What should Cell Height be?
When routing was limited to just two layers of metal, wanted short cells
- Routing was M1 horizonal, M2 vertical
- Most of the routing was done in the channels between cell rows
- Short cells minimized Row to Row spacing
With over the cell routing (HVH), tall cells now slide under the routing, and channels have disappeared.
- Taller cells allow for multiple drive strength cells which is important for modern synthesis tools.