I found the net length info in Allegro like that,
/*
Total Etch Length: 2391.854 MIL
Total Manhattan Length: 2758.035 MIL
Percent Manhattan: 86.72%
*/
However I do not konw the difference, may you give me some ref?
Etch length is the actual length of your trace from the beginning point to the end point.
Manhattan length is the distance you would travel from the beginning point to the end point if you can only move in straight line paths along the x or y axis - or traveling the sides of a right triangle instead of the hypotenuse. (Like walking along the sidewalks of Manhattan, New York.)
The percentage of Manhattan is telling you how well you did in reducing the length of the trace overall - or how close you came to a direct path from beginning to end along the hypotenuse of the triangle instead of right angle x and y axis paths along the sides.
Thank you for your help, and I found the equation 'Percent Manhattan' = 'Total Etch Length'/ '
Total Manhattan Length'.
Maybe we should make the 'Percent Manhattan' as small as possible, and what region is possible due to intuition?