Placement

Routing congestion in VLSI explained for physical design engineers: how global routers measure GCell capacity, demand and overflow, cell density vs pin density, global, local and layer congestion, floorplan, logic and placement causes, fixes with halos, partial blockages and cell padding, the timing impact, a debugging flowchart and interview Q&As.

Scan chain reordering in VLSI physical design explained: why synthesis scan order wastes wirelength, what the scan DEF (START/STOP, FLOATING, ORDERED, PARTITION, MAXBITS) allows, clock-domain, edge-order and lockup-latch rules, chain balancing, scan shift hold timing, verification and ATPG regeneration, with illustrative examples, a debugging flowchart and interview Q&As.

How multi-bit flip-flops save clock power, which flops can be banked, the timing and useful-skew trade-offs, and a practical method for debanking, with worked examples.

What PODE and CPODE are, how single and double diffusion breaks differ, and what cell-edge rules mean for placement, legalization, fillers and ECOs at FinFET and GAA nodes.

Understanding the Performance (Timing) Before going to understand the performance (timing), lets understand how timing is getting checked. At placement stage we have the placement of cells information, but we don’t have connection information in between the cells so how the timing analysis will be, and which layers will help complete routing. As we know […]

What is Placement Optimization? Depending on the stages of the design, optimization can include the following operations: Secondary PG Routing As we know there are many partitions now a days, so we are dealing with UPF and number of power domains. We use AON cells (we discussed in Floorplan section) in the gated partition to […]