Layout for Digital Circuits

Question

Provide some significant Design methods you could follow when doing the Layout for Digital Circuits?

Answer 1

a) Within the digital design, choose height of the standard cells you wishes to layout. It depends on the size of your transistors. Have logical width for VDD and GND metal paths. Managing the uniform height for all cells is too significant as this shall help you to use the place route tool simply and also if you want to do the manual connection of all blocks it saves on lot of the area.

b) Utilize one metal in one direction only; this does not valid for the metal 1. Let you are using the metal 2 in order to do horizontal connections, then utilize the metal 3 for vertical connections, metal 4  for horizontal, metal 5 vertical and so on.

c) Keep as much substrate contact as possible within the empty spaces of layout.

d) Do not employ poly over the long distances since it has large resistances in case you have no other choice.

e) Employ the fingered transistors as and when you feel essential.