Overheads of 4-port over 2-port SRAM
 

Hi,
It's really technology and layout-style dependent inthe cell based
design. However, I am wondering if there are some rule-of-thumb rules
that can be adopted to quickly show the overheads (area, energy and
latency) if I would like to use 4-port ram instead of the 2-port one in
my system.

Any comments, or point to research papers will be highly appreciated.
Thanks a lot!