Preempt/Resume Mechanism for Processor Address Key Register Changes
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
This article describes a technique which provides a simple interrupt preempt/resume mechanism for tracking temporary Address Key Register (AKR) state changes during execution of an interruptible instruction such as the variable field length (VFL) instructions of a processor. A Set AKR From Address Key Table (SFAKT) instruction has two main subfunctions which are to set AKR values from AKR TABLE entries as follows: 1. Set AKR for one instruction only (referred to below as SFAKT Temporary). 2. Set AKR until next Set AKR instruction (referred to below as SFAKT Permanent). The processor has instructions which are interruptible because they are long running (timewise), such as the VFL instructions.