End of line spacing

end of line spacing代表着一类drc问题，根据tech file的相关约束确定具体的spacing要求。

end of line spacing指的是end of line edge与相邻的同层金属的spacing要求，其中end of line edge定义为两个相邻凸角的公共边宽度小于阈值时被称为end of line edge，如下图所示，此时end of line edge所在的金属线就被称为end of line wire。

根据tech file约束具体细分可以分为以下情况:

• End-of-Line to End-of-Line Spacing Rule

• One-Neighbor End-to-End Table-Based Spacing Rule

• One-Neighbor End-of-Line Spacing Rule

• Preferred and Nonpreferred End-of-Line Spacing Rule

• Two-Neighbor End-of-Line Spacing Rule

• Three-Neighbor End-of-Line Spacing Rule

• Three-Neighbor End-of-Line Cap Rule

• Single-Side Isolated Neighbor End-of-