent to the ALB. When the AR-specified STD is to be used for DAT, the ALET sent to the ALB is simultaneously compared with all the ALETs in the ALB. If the ALET compares with an ALET in an ALB entry, the STD associated with that entry is selected for use in the storage access.