Single Cycle Execution of Immediate Instructions
Original Publication Date: 1980-Dec-01
Included in the Prior Art Database: 2005-Feb-14
This article describes the implementation of IBM System/370 immediate instructions using a new and separate logical unit to reduce execution time. Previously the execution of the immediate instructions NI, OI, and XI required 2 cycles. The first cycle was to perform the logical function in a normal data path logical unit, and the second cycle was used to gate the result through a shifter to a cache input register.