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Reduce the M4 & M7 PDN pitch for gcd to accommodate its small area #3354

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Merged
maliberty merged 1 commit into from
Jul 23, 2025
Merged

Reduce the M4 & M7 PDN pitch for gcd to accommodate its small area #3354

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3 changes: 3 additions & 0 deletions flow/designs/nangate45/gcd/config.mk
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Original file line number Diff line number Diff line change
Expand Up @@ -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)/$(DESIGN_NAME)/grid_strategy-M1-M4-M7.tcl
22 changes: 22 additions & 0 deletions flow/designs/nangate45/gcd/grid_strategy-M1-M4-M7.tcl
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@@ -0,0 +1,22 @@
####################################
# global connections
####################################
add_global_connection -net {VDD} -inst_pattern {.*} -pin_pattern {^VDD$} -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}