Merge pull request #3064 from jeffng-or/at-cts-buf-list

added CTS_BUF_LIST flow variable & prep for CTS arg fixes

Author: maliberty

docs/user/FlowVariables.md

@@ -75,6 +75,7 @@ configuration file.
 | <a name="CORNER"></a>CORNER| PVT corner library selection. Only available for ASAP7 and GF180 PDKs.| | |
 | <a name="CTS_ARGS"></a>CTS_ARGS| Override `clock_tree_synthesis` arguments.| | |
 | <a name="CTS_BUF_DISTANCE"></a>CTS_BUF_DISTANCE| Distance (in microns) between buffers.| | |
+| <a name="CTS_BUF_LIST"></a>CTS_BUF_LIST| List of cells used to construct the clock tree.| | |
 | <a name="CTS_CLUSTER_DIAMETER"></a>CTS_CLUSTER_DIAMETER| Maximum diameter (in microns) of sink cluster.| 20| |
 | <a name="CTS_CLUSTER_SIZE"></a>CTS_CLUSTER_SIZE| Maximum number of sinks per cluster.| 50| |
 | <a name="CTS_SNAPSHOT"></a>CTS_SNAPSHOT| Creates ODB/SDC files prior to clock net and setup/hold repair.| | |
@@ -304,6 +305,7 @@ configuration file.
 - [CELL_PAD_IN_SITES_DETAIL_PLACEMENT](#CELL_PAD_IN_SITES_DETAIL_PLACEMENT)
 - [CTS_ARGS](#CTS_ARGS)
 - [CTS_BUF_DISTANCE](#CTS_BUF_DISTANCE)
+- [CTS_BUF_LIST](#CTS_BUF_LIST)
 - [CTS_CLUSTER_DIAMETER](#CTS_CLUSTER_DIAMETER)
 - [CTS_CLUSTER_SIZE](#CTS_CLUSTER_SIZE)
 - [CTS_SNAPSHOT](#CTS_SNAPSHOT)

flow/designs/asap7/riscv32i/config.mk

@@ -28,3 +28,6 @@ export IO_CONSTRAINTS     = $(DESIGN_HOME)/$(PLATFORM)/$(DESIGN_NICKNAME)/io.tcl
 export MACRO_PLACE_HALO    = 2 2
 
 export TNS_END_PERCENT   = 100
+
+export CTS_CLUSTER_SIZE = 10
+export CTS_CLUSTER_DIAMETER = 50

flow/designs/nangate45/bp_be_top/config.mk

@@ -25,6 +25,8 @@ export MACRO_PLACE_HALO = 10 10
 export PLACE_DENSITY_LB_ADDON = 0.10
 export TNS_END_PERCENT        = 100
 
+export CTS_CLUSTER_SIZE = 30
+export CTS_CLUSTER_DIAMETER = 50
 export SYNTH_MINIMUM_KEEP_SIZE = 3000
 
 export FASTROUTE_TCL = $(DESIGN_HOME)/$(PLATFORM)/$(DESIGN_NAME)/fastroute.tcl

flow/designs/sky130hd/aes/config.mk

@@ -18,3 +18,5 @@ export FASTROUTE_TCL = $(DESIGN_HOME)/$(PLATFORM)/$(DESIGN_NICKNAME)/fastroute.t
 
 export REMOVE_ABC_BUFFERS = 1
 
+export CTS_CLUSTER_SIZE = 20
+export CTS_CLUSTER_DIAMETER = 50

flow/designs/sky130hd/ibex/config.mk

@@ -52,3 +52,6 @@ export TNS_END_PERCENT = 100
 export FASTROUTE_TCL = $(DESIGN_HOME)/$(PLATFORM)/$(DESIGN_NICKNAME)/fastroute.tcl
 
 export REMOVE_ABC_BUFFERS = 1
+
+export CTS_CLUSTER_SIZE = 20
+export CTS_CLUSTER_DIAMETER = 50

flow/designs/sky130hs/aes/config.mk

@@ -13,3 +13,7 @@ export PLACE_DENSITY_LB_ADDON = 0.25
 export TNS_END_PERCENT = 100
 
 export REMOVE_ABC_BUFFERS = 1
+
+export CTS_CLUSTER_SIZE = 10
+export CTS_CLUSTER_DIAMETER = 50
+

flow/designs/sky130hs/jpeg/config.mk

@@ -14,3 +14,5 @@ export CORE_MARGIN = 2
 export PLACE_DENSITY_LB_ADDON = 0.25
 export TNS_END_PERCENT = 100
 
+export CTS_CLUSTER_SIZE = 30
+export CTS_CLUSTER_DIAMETER = 50

flow/scripts/cts.tcl

@@ -18,9 +18,12 @@ set cts_args [list \
           -sink_clustering_enable \
           -balance_levels]
 
+# TODO: The first three are no-ops since the arg order is wrong, but hard to get
+# through CI since nine designs change metrics and the PR is blocked
 append_env_var cts_args -distance_between_buffers CTS_BUF_DISTANCE 1
 append_env_var cts_args -sink_clustering_size CTS_CLUSTER_SIZE 1
 append_env_var cts_args -sink_clustering_max_diameter CTS_CLUSTER_DIAMETER 1
+append_env_var cts_args CTS_BUF_LIST -buf_list 1
 
 if {[env_var_exists_and_non_empty CTS_ARGS]} {
   set cts_args $::env(CTS_ARGS)

flow/scripts/variables.yaml

@@ -718,6 +718,11 @@ CTS_BUF_DISTANCE:
     Distance (in microns) between buffers.
   stages:
     - cts
+CTS_BUF_LIST:
+  description: |
+    List of cells used to construct the clock tree.
+  stages:
+    - cts
 CTS_CLUSTER_DIAMETER:
   description: >
     Maximum diameter (in microns) of sink cluster.