The SKY130HD enablement available in the OpenROAD-flow-script[GitHub repo](https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/tree/master/flow/platforms/sky130hd) is a five-metal stack enablement. However, memory macro has blockage till metal four, so a five-metal stack is not enough to route our macro dominant testcases.
The SKY130HD enablement available in the OpenROAD-flow-scripts [GitHub repo](https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/tree/master/flow/platforms/sky130hd) is a five-metal stack enablement. However, memory macros have blockages till metal four, so a five-metal stack is not enough to route our macro dominant testcases. So we extended SKY130HD to a nine-metal fake layer stack in the OpenROAD-flow-scripts [GitHub repo](https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/tree/master/flow/platforms/sky130hd_fakestack).
In this enablement, each of the five routing layers and four cut layers have different lef properties (.e.g, minimum spacing, width, enclosure, etc.). Consider the five layers of the metal stack are Ma, Mb, Mc, Md and Me, and the stack configuration is named as 1Ma_1Mb_1Mc_1Md_1Me. We replicate the first four metal layers to generate the nine-metal layer FakeStack where the configuration is 2Ma_2Mb_2Mc_2Md_1Me. We use this nine-metal layer FakeStack of SKY130HD as one of the enablements. The [getTechLef.tcl](./lef/genTechLef.tcl) can be used to generate a FakeStack of layer configuration x<sub>1</sub>Ma_x<sub>2</sub>Mb_x<sub>3</sub>Mc_x<sub>4</sub>Md_1Me, where x<sub>i</sub> is greater or equal to one.
