OpenROAD Tcl Usage (global_placement)#
global_placement
[-skip_initial_place]
[-incremental]
[-bin_grid_count grid_count]
[-density density]
[-init_density_penalty init_density_penalty]
[-init_wirelength_coef init_wirelength_coef]
[-min_phi_coef min_phi_coef]
[-max_phi_coef max_phi_coef]
[-overflow overflow]
[-initial_place_max_iter max_iter]
[-initial_place_max_fanout max_fanout]
[-verbose_level verbose_level]
Flow Control#
skip_initial_place : Skip the initial placement (BiCGSTAB solving) before Nesterov placement. IP improves HPWL by ~5% on large designs.
incremental : Enable the incremental global placement. Users would need to tune other parameters (e.g. init_density_penalty) with the pre-placed solutions.
Tuning Parameters#
bin_grid_count : Set bin grid’s count manually. Default: Defined by internal algorithm. [64,128,256,512,…, int]
density : Set target density. Default: 0.70 [0-1, float]
init_density_penalty : Set initial density penalty. Default : 8e-5 [1e-6 - 1e6, float]
min_phi_coef : Set pcof_min(µ_k Lower Bound). Default: 0.95 [0.95-1.05, float]
max_phi_coef : Set pcof_max(µ_k Upper Bound). Default: 1.05 [1.00-1.20, float]
overflow : Set target overflow for termination condition. Default: 0.1 [0-1, float]
Other Options#
verbose_level [0-10, int] : Set verbose level for RePlAce. Default: 1
Note that all of the TCL commands are defined in the …/src/replace.tcl and …/src/replace.i.