Improved placement of refresh commands.

DRAMSys/library/src/controller/BankMachine.cpp

@@ -44,7 +44,7 @@ BankMachine::BankMachine(SchedulerIF *scheduler, CheckerIF *checker, Bank bank)
 
 std::pair<Command, tlm_generic_payload *> BankMachine::getNextCommand()
 {
-    if (sc_time_stamp() == timeToSchedule && !blocked)
+    if (sc_time_stamp() == timeToSchedule)
         return std::pair<Command, tlm_generic_payload *>(nextCommand, currentPayload);
     else
         return std::pair<Command, tlm_generic_payload *>(Command::NOP, nullptr);
@@ -67,10 +67,14 @@ void BankMachine::updateState(Command command)
         currentPayload = nullptr;
     }
     else if (command == Command::PDEA || command == Command::PDEP || command == Command::SREFEN)
-        blocked = true;
-    else if (command == Command::REFA || command == Command::REFB
-             || command == Command::PDXA || command == Command::PDXP)
+        sleeping = true;
+    else if (command == Command::REFA || command == Command::REFB)
+    {
+        sleeping = false;
         blocked = false;
+    }
+    else if (command == Command::PDXA || command == Command::PDXP)
+        sleeping = false;
 }
 
 void BankMachine::block()
@@ -114,17 +118,19 @@ BankMachineOpen::BankMachineOpen(SchedulerIF *scheduler, CheckerIF *checker, Ban
 sc_time BankMachineOpen::start()
 {
     timeToSchedule = sc_max_time();
+    sc_time delay = sc_max_time() - sc_time_stamp();
 
-    if (blocked)
-        return sc_max_time() - sc_time_stamp();
-    else if (currentPayload == nullptr)
+    if (currentPayload == nullptr)
     {
         currentPayload = scheduler->getNextRequest(this);
         if (currentPayload == nullptr)
-            return sc_max_time() - sc_time_stamp();
+            return delay;
     }
-    sc_time delay;
-    if (currentState == BmState::Precharged) // row miss
+
+    if (sleeping)
+        return delay;
+
+    if (currentState == BmState::Precharged && !blocked) // row miss
     {
         delay = checker->delayToSatisfyConstraints(Command::ACT, rank, bankgroup, bank);
         nextCommand = Command::ACT;
@@ -152,6 +158,7 @@ sc_time BankMachineOpen::start()
             nextCommand = Command::PRE;
         }
     }
+
     timeToSchedule = sc_time_stamp() + delay;
     return delay;
 }
@@ -162,17 +169,19 @@ BankMachineClosed::BankMachineClosed(SchedulerIF *scheduler, CheckerIF *checker,
 sc_time BankMachineClosed::start()
 {
     timeToSchedule = sc_max_time();
+    sc_time delay = sc_max_time() - sc_time_stamp();
 
-    if (blocked)
-        return sc_max_time() - sc_time_stamp();
-    else if (currentPayload == nullptr)
+    if (currentPayload == nullptr)
     {
         currentPayload = scheduler->getNextRequest(this);
         if (currentPayload == nullptr)
-            return sc_max_time() - sc_time_stamp();
+            return delay;
     }
-    sc_time delay;
-    if (currentState == BmState::Precharged) // row miss
+
+    if (sleeping)
+        return delay;
+
+    if (currentState == BmState::Precharged && !blocked) // row miss
     {
         delay = checker->delayToSatisfyConstraints(Command::ACT, rank, bankgroup, bank);
         nextCommand = Command::ACT;
@@ -210,17 +219,19 @@ BankMachineOpenAdaptive::BankMachineOpenAdaptive(SchedulerIF *scheduler, Checker
 sc_time BankMachineOpenAdaptive::start()
 {
     timeToSchedule = sc_max_time();
+    sc_time delay = sc_max_time() - sc_time_stamp();
 
-    if (blocked)
-        return sc_max_time() - sc_time_stamp();
-    else if (currentPayload == nullptr)
+    if (currentPayload == nullptr)
     {
         currentPayload = scheduler->getNextRequest(this);
         if (currentPayload == nullptr)
-            return sc_max_time() - sc_time_stamp();
+            return delay;
     }
-    sc_time delay;
-    if (currentState == BmState::Precharged) // row miss
+
+    if (sleeping)
+        return delay;
+
+    if (currentState == BmState::Precharged && !blocked) // row miss
     {
         delay = checker->delayToSatisfyConstraints(Command::ACT, rank, bankgroup, bank);
         nextCommand = Command::ACT;
@@ -276,17 +287,19 @@ BankMachineClosedAdaptive::BankMachineClosedAdaptive(SchedulerIF *scheduler, Che
 sc_time BankMachineClosedAdaptive::start()
 {
     timeToSchedule = sc_max_time();
+    sc_time delay = sc_max_time() - sc_time_stamp();
 
-    if (blocked)
-        return sc_max_time() - sc_time_stamp();
-    else if (currentPayload == nullptr)
+    if (currentPayload == nullptr)
     {
         currentPayload = scheduler->getNextRequest(this);
         if (currentPayload == nullptr)
-            return sc_max_time() - sc_time_stamp();
+            return delay;
     }
-    sc_time delay;
-    if (currentState == BmState::Precharged) // row miss
+
+    if (sleeping)
+        return delay;
+
+    if (currentState == BmState::Precharged && !blocked) // row miss
     {
         delay = checker->delayToSatisfyConstraints(Command::ACT, rank, bankgroup, bank);
         nextCommand = Command::ACT;

DRAMSys/library/src/controller/BankMachine.h

@@ -84,6 +84,7 @@ protected:
     BankGroup bankgroup = BankGroup(0);
     Bank bank;
     bool blocked = false;
+    bool sleeping = false;
 };
 
 class BankMachineOpen final : public BankMachine

DRAMSys/library/src/controller/refresh/RefreshManager.cpp

@@ -90,7 +90,7 @@ sc_time RefreshManager::start()
         if (state == RmState::Regular)
         {
             bool forcedRefresh = (flexibilityCounter == maxPostponed);
-            if (!forcedRefresh && !controllerIdle)
+            if (!forcedRefresh && !controllerIdle) // no forced refresh & controller is busy -> postpone
             {
                 flexibilityCounter++;
                 timeForNextTrigger += memSpec->getRefreshIntervalAB();
@@ -98,6 +98,12 @@ sc_time RefreshManager::start()
             }
             else
             {
+                if (forcedRefresh)
+                {
+                    for (auto it : bankMachines)
+                        it->block();
+                }
+
                 if (activatedBanks > 0)
                     nextCommand = Command::PREA;
                 else