read_checkpoint -incremental command assigns two cell properties
which are useful for analyzing incremental flow results using scripts or interactive
- A boolean property on cell, port, net, and pin objects. The property is set
to TRUE on the respective object if any of the following incremental data is
- A cell placement
- A package pin assignment for a port
- Any portion of the routing for a net
- Routing to a pin
- A string property on cells and nets denoting the reuse status after
incremental placement and routing.
Possible values for cells are:
- Discarded placement to improve timing
- Discarded illegal placement due to netlist changes
Possible values for nets are:
- A Boolean property assigned to a primitive-level cell. The property is set to TRUE on leaf cells that have matching leaf cells in the reference design. Matching cells are eligible for placement reuse.
Tip: Xilinx has published several applications in XHUB, in the Incremental Compile package. These applications include visualization of placement and routing reuse when analyzing critical path and other design views. Also included is an application for automatic Incremental Compile for the project flow, which automatically manages reference checkpoints for incremental design runs.