Standard Cell Pin Routing for Orientation Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In standard cell designs for integrated circuits, the alignment of cell pins with routing tracks is disrupted when cells are flipped about their axis, leading to inefficiencies in routing connections due to the need for off-track wiring, which increases congestion and design time.
Innovation Solution
Standard cells with cell pins wider than the minimum metal width are designed to maintain alignment with routing tracks in both normal and flipped orientations, allowing for efficient on-track connections regardless of the cell's orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If standard cells are flipped about their axis to achieve flexible layout arrangements, then adaptability is improved, but alignment between cell pins and routing tracks is disrupted causing routing congestion
Solution Approach 1:
The patent applies asymmetry by making the cell pin width asymmetric relative to the routing track width. Specifically, the cell pin is designed wider than the minimum metal width to ensure that when cells are flipped, the pins still maintain proper alignment with the routing tracks. This asymmetric design (pin width > track width) allows the pin to accommodate the track centerline regardless of cell orientation, thus maintaining alignment flexibility while preventing routing congestion.
2Productivity
If cell pins are made wider than minimum metal width to maintain alignment with routing tracks, then routing efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by modifying the cell pin width parameter from the minimum metal width to a larger value. This parameter change ensures that the pin width is sufficient to accommodate the routing track centerline in both normal and flipped cell orientations. By changing this critical dimension parameter, the design achieves improved routing efficiency and alignment robustness without imposing excessive precision requirements, as the wider pin provides a larger tolerance margin.
Data Source
AI summary
Cells designed to accommodate metal routing tracks having a pitch that is an odd multiple of a manufacturing grid. The cells includes cell pins that are located within the cell based on the offsets of the routing tracks relative to the cell boundaries. The cell pins are wider than wires that are routed along the metal routing tracks. The standard cell may be placed in a layout in either a normal orientation or in a flipped orientation. In both orientations, the cell pins are aligned with the wires that are routed along the metal routing tracks.