US Patent 8183639 Dual port static random access memory cell layout

A dual port static random access memory cell has pull-down transistors, pull-up transistors, and pass transistors. A first active region has a first pull-down transistor coupled to a true data node, a second pull-down transistor coupled to a complementary data node; a first pass transistor coupled to the true data node, and a second pass transistor coupled to the complementary data node. A second active region has the same size and shape as the first active region and has a third pull-down transistor coupled in parallel to the first-pull down transistor, a fourth pull-down transistor coupled in parallel to the second pull-down transistor; a third pass transistor coupled to the true data node, and a fourth pass transistor coupled to the complementary data node. A first pull-up transistor and a second pull-up transistor are located between the first and second active regions.