From 41d45ac7bb77d40381009e538f5d96fa2e944aba Mon Sep 17 00:00:00 2001 From: Matt Liberty Date: Wed, 23 Jul 2025 16:55:26 +0000 Subject: [PATCH] Reduce the M4 & M7 PDN pitch for gcd to accommodate its small area Fixes The-OpenROAD-Project/OpenROAD#7784 Signed-off-by: Matt Liberty --- flow/designs/nangate45/gcd/config.mk | 3 +++ .../nangate45/gcd/grid_strategy-M1-M4-M7.tcl | 22 +++++++++++++++++++ 2 files changed, 25 insertions(+) create mode 100644 flow/designs/nangate45/gcd/grid_strategy-M1-M4-M7.tcl diff --git a/flow/designs/nangate45/gcd/config.mk b/flow/designs/nangate45/gcd/config.mk index 1b61b78af4..d7fc7a8bdd 100644 --- a/flow/designs/nangate45/gcd/config.mk +++ b/flow/designs/nangate45/gcd/config.mk @@ -12,3 +12,6 @@ export CORE_UTILIZATION ?= 55 export PLACE_DENSITY_LB_ADDON = 0.20 export TNS_END_PERCENT = 100 export REMOVE_CELLS_FOR_EQY = TAPCELL* + +# This needs a smaller pitch to accomodate a small block +export PDN_TCL ?= $(DESIGN_HOME)/$(PLATFORM)/$(DESIGN_NAME)/grid_strategy-M1-M4-M7.tcl diff --git a/flow/designs/nangate45/gcd/grid_strategy-M1-M4-M7.tcl b/flow/designs/nangate45/gcd/grid_strategy-M1-M4-M7.tcl new file mode 100644 index 0000000000..124e9a32cc --- /dev/null +++ b/flow/designs/nangate45/gcd/grid_strategy-M1-M4-M7.tcl @@ -0,0 +1,22 @@ +#################################### +# global connections +#################################### +add_global_connection -net {VDD} -inst_pattern {.*} -pin_pattern {^VDD$} -power +add_global_connection -net {VDD} -inst_pattern {.*} -pin_pattern {^VDDPE$} +add_global_connection -net {VDD} -inst_pattern {.*} -pin_pattern {^VDDCE$} +add_global_connection -net {VSS} -inst_pattern {.*} -pin_pattern {^VSS$} -ground +add_global_connection -net {VSS} -inst_pattern {.*} -pin_pattern {^VSSE$} +global_connect +#################################### +# voltage domains +#################################### +set_voltage_domain -name {CORE} -power {VDD} -ground {VSS} +#################################### +# standard cell grid +#################################### +define_pdn_grid -name {grid} -voltage_domains {CORE} +add_pdn_stripe -grid {grid} -layer {metal1} -width {0.17} -pitch {2.4} -offset {0} -followpins +add_pdn_stripe -grid {grid} -layer {metal4} -width {0.48} -pitch {28.0} -offset {2} +add_pdn_stripe -grid {grid} -layer {metal7} -width {1.40} -pitch {15.0} -offset {2} +add_pdn_connect -grid {grid} -layers {metal1 metal4} +add_pdn_connect -grid {grid} -layers {metal4 metal7}