Unidirectional Rotator Shift Value Modification Logic

Solution Overview

Problem

Current processors require additional power and space to execute bi-directional shift and rotate instructions, leading to increased latency and resource consumption due to the need for separate left and right rotators.

Innovation Solution

A unidirectional rotator with a control unit that modifies shift values specified by register-based instructions to achieve the equivalent result in the opposite direction, allowing data to be shifted or rotated efficiently in one direction, thereby bypassing the need for explicit opposite direction operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate left and right rotators are incorporated to execute bi-directional shift and rotate instructions, then the processor can perform shift and rotate operations in both directions, but this consumes additional power and requires more area or space

Engineering Contradiction:

Improvebi-directional shift and rotate capabilityVSAvoidprocessor area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

A single unidirectional rotator is designed to perform multiple functions by accepting modified shift values from the control unit. The rotator can execute both left and right shift/rotate operations by receiving appropriately adjusted shift amounts, eliminating the need for separate dedicated rotators for each direction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control unit acts as an intermediary between the instruction decoder and the unidirectional rotator. It modifies the shift value from instructions to generate equivalent shift amounts for the unidirectional rotator, enabling bi-directional operations through a single hardware component.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If separate left and right rotators are incorporated to execute bi-directional shift and rotate instructions, then the processor can perform shift and rotate operations in both directions, but this consumes additional power

Engineering Contradiction:

Improvebi-directional shift and rotate capabilityVSAvoidprocessor power consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

A single unidirectional rotator is designed to perform multiple functions by accepting modified shift values from the control unit. The rotator can execute both left and right shift/rotate operations by receiving appropriately adjusted shift amounts, eliminating the need for separate dedicated rotators for each direction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control unit acts as an intermediary between the instruction decoder and the unidirectional rotator. It modifies the shift value from instructions to generate equivalent shift amounts for the unidirectional rotator, enabling bi-directional operations through a single hardware component.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Area of stationary object

If a unidirectional rotator is used with control unit logic to modify shift values, then processor area and power consumption are reduced, but latency may increase due to the additional modification logic

Engineering Contradiction:

Improveprocessor areaVSAvoidshift operation latency

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The control unit performs shift value modification in advance during the instruction decode stage, before the actual shift operation is executed. This preliminary modification ensures that the unidirectional rotator receives the correct shift amount without requiring additional processing time during the execution stage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit acts as an intermediary between the instruction decoder and the unidirectional rotator. It modifies the shift value from instructions to generate equivalent shift amounts for the unidirectional rotator, enabling bi-directional operations through a single hardware component.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8335810B2Register-based shifts for a unidirectional rotator

Publication Date: 2012.12.18 QUALCOMM INC

AI summary

A processor having a unidirectional rotator configured to shift or rotate data in one direction is disclosed. The processor also includes a control unit having logic configured to modify a shift value specified by a registered-based shift, or rotate, instruction in an opposite direction, the modified shift value being usable by the rotator to shift, or rotate, the data in the one direction, and thereby, generate the same result as if the data in the rotator had otherwise been shifted, or rotated, in the opposite direction by the shift value originally specified by the registered-based instruction. The control unit is further configured to bypass the logic and provide to the rotator a shift value specified by a register-based instruction to shift, or rotate, the data in the one direction.