psm: add check for bterms option

src/psm/README.md

@@ -60,6 +60,7 @@ check_power_grid
     -net net_name
     [-floorplanning]
     [-error_file error_file]
+    [-dont_require_terminals]
 ```
 
 #### Options
@@ -69,6 +70,7 @@ check_power_grid
 | `-net` | Name of the net to analyze. Must be a power or ground net name. |
 | `-floorplanning` | Ignore non-fixed instances in the power grid, this is useful during floorplanning analysis when instances may not be properly placed. |
 | `-error_file` | File to write power grid errors to. |
+| `-dont_require_terminals` | If specified, this will skip checking if there are terminals on the net. |
 
 ### Write Spice Power Grid
 

src/psm/include/psm/pdnsim.h

@@ -121,7 +121,8 @@ class PDNSim : public odb::dbBlockCallBackObj
                          IRDropByPoint& ir_drop) const;
   bool checkConnectivity(odb::dbNet* net,
                          bool floorplanning,
-                         const std::string& error_file);
+                         const std::string& error_file,
+                         bool require_bterm);
   void setDebugGui(bool enable);
 
   void clearSolvers();

src/psm/src/ir_solver.cpp

@@ -128,7 +128,7 @@ PDNSim::IRDropByPoint IRSolver::getIRDrop(odb::dbTechLayer* layer,
   return ir_drop;
 }
 
-bool IRSolver::check()
+bool IRSolver::check(bool check_bterms)
 {
   const utl::DebugScopedTimer timer(logger_, utl::PSM, "timer", 1, "Check: {}");
   if (connected_.has_value()) {
@@ -137,6 +137,10 @@ bool IRSolver::check()
 
   // set to true and unset if it failed
   connected_ = true;
+  if (check_bterms && !checkBTerms()) {
+    reportMissingBTerm();
+    connected_ = false;
+  }
   if (!checkOpen()) {
     reportUnconnectedNodes();
     connected_ = false;
@@ -228,6 +232,28 @@ bool IRSolver::checkOpen()
   return true;
 }
 
+bool IRSolver::checkBTerms() const
+{
+  const utl::DebugScopedTimer timer(
+      logger_, utl::PSM, "timer", 1, "Check bterm: {}");
+
+  for (odb::dbBTerm* bterm : net_->getBTerms()) {
+    for (odb::dbBPin* bpin : bterm->getBPins()) {
+      if (bpin->getPlacementStatus().isPlaced()) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+void IRSolver::reportMissingBTerm() const
+{
+  logger_->error(
+      utl::PSM, 25, "{} does not contain any terminals", net_->getName());
+}
+
 IRSolver::ConnectivityResults IRSolver::getConnectivityResults() const
 {
   ConnectivityResults results;

src/psm/src/ir_solver.h

@@ -101,7 +101,7 @@ class IRSolver
 
   odb::dbNet* getNet() const { return net_; };
 
-  bool check();
+  bool check(bool check_bterms);
 
   void solve(sta::Corner* corner,
              GeneratedSourceType source_type,
@@ -156,6 +156,7 @@ class IRSolver
   odb::dbTech* getTech() const;
 
   bool checkOpen();
+  bool checkBTerms() const;
   bool checkShort() const;
 
   std::map<odb::dbInst*, Power> getInstancePower(sta::Corner* corner) const;
@@ -187,6 +188,7 @@ class IRSolver
       std::vector<std::unique_ptr<SourceNode>>& sources) const;
 
   void reportUnconnectedNodes() const;
+  void reportMissingBTerm() const;
   bool wasNodeVisited(const std::unique_ptr<ITermNode>& node) const;
   bool wasNodeVisited(const std::unique_ptr<Node>& node) const;
   bool wasNodeVisited(const Node* node) const;

src/psm/src/pdnsim.cpp

@@ -111,7 +111,7 @@ void PDNSim::analyzePowerGrid(odb::dbNet* net,
                               const std::string& error_file,
                               const std::string& voltage_source_file)
 {
-  if (!checkConnectivity(net, false, error_file)) {
+  if (!checkConnectivity(net, false, error_file, false)) {
     return;
   }
 
@@ -138,10 +138,11 @@ void PDNSim::analyzePowerGrid(odb::dbNet* net,
 
 bool PDNSim::checkConnectivity(odb::dbNet* net,
                                bool floorplanning,
-                               const std::string& error_file)
+                               const std::string& error_file,
+                               bool require_bterm)
 {
   auto* solver = getIRSolver(net, floorplanning);
-  const bool check = solver->check();
+  const bool check = solver->check(require_bterm);
   solver->writeErrorFile(error_file);
 
   if (debug_gui_enabled_) {

src/psm/src/pdnsim.i

@@ -99,10 +99,10 @@ insert_decap_cmd(const float target, const char* net_name)
 }
 
 bool
-check_connectivity_cmd(odb::dbNet* net, bool floorplanning, const char* error_file)
+check_connectivity_cmd(odb::dbNet* net, bool floorplanning, const char* error_file, bool dont_require_bterm)
 {
   PDNSim* pdnsim = getPDNSim();
-  return pdnsim->checkConnectivity(net, floorplanning, error_file);
+  return pdnsim->checkConnectivity(net, floorplanning, error_file, !dont_require_bterm);
 }
 
 void

src/psm/src/pdnsim.tcl

@@ -37,11 +37,13 @@ sta::define_cmd_args "check_power_grid" {
   -net power_net
   [-error_file error_file]
   [-floorplanning]
+  [-dont_require_terminals]
 }
 
 proc check_power_grid { args } {
   sta::parse_key_args "check_power_grid" args \
-    keys {-net -error_file} flags {-floorplanning}
+    keys {-net -error_file} \
+    flags {-floorplanning -dont_require_terminals}
 
   if { ![info exists keys(-net)] } {
     utl::error PSM 57 "Argument -net not specified."
@@ -53,8 +55,13 @@ proc check_power_grid { args } {
   }
 
   set floorplanning [info exists flags(-floorplanning)]
+  set dont_require_bterm [info exists flags(-dont_require_terminals)]
 
-  psm::check_connectivity_cmd [psm::find_net $keys(-net)] $floorplanning $error_file
+  psm::check_connectivity_cmd \
+    [psm::find_net $keys(-net)] \
+    $floorplanning \
+    $error_file \
+    $dont_require_bterm
 }
 
 sta::define_cmd_args "analyze_power_grid" {

src/psm/test/CMakeLists.txt

@@ -12,6 +12,8 @@ or_integration_tests(
     check_power_grid_floorplanning
     check_power_grid_macros
     check_power_grid_ok_disconnected
+    check_power_grid_require_bterms_fail
+    check_power_grid_require_bterms_pass
     corners
     corners_assign_power
     gcd_all_vss

src/psm/test/check_power_grid.tcl

@@ -4,4 +4,4 @@ source helpers.tcl
 
 read_lef Nangate45/Nangate45.lef
 read_def Nangate45_data/gcd.def
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals

src/psm/test/check_power_grid_disconnected.tcl

@@ -4,5 +4,5 @@ source helpers.tcl
 read_lef Nangate45/Nangate45.lef
 read_lef Nangate45_data/fakeram45_64x32.lef
 read_def Nangate45_data/check_power_grid_disconnected.def
-catch {check_power_grid -net VDD} err
+catch {check_power_grid -net VDD -dont_require_terminals} err
 puts $err

src/psm/test/check_power_grid_disconnected_macro.tcl

@@ -8,7 +8,8 @@ read_def asap7_data/riscv.def
 
 
 set error_report [make_result_file check_power_grid_disconnected_macro.rpt]
-catch {check_power_grid -net VDD -error_file $error_report} err
+catch {check_power_grid -net VDD -error_file $error_report \
+    -dont_require_terminals} err
 puts $err
 
 diff_files $error_report check_power_grid_disconnected_macro.rptok

src/psm/test/check_power_grid_floorplanning.tcl

@@ -3,4 +3,4 @@ source helpers.tcl
 
 read_lef Nangate45/Nangate45.lef
 read_def Nangate45_data/gcd_floorplanning.def
-check_power_grid -net VDD -floorplanning
+check_power_grid -net VDD -floorplanning -dont_require_terminals

src/psm/test/check_power_grid_macros.tcl

@@ -5,4 +5,4 @@ read_lef Nangate45_data/fakeram45_64x32.lef
 
 read_def check_power_grid_macros.def
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals

src/psm/test/check_power_grid_ok_disconnected.tcl

@@ -9,4 +9,4 @@ read_liberty Nangate45/Nangate45_typ.lib
 read_liberty Nangate45/fakeram45_64x32.lib
 
 read_def Nangate45_data/check_power_grid_ok_disconnected.def
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals

src/psm/test/check_power_grid_require_bterms_fail.ok

@@ -0,0 +1,8 @@
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0128] Design: gcd
+[INFO ODB-0130]     Created 54 pins.
+[INFO ODB-0131]     Created 624 components and 2752 component-terminals.
+[INFO ODB-0132]     Created 2 special nets and 1248 connections.
+[INFO ODB-0133]     Created 581 nets and 1504 connections.
+[ERROR PSM-0025] VDD does not contain any terminals
+PSM-0025

src/psm/test/check_power_grid_require_bterms_fail.tcl

@@ -0,0 +1,7 @@
+# Check that check_power_grid fails with missing terminals
+source helpers.tcl
+
+read_lef Nangate45/Nangate45.lef
+read_def Nangate45_data/gcd.def
+catch {check_power_grid -net VDD} err
+puts $err

src/psm/test/check_power_grid_require_bterms_pass.ok

@@ -0,0 +1,8 @@
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0128] Design: aes_cipher_top
+[INFO ODB-0130]     Created 390 pins.
+[INFO ODB-0131]     Created 19835 components and 101835 component-terminals.
+[INFO ODB-0132]     Created 2 special nets and 39670 connections.
+[INFO ODB-0133]     Created 18908 nets and 62165 connections.
+[INFO PSM-0040] All shapes on net VDD are connected.
+1

src/psm/test/check_power_grid_require_bterms_pass.tcl

@@ -0,0 +1,7 @@
+# Check that check_power_grid passes with terminals
+source helpers.tcl
+
+read_lef Nangate45/Nangate45.lef
+read_def Nangate45_data/aes_bterms.def
+catch {check_power_grid -net VDD -dont_require_terminals} err
+puts $err

src/psm/test/gcd_all_vss.tcl

@@ -9,7 +9,7 @@ set voltage_file [make_result_file gcd_all_vss-voltage.rpt]
 set em_file [make_result_file gcd_all_vss-em.rpt]
 set spice_file [make_result_file gcd_all_vss-spice.sp]
 
-check_power_grid -net VSS
+check_power_grid -net VSS -dont_require_terminals
 analyze_power_grid -vsrc Vsrc_gcd_vss.loc -voltage_file $voltage_file -net VSS \
   -enable_em -em_outfile $em_file
 

src/psm/test/gcd_sky130_vdd.py

@@ -11,4 +11,4 @@
 design.readDef("sky130hd_data/gcd_sky130hd_floorplan.def")
 design.evalTclString("read_sdc sky130hd_data/gcd_sky130hd_floorplan.sdc")
 
-pdnsim_aux.check_power_grid(design, net="VDD")
+pdnsim_aux.check_power_grid(design, net="VDD", require_bterm=False)

src/psm/test/gcd_sky130_vdd.tcl

@@ -5,4 +5,4 @@ read_def sky130hd_data/gcd_sky130hd_floorplan.def
 read_liberty sky130hd/sky130_fd_sc_hd__tt_025C_1v80.lib
 read_sdc sky130hd_data/gcd_sky130hd_floorplan.sdc
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals

src/psm/test/gcd_test_assign_power.tcl

@@ -10,5 +10,5 @@ set voltage_file [make_result_file gcd_test_vdd-voltage.rpt]
 set_pdnsim_inst_power -inst _440_ -power 1e-5
 set_pdnsim_inst_power -inst _829_ -power 1e-5
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals
 analyze_power_grid -vsrc Vsrc_gcd_vdd.loc -net VDD

src/psm/test/gcd_test_vdd.py

@@ -11,7 +11,7 @@
 design.evalTclString("read_sdc Nangate45_data/gcd.sdc")
 
 voltage_file = helpers.make_result_file("gcd_test_vdd-voltage.rpt")
-pdnsim_aux.check_power_grid(design, net="VDD")
+pdnsim_aux.check_power_grid(design, net="VDD", require_bterm=False)
 
 pdnsim_aux.analyze_power_grid(
     design, vsrc="Vsrc_gcd_vdd.loc", net="VDD", outfile=voltage_file

src/psm/test/gcd_test_vdd.tcl

@@ -7,7 +7,7 @@ read_sdc Nangate45_data/gcd.sdc
 
 set voltage_file [make_result_file gcd_test_vdd-voltage.rpt]
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals
 analyze_power_grid -vsrc Vsrc_gcd_vdd.loc -voltage_file $voltage_file -net VDD
 
 diff_files $voltage_file gcd_test_vdd-voltage.rptok

src/psm/test/pdnsim_aux.py

@@ -81,15 +81,17 @@ def analyze_power_grid(
     )
 
 
-def check_power_grid(design, *, net=None, error_file=None):
+def check_power_grid(design, *, net=None, error_file=None, require_bterm=True):
     pdnsim = design.getPDNSim()
     if not net:
         utl.error(utl.PSM, 157, "Argument 'net' not specified to check_power_grid.")
 
     if not error_file:
         error_file = ""
 
-    res = pdnsim.checkConnectivity(design.getBlock().findNet(net), False, error_file)
+    res = pdnsim.checkConnectivity(
+        design.getBlock().findNet(net), False, error_file, require_bterm
+    )
     if res == 0:
         utl.error(utl.PSM, 169, "Check connectivity failed.")
     return res

src/psm/test/switch_top_grid.tcl

@@ -4,7 +4,7 @@ read_def Nangate45_data/aes.def
 read_liberty Nangate45/Nangate45_typ.lib
 read_sdc Nangate45_data/aes.sdc
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals
 analyze_power_grid -net VDD -source_type BUMPS
 analyze_power_grid -net VDD -source_type FULL
 analyze_power_grid -net VDD -source_type STRAPS

src/psm/test/top_grid_settings.tcl

@@ -4,7 +4,7 @@ read_def Nangate45_data/aes.def
 read_liberty Nangate45/Nangate45_typ.lib
 read_sdc Nangate45_data/aes.sdc
 
-check_power_grid -net VDD
+check_power_grid -net VDD -dont_require_terminals
 set_pdnsim_source_settings -bump_dx 45 -bump_dy 45 -bump_size 25 -bump_interval 2
 analyze_power_grid -net VDD -source_type BUMPS
 set_pdnsim_source_settings -bump_dx 65 -bump_dy 65 -bump_size 25 -bump_interval 4