During placement, following three stages happens: Global Placement Refine Placement (Legalization) Detailed Placement Global Placement Global placement is very first stage of the placement where cells are placed inside the core area for the first time looking at the timing…
Pre-Placement Sanity Checks Before going for the placement of these standard cells, we need to have some checks known as pre-placement sanity checks as mentioned below. We perform these sanity checks at pre-placement stage of the design. Floating pins in…
What is Placement? Once we are done with the floorplan after placing all the physical cells inside the core boundary, we are left with standard cells which are still sitting out of the core design area. Now we need to…
Pin Placement Pin Placement details basically come from the TOP level design where we are having information to place pins according to the interaction with other HMs. We need to define edge, layer and location before placing pins. After pin…
Power Ground Grid Insertion The step of power-ground grid insertion is also known as stripegen. There are mainly four things we do during the stripegen step: Add Ring Add Stripe Create special route Add VIAs PG ring and stripes…
Power Switch Cell Placement Power switch cells are physical only cells. Basically power switches are defined in UPF w.r.t power domains present in the design. We need power switch in the design to control the power depending upon the power…
Tap Cell Placement: Well Tap cells are physical only cells which are placed in the design to avoid latch-up condition and maintain VDD and VSS NWELL continuity. Latch-up condition: Latch-up basically means a short circuit condition between power and ground.…
What is Boundary Cap (End Cap) ? Boundary cap cells are physical only cells. These cells are placed at the periphery of the core and power domain. Boundary cap cells are placed just after macro placement in the floorplan flow.…
Level Shifter Cell: In most of the Low Power Designs, there are one or more power domains where we have more power domains which operates at different voltage level in a single partition. In this case, we need different…
Retention Flops: These cells are special flops with multiple power supply. They are typically used as a shadow register to retain their value even if the block in which they are residing is shut down. All the paths leading…