Arithmetic logic unit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current computer architectures face inefficiencies in computational throughput for real-time image processing in driver assistance systems, particularly in handling large datasets without proportionally increasing register width and memory bandwidth.
Innovation Solution
The implementation of a SIMD arithmetic logic unit (ALU) with multiple data lanes that perform pairwise computations on input data, reducing output bits through bit reduction operations, and utilizing global control for efficient routing and function selection, allowing for operations like addition, subtraction, multiplication, and relational operations without storing intermediate results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple data lanes with functional units are implemented to increase computational throughput, then processing speed improves, but device complexity increases
Solution Approach 1:
The ALU is divided into multiple independent data lanes (first data lane, second data lane, etc.), each containing functional units that can operate independently. This segmentation allows parallel processing of multiple data elements simultaneously, increasing computational throughput while keeping each lane's complexity manageable
Solution Approach 2:
Each data lane contains functional units that can perform multiple operations (addition, subtraction, multiplication, division, logical operations) on different data types. The same functional units handle various computational tasks, reducing the need for dedicated hardware for each operation and thereby controlling device complexity
2Productivity
If bit reduction operations are performed to reduce output bits, then data processing efficiency improves, but information loss increases
Solution Approach 1:
The bit reduction operation changes the parameter of output data width from N bits to M bits (where M < N). This parameter change enables more compact data representation and faster processing, while the selective reduction maintains essential information by preserving the most significant bits that carry the most important data
3Adaptability or versatility
If global control block is implemented to manage routing and function selection, then operational flexibility improves, but control complexity increases
Solution Approach 1:
The global control block serves multiple functions: selecting active data lanes, choosing operational modes (addition, subtraction, multiplication, etc.), and controlling data routing. This multi-functionality consolidates control logic into a single unit, improving operational flexibility while avoiding the need for separate control circuits for each function
Solution Approach 2:
The global control block dynamically adjusts the configuration of data lanes and functional units based on the current computational requirements. It can enable or disable specific lanes, select different operations, and route data differently for each computational task, providing adaptability without requiring hardware reconfiguration
4Quantity of substance
If intermediate results are not stored to reduce memory bandwidth requirements, then memory usage decreases, but computational accuracy may be affected
Solution Approach 1:
The essential information is extracted and preserved in the reduced M-bit output format, while removing redundant less significant bits. This extraction process maintains the critical computational results needed for accuracy while eliminating data that would consume memory bandwidth without contributing to the final result
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An arithmetic logic unit (320) including a first routing grid (408) connected to multiple data lanes (400) to drive first data to the data lanes (400). A second routing grid (412) is connected to the data lanes (400) to drive second data to the data lanes (400). Each of the data lanes (400) include multiple, e.g. N, functional units with first inputs from the first routing grid and second inputs from the second routing grid. The functional units compute pairwise a function of the respective first data on the respective first inputs and the respective second data on the respective second inputs. Each of the data lanes include a reduction unit with inputs adapted to receive K' bits per word from the functional units. The reduction unit is configured to perform a reduction operation configured to output an output result having a reduced number J' bits per word, wherein J' is less than N multiplied by K'.