SRAM Word Line Routing for Balanced Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Static random access memory (SRAM) devices face performance issues due to unbalanced parasitic capacitance caused by varying lengths of word lines associated with address lines, leading to poor performance and inefficient design.
Innovation Solution
The solution involves arranging word lines and address lines in a memory device such that each address line has a consistent total length of word lines coupled to it, achieved by grouping word lines into sets and twisting address lines between these groups, thereby maintaining balanced parasitic capacitance while reducing redundant routings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If word lines are routed with varying lengths to different address lines, then routing flexibility is improved, but parasitic capacitance becomes unbalanced leading to poor performance
Solution Approach 1:
The patent applies equipotentiality by ensuring that all address lines have equal total lengths of word lines coupled to them, creating balanced parasitic capacitance. This is achieved by routing word lines in a systematic pattern where each address line receives the same total length, eliminating capacitance imbalances that would otherwise degrade performance.
2Reliability
If word lines are routed with consistent lengths to all address lines, then parasitic capacitance is balanced improving performance, but routing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the word line routing into systematic segments or groups. Word lines are organized in patterns where adjacent word lines are routed together, creating modular segments that are easier to manage. This segmentation approach maintains equal total lengths while reducing overall routing complexity through structured organization.
3Device complexity
If redundant routings are removed to simplify design, then device complexity is reduced, but parasitic capacitance balance may be affected
Solution Approach 1:
The patent applies parameter changes by systematically adjusting routing parameters such as word line lengths and routing paths. By changing these parameters in a controlled manner, the design achieves equal total lengths for all address lines while eliminating redundant routings. This parameter optimization maintains capacitance balance without unnecessary complexity.
Data Source
AI summary
A memory device includes a first plurality of program lines of a first group, a second plurality of program lines of a second group, and a plurality of address lines. The second plurality of program lines are disposed next to and are parallel to the first plurality of program lines. The plurality of address lines are coupled to the first plurality of program lines and the second plurality of program lines respectively. The plurality of address lines are twisted and are intersected with the first plurality of program lines and the second plurality of program lines in a layout view. At least two adjacent program lines of the first plurality of program lines or the second plurality of program lines have lengths different from each other. A method is also disclosed herein.