Bump microwatt PLACE_DENSITY 0.2 -> 0.25

Tightening rule cts__timing__setup__ws__pre_repair from -4.24 to -3.72.
Tightening rule cts__timing__setup__ws__post_repair from -4.24 to -3.72.
Tightening rule cts__design__instance__count__setup_buffer from 7558 to 7557.
Tightening rule cts__design__instance__count__hold_buffer from 7558 to 7557.
Tightening rule globalroute__timing__setup__ws from -1.74 to -1.58.
Tightening rule finish__timing__setup__ws from -5.82 to -1.95.
Tightening rule finish__timing__drv__max_slew_limit from -5.04 to -5.02.
Updating failing rule finish__timing__drv__max_cap_limit from -1.73 to -4.34.
Tightening rule finish__timing__wns_percent_delay from -32.78 to -15.72.

Signed-off-by: Matt Liberty <[email protected]>

Author: maliberty

flow/designs/sky130hd/microwatt/config.mk

@@ -11,7 +11,7 @@ export SDC_FILE      = ./designs/$(PLATFORM)/$(DESIGN_NICKNAME)/constraint.sdc
 export DIE_AREA   = 0 0 2920 3520
 export CORE_AREA  = 10 10 2910 3510
 
-export PLACE_DENSITY ?= 0.20
+export PLACE_DENSITY ?= 0.25
 
 export microwatt_DIR = ./designs/$(PLATFORM)/$(DESIGN_NICKNAME)
 
@@ -31,4 +31,4 @@ export CTS_CLUSTER_SIZE = 30
 
 export export SETUP_SLACK_MARGIN = 0.2
 
-export GLOBAL_ROUTE_ARGS=-congestion_iterations 100 -verbose
+export GLOBAL_ROUTE_ARGS=-congestion_iterations 100 -verbose