Set and Copy Address Key Register Circuitry for Computer Processors
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
A technique is described whereby a circuit, imbedded in computer architecture, provides set and copy address key register (AKR) manipulations. The circuit enables a processor, similar to an IBM Series/1, to transfer both partial and full bit fields from various locations in the register. The concept is an improvement over previous methods which required sorting and reassembling the bits during several microcycles. The 16-bit AKR register is divided into three 5-bit fields, where field 1 is the Operand 1 key, field 2 is the Operand 2 key, and field 3 is the instruction space key. One of the five bits of each space key is located in a separate field of the AKR (bits 1, 2, and 3). When a 5-bit field is to be copied, the five bits must be assembled as a 5-bit field and stored in the low-order five bits of a 16-bit word.