The DRAM controller is a single-channel memory controller capturing the most important timing constraints associated with a contemporary DRAM. More...

#include <dram_ctrl.hh>

Inheritance diagram for DRAMCtrl:

Classes
class	Bank
	A basic class to track the bank state, i.e. More...

class	BurstHelper
	A burst helper helps organize and manage a packet that is larger than the DRAM burst size. More...

struct	Command
	Simple structure to hold the values needed to keep track of commands for DRAMPower. More...

class	DRAMPacket
	A DRAM packet stores packets along with the timestamp of when the packet entered the queue, and also the decoded address. More...

struct	DRAMStats
	All statistics that the model needs to capture. More...

class	MemoryPort

class	Rank
	Rank class includes a vector of banks. More...

struct	RankStats

Public Member Functions
	DRAMCtrl (const DRAMCtrlParams *p)

DrainState	drain () override
	Notify an object that it needs to drain its state. More...

Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID) override
	Get a port with a given name and index. More...

virtual void	init () override
	init() is called after all C++ SimObjects have been created and all ports are connected. More...

virtual void	startup () override
	startup() is the final initialization call before simulation. More...

virtual void	drainResume () override
	Resume execution after a successful drain. More...

bool	allRanksDrained () const
	Return true once refresh is complete for all ranks and there are no additional commands enqueued. More...

Public Member Functions inherited from QoS::MemCtrl
	MemCtrl (const QoSMemCtrlParams *)
	QoS Memory base class. More...

virtual	~MemCtrl ()

void	init () override
	Initializes this object. More...

BusState	getBusState () const
	Gets the current bus state. More...

BusState	getBusStateNext () const
	Gets the next bus state. More...

bool	hasMaster (MasterID m_id) const
	hasMaster returns true if the selected master(ID) has been registered in the memory controller, which happens if the memory controller has received at least a packet from that master. More...

uint64_t	getReadQueueSize (const uint8_t prio) const
	Gets a READ queue size. More...

uint64_t	getWriteQueueSize (const uint8_t prio) const
	Gets a WRITE queue size. More...

uint64_t	getTotalReadQueueSize () const
	Gets the total combined READ queues size. More...

uint64_t	getTotalWriteQueueSize () const
	Gets the total combined WRITE queues size. More...

Tick	getServiceTick (const uint8_t prio) const
	Gets the last service tick related to a QoS Priority. More...

uint8_t	numPriorities () const
	Gets the total number of priority levels in the QoS memory controller. More...

Public Member Functions inherited from AbstractMemory
	AbstractMemory (const Params *p)

virtual	~AbstractMemory ()

void	initState () override
	initState() is called on each SimObject when not restoring from a checkpoint. More...

bool	isNull () const
	See if this is a null memory that should never store data and always return zero. More...

void	setBackingStore (uint8_t *pmem_addr)
	Set the host memory backing store to be used by this memory controller. More...

const std::list< LockedAddr > &	getLockedAddrList () const
	Get the list of locked addresses to allow checkpointing. More...

void	addLockedAddr (LockedAddr addr)
	Add a locked address to allow for checkpointing. More...

System *	system () const
	read the system pointer Implemented for completeness with the setter More...

void	system (System *sys)
	Set the system pointer on this memory This can't be done via a python parameter because the system needs pointers to all the memories and the reverse would create a cycle in the object graph. More...

const Params *	params () const

AddrRange	getAddrRange () const
	Get the address range. More...

uint8_t *	toHostAddr (Addr addr) const
	Transform a gem5 address space address into its physical counterpart in the host address space. More...

uint64_t	size () const
	Get the memory size. More...

Addr	start () const
	Get the start address. More...

bool	isConfReported () const
	Should this memory be passed to the kernel and part of the OS physical memory layout. More...

bool	isInAddrMap () const
	Some memories are used as shadow memories or should for other reasons not be part of the global address map. More...

bool	isKvmMap () const
	When shadow memories are in use, KVM may want to make one or the other, but cannot map both into the guest address space. More...

void	access (PacketPtr pkt)
	Perform an untimed memory access and update all the state (e.g. More...

void	functionalAccess (PacketPtr pkt)
	Perform an untimed memory read or write without changing anything but the memory itself. More...

Public Member Functions inherited from ClockedObject
	ClockedObject (const ClockedObjectParams *p)

const Params *	params () const

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. More...

Public Member Functions inherited from SimObject
virtual	~SimObject ()

virtual const std::string	name () const

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint. More...

virtual void	regProbePoints ()
	Register probe points for this object. More...

virtual void	regProbeListeners ()
	Register probe listeners for this object. More...

ProbeManager *	getProbeManager ()
	Get the probe manager for this object. More...

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining. More...

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes. More...

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers. More...

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. More...

const Params *	params () const

	SimObject (const Params *_params)

Public Member Functions inherited from EventManager
EventQueue *	eventQueue () const

void	schedule (Event &event, Tick when)

void	deschedule (Event &event)

void	reschedule (Event &event, Tick when, bool always=false)

void	schedule (Event *event, Tick when)

void	deschedule (Event *event)

void	reschedule (Event *event, Tick when, bool always=false)

void	wakeupEventQueue (Tick when=(Tick) -1)

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

Public Member Functions inherited from Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section. More...

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object. More...

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Public Member Functions inherited from Drainable
DrainState	drainState () const
	Return the current drain state of an object. More...

virtual void	notifyFork ()
	Notify a child process of a fork. More...

Public Member Functions inherited from Stats::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group. More...

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters. More...

virtual void	resetStats ()
	Callback to reset stats. More...

virtual void	preDumpStats ()
	Callback before stats are dumped. More...

void	addStat (Stats::Info *info)
	Register a stat with this group. More...

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object. More...

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object. More...

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block. More...

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group. More...

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from Clocked
void	updateClockPeriod ()
	Update the tick to the current tick. More...

Tick	clockEdge (Cycles cycles=Cycles(0)) const
	Determine the tick when a cycle begins, by default the current one, but the argument also enables the caller to determine a future cycle. More...

Cycles	curCycle () const
	Determine the current cycle, corresponding to a tick aligned to a clock edge. More...

Tick	nextCycle () const
	Based on the clock of the object, determine the start tick of the first cycle that is at least one cycle in the future. More...

uint64_t	frequency () const

Tick	clockPeriod () const

double	voltage () const

Cycles	ticksToCycles (Tick t) const

Tick	cyclesToTicks (Cycles c) const

Protected Member Functions
Tick	recvAtomic (PacketPtr pkt)

void	recvFunctional (PacketPtr pkt)

bool	recvTimingReq (PacketPtr pkt)

Protected Member Functions inherited from QoS::MemCtrl
void	addMaster (const MasterID m_id)
	Initializes dynamically counters and statistics for a given Master. More...

void	logRequest (BusState dir, MasterID m_id, uint8_t qos, Addr addr, uint64_t entries)
	Called upon receiving a request or updates statistics and updates queues status. More...

void	logResponse (BusState dir, MasterID m_id, uint8_t qos, Addr addr, uint64_t entries, double delay)
	Called upon receiving a response, updates statistics and updates queues status. More...

template<typename Queues >
uint8_t	qosSchedule (std::initializer_list< Queues *> queues_ptr, uint64_t queue_entry_size, const PacketPtr pkt)
	Assign priority to a packet by executing the configured QoS policy. More...

uint8_t	schedule (MasterID m_id, uint64_t data)

uint8_t	schedule (const PacketPtr pkt)

BusState	selectNextBusState ()
	Returns next bus direction (READ or WRITE) based on configured policy. More...

void	setCurrentBusState ()
	Set current bus direction (READ or WRITE) from next selected one. More...

void	recordTurnaroundStats ()
	Record statistics on turnarounds based on busStateNext and busState values. More...

template<typename Queues >
void	escalate (std::initializer_list< Queues *> queues, uint64_t queue_entry_size, MasterID m_id, uint8_t tgt_prio)
	Escalates/demotes priority of all packets belonging to the passed master to given priority value. More...

template<typename Queues >
void	escalateQueues (Queues &queues, uint64_t queue_entry_size, MasterID m_id, uint8_t curr_prio, uint8_t tgt_prio)
	Escalates/demotes priority of all packets belonging to the passed master to given priority value in a specified cluster of queues (e.g. More...

Protected Member Functions inherited from AbstractMemory
bool	checkLockedAddrList (PacketPtr pkt)

void	trackLoadLocked (PacketPtr pkt)

bool	writeOK (PacketPtr pkt)

Protected Member Functions inherited from Drainable
	Drainable ()

virtual	~Drainable ()

void	signalDrainDone () const
	Signal that an object is drained. More...

Protected Member Functions inherited from Clocked
	Clocked (ClockDomain &clk_domain)
	Create a clocked object and set the clock domain based on the parameters. More...

	Clocked (Clocked &)=delete

Clocked &	operator= (Clocked &)=delete

virtual	~Clocked ()
	Virtual destructor due to inheritance. More...

void	resetClock () const
	Reset the object's clock using the current global tick value. More...

virtual void	clockPeriodUpdated ()
	A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed. More...

Private Types
enum	PowerState { PWR_IDLE = 0, PWR_REF, PWR_SREF, PWR_PRE_PDN, PWR_ACT, PWR_ACT_PDN }
	The power state captures the different operational states of the DRAM and interacts with the bus read/write state machine, and the refresh state machine. More...

enum	RefreshState { REF_IDLE = 0, REF_DRAIN, REF_PD_EXIT, REF_SREF_EXIT, REF_PRE, REF_START, REF_RUN }
	The refresh state is used to control the progress of the refresh scheduling. More...

typedef std::deque< DRAMPacket * >	DRAMPacketQueue

Private Member Functions
void	processNextReqEvent ()
	Bunch of things requires to setup "events" in gem5 When event "respondEvent" occurs for example, the method processRespondEvent is called; no parameters are allowed in these methods. More...

void	processRespondEvent ()

bool	readQueueFull (unsigned int pktCount) const
	Check if the read queue has room for more entries. More...

bool	writeQueueFull (unsigned int pktCount) const
	Check if the write queue has room for more entries. More...

void	addToReadQueue (PacketPtr pkt, unsigned int pktCount)
	When a new read comes in, first check if the write q has a pending request to the same address. If not, decode the address to populate rank/bank/row, create one or mutliple "dram_pkt", and push them to the back of the read queue. More...

void	addToWriteQueue (PacketPtr pkt, unsigned int pktCount)
	Decode the incoming pkt, create a dram_pkt and push to the back of the write queue. More...

void	doDRAMAccess (DRAMPacket *dram_pkt)
	Actually do the DRAM access - figure out the latency it will take to service the req based on bank state, channel state etc and then update those states to account for this request. Based on this, update the packet's "readyTime" and move it to the response q from where it will eventually go back to the outside world. More...

void	accessAndRespond (PacketPtr pkt, Tick static_latency)
	When a packet reaches its "readyTime" in the response Q, use the "access()" method in AbstractMemory to actually create the response packet, and send it back to the outside world requestor. More...

DRAMPacket *	decodeAddr (const PacketPtr pkt, Addr dramPktAddr, unsigned int size, bool isRead) const
	Address decoder to figure out physical mapping onto ranks, banks, and rows. More...

Addr	getCtrlAddr (Addr addr)
	Get an address in a dense range which starts from 0. More...

DRAMPacketQueue::iterator	chooseNext (DRAMPacketQueue &queue, Tick extra_col_delay)
	The memory schduler/arbiter - picks which request needs to go next, based on the specified policy such as FCFS or FR-FCFS and moves it to the head of the queue. More...

DRAMPacketQueue::iterator	chooseNextFRFCFS (DRAMPacketQueue &queue, Tick extra_col_delay)
	For FR-FCFS policy reorder the read/write queue depending on row buffer hits and earliest bursts available in DRAM. More...

std::pair< std::vector< uint32_t >, bool >	minBankPrep (const DRAMPacketQueue &queue, Tick min_col_at) const
	Find which are the earliest banks ready to issue an activate for the enqueued requests. More...

void	pruneBurstTick ()
	Remove commands that have already issued from burstTicks. More...

Tick	getBurstWindow (Tick cmd_tick)
	Calculate burst window aligned tick. More...

Tick	verifySingleCmd (Tick cmd_tick)
	Check for command bus contention for single cycle command. More...

Tick	verifyMultiCmd (Tick cmd_tick, Tick max_multi_cmd_split=0)
	Check for command bus contention for multi-cycle (2 currently) command. More...

void	activateBank (Rank &rank_ref, Bank &bank_ref, Tick act_tick, uint32_t row)
	Keep track of when row activations happen, in order to enforce the maximum number of activations in the activation window. More...

void	prechargeBank (Rank &rank_ref, Bank &bank_ref, Tick pre_tick, bool auto_or_preall=false, bool trace=true)
	Precharge a given bank and also update when the precharge is done. More...

void	printQs () const
	Used for debugging to observe the contents of the queues. More...

Addr	burstAlign (Addr addr) const
	Burst-align an address. More...

void	updatePowerStats (Rank &rank_ref)
	This function increments the energy when called. More...

Static Private Member Functions
static bool	sortTime (const Command &cmd, const Command &cmd_next)
	Function for sorting Command structures based on timeStamp. More...

Private Attributes
MemoryPort	port
	Our incoming port, for a multi-ported controller add a crossbar in front of it. More...

bool	isTimingMode
	Remember if the memory system is in timing mode. More...

bool	retryRdReq
	Remember if we have to retry a request when available. More...

bool	retryWrReq

EventFunctionWrapper	nextReqEvent

EventFunctionWrapper	respondEvent

std::vector< DRAMPacketQueue >	readQueue
	The controller's main read and write queues, with support for QoS reordering. More...

std::vector< DRAMPacketQueue >	writeQueue

std::unordered_set< Addr >	isInWriteQueue
	To avoid iterating over the write queue to check for overlapping transactions, maintain a set of burst addresses that are currently queued. More...

std::deque< DRAMPacket * >	respQueue
	Response queue where read packets wait after we're done working with them, but it's not time to send the response yet. More...

std::unordered_multiset< Tick >	burstTicks
	Holds count of commands issued in burst window starting at defined Tick. More...

std::vector< Rank * >	ranks
	Vector of ranks. More...

const uint32_t	deviceSize
	The following are basic design parameters of the memory controller, and are initialized based on parameter values. More...

const uint32_t	deviceBusWidth

const uint32_t	burstLength

const uint32_t	deviceRowBufferSize

const uint32_t	devicesPerRank

const uint32_t	burstSize

const uint32_t	rowBufferSize

const uint32_t	columnsPerRowBuffer

const uint32_t	columnsPerStripe

const uint32_t	ranksPerChannel

const uint32_t	bankGroupsPerRank

const bool	bankGroupArch

const uint32_t	banksPerRank

uint32_t	rowsPerBank

const uint32_t	readBufferSize

const uint32_t	writeBufferSize

const uint32_t	writeHighThreshold

const uint32_t	writeLowThreshold

const uint32_t	minWritesPerSwitch

uint32_t	writesThisTime

uint32_t	readsThisTime

const Tick M5_CLASS_VAR_USED	tCK
	Basic memory timing parameters initialized based on parameter values. More...

const Tick	tRTW

const Tick	tCS

const Tick	tBURST

const Tick	tBURST_MIN

const Tick	tCCD_L_WR

const Tick	tCCD_L

const Tick	tRCD

const Tick	tCL

const Tick	tRP

const Tick	tRAS

const Tick	tWR

const Tick	tRTP

const Tick	tRFC

const Tick	tREFI

const Tick	tRRD

const Tick	tRRD_L

const Tick	tPPD

const Tick	tAAD

const Tick	tXAW

const Tick	tXP

const Tick	tXS

const Tick	clkResyncDelay

unsigned int	maxCommandsPerBurst

const bool	dataClockSync

const uint8_t	twoCycleActivate

const uint32_t	activationLimit

const Tick	rankToRankDly

const Tick	wrToRdDly

const Tick	rdToWrDly

const Tick	wrToRdDlySameBG

const Tick	rdToWrDlySameBG

const bool	burstInterleave

const Tick	burstDataCycles

Enums::MemSched	memSchedPolicy
	Memory controller configuration initialized based on parameter values. More...

Enums::AddrMap	addrMapping

Enums::PageManage	pageMgmt

const uint32_t	maxAccessesPerRow
	Max column accesses (read and write) per row, before forcefully closing it. More...

const Tick	frontendLatency
	Pipeline latency of the controller frontend. More...

const Tick	backendLatency
	Pipeline latency of the backend and PHY. More...

Tick	nextBurstAt
	Till when must we wait before issuing next RD/WR burst? More...

Tick	prevArrival

Tick	nextReqTime
	The soonest you have to start thinking about the next request is the longest access time that can occur before nextBurstAt. More...

DRAMStats	stats

uint8_t	activeRank

uint64_t	timeStampOffset

Tick	lastStatsResetTick
	The time when stats were last reset used to calculate average power. More...

bool	enableDRAMPowerdown
	Enable or disable DRAM powerdown states. More...

std::unique_ptr< Packet >	pendingDelete
	Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call. More...

Additional Inherited Members
Public Types inherited from QoS::MemCtrl
enum	BusState { READ, WRITE }
	Bus Direction. More...

Public Types inherited from AbstractMemory
typedef AbstractMemoryParams	Params

Public Types inherited from ClockedObject
typedef ClockedObjectParams	Params
	Parameters of ClockedObject. More...

Public Types inherited from SimObject
typedef SimObjectParams	Params

Static Public Member Functions inherited from SimObject
static void	serializeAll (CheckpointOut &cp)
	Serialize all SimObjects in the system. More...

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it. More...

Static Public Member Functions inherited from Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section. More...

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Public Attributes inherited from ClockedObject
PowerState *	powerState

Protected Attributes inherited from QoS::MemCtrl
const std::unique_ptr< Policy >	policy
	QoS Policy, assigns QoS priority to the incoming packets. More...

const std::unique_ptr< TurnaroundPolicy >	turnPolicy
	QoS Bus Turnaround Policy: selects the bus direction (READ/WRITE) More...

const std::unique_ptr< QueuePolicy >	queuePolicy
	QoS Queue Policy: selects packet among same-priority queue. More...

const uint8_t	_numPriorities
	Number of configured QoS priorities. More...

const bool	qosPriorityEscalation
	Enables QoS priority escalation. More...

const bool	qosSyncroScheduler
	Enables QoS synchronized scheduling invokes the QoS scheduler on all masters, at every packet arrival. More...

std::unordered_map< MasterID, const std::string >	masters
	Hash of master ID - master name. More...

std::unordered_map< MasterID, std::vector< uint64_t > >	packetPriorities
	Hash of masters - number of packets queued per priority. More...

std::unordered_map< MasterID, std::unordered_map< uint64_t, std::deque< uint64_t > > >	requestTimes
	Hash of masters - address of request - queue of times of request. More...

std::vector< Tick >	serviceTick
	Vector of QoS priorities/last service time. More...

std::vector< uint64_t >	readQueueSizes
	Read request packets queue length in #packets, per QoS priority. More...

std::vector< uint64_t >	writeQueueSizes
	Write request packets queue length in #packets, per QoS priority. More...

uint64_t	totalReadQueueSize
	Total read request packets queue length in #packets. More...

uint64_t	totalWriteQueueSize
	Total write request packets queue length in #packets. More...

BusState	busState
	Bus state used to control the read/write switching and drive the scheduling of the next request. More...

BusState	busStateNext
	bus state for next request event triggered More...

QoS::MemCtrl::MemCtrlStats	stats

Protected Attributes inherited from AbstractMemory
AddrRange	range

uint8_t *	pmemAddr

MemBackdoor	backdoor

const bool	confTableReported

const bool	inAddrMap

const bool	kvmMap

std::list< LockedAddr >	lockedAddrList

System *	_system
	Pointer to the System object. More...

AbstractMemory::MemStats	stats

Protected Attributes inherited from SimObject
const SimObjectParams *	_params
	Cached copy of the object parameters. More...

Protected Attributes inherited from EventManager
EventQueue *	eventq
	A pointer to this object's event queue. More...

Detailed Description

The DRAM controller is a single-channel memory controller capturing the most important timing constraints associated with a contemporary DRAM.

For multi-channel memory systems, the controller is combined with a crossbar model, with the channel address interleaving taking part in the crossbar.

As a basic design principle, this controller model is not cycle callable, but instead uses events to: 1) decide when new decisions can be made, 2) when resources become available, 3) when things are to be considered done, and 4) when to send things back. Through these simple principles, the model delivers high performance, and lots of flexibility, allowing users to evaluate the system impact of a wide range of memory technologies, such as DDR3/4, LPDDR2/3/4, WideIO1/2, HBM and HMC.

For more details, please see Hansson et al, "Simulating DRAM controllers for future system architecture exploration", Proc. ISPASS, 2014. If you use this model as part of your research please cite the paper.

The low-power functionality implements a staggered powerdown similar to that described in "Optimized Active and Power-Down Mode Refresh Control in 3D-DRAMs" by Jung et al, VLSI-SoC, 2014.

Definition at line 90 of file dram_ctrl.hh.

Member Typedef Documentation

◆ DRAMPacketQueue

typedef std::deque<DRAMPacket*> DRAMCtrl::DRAMPacketQueue

private

Definition at line 721 of file dram_ctrl.hh.

Member Enumeration Documentation

◆ PowerState

enum DRAMCtrl::PowerState

private

The power state captures the different operational states of the DRAM and interacts with the bus read/write state machine, and the refresh state machine.

PWR_IDLE : The idle state in which all banks are closed From here can transition to: PWR_REF, PWR_ACT, PWR_PRE_PDN

PWR_REF : Auto-refresh state. Will transition when refresh is complete based on power state prior to PWR_REF From here can transition to: PWR_IDLE, PWR_PRE_PDN, PWR_SREF

PWR_SREF : Self-refresh state. Entered after refresh if previous state was PWR_PRE_PDN From here can transition to: PWR_IDLE

PWR_PRE_PDN : Precharge power down state From here can transition to: PWR_REF, PWR_IDLE

PWR_ACT : Activate state in which one or more banks are open From here can transition to: PWR_IDLE, PWR_ACT_PDN

PWR_ACT_PDN : Activate power down state From here can transition to: PWR_ACT

Enumerator
PWR_IDLE
PWR_REF
PWR_SREF
PWR_PRE_PDN
PWR_ACT
PWR_ACT_PDN

Definition at line 216 of file dram_ctrl.hh.

◆ RefreshState

enum DRAMCtrl::RefreshState

private

The refresh state is used to control the progress of the refresh scheduling.

When normal operation is in progress the refresh state is idle. Once tREFI has elasped, a refresh event is triggered to start the following STM transitions which are used to issue a refresh and return back to normal operation

REF_IDLE : IDLE state used during normal operation From here can transition to: REF_DRAIN

REF_SREF_EXIT : Exiting a self-refresh; refresh event scheduled after self-refresh exit completes From here can transition to: REF_DRAIN

REF_DRAIN : Drain state in which on going accesses complete. From here can transition to: REF_PD_EXIT

REF_PD_EXIT : Evaluate pwrState and issue wakeup if needed Next state dependent on whether banks are open From here can transition to: REF_PRE, REF_START

REF_PRE : Close (precharge) all open banks From here can transition to: REF_START

REF_START : Issue refresh command and update DRAMPower stats From here can transition to: REF_RUN

REF_RUN : Refresh running, waiting for tRFC to expire From here can transition to: REF_IDLE, REF_SREF_EXIT

Enumerator
REF_IDLE
REF_DRAIN
REF_PD_EXIT
REF_SREF_EXIT
REF_PRE
REF_START
REF_RUN

Definition at line 255 of file dram_ctrl.hh.

Constructor & Destructor Documentation

◆ DRAMCtrl()

DRAMCtrl::DRAMCtrl ( const DRAMCtrlParams * p )

Definition at line 55 of file dram_ctrl.cc.

References activationLimit, activeRank, addrMapping, backendLatency, bankGroupArch, bankGroupsPerRank, banksPerRank, burstDataCycles, burstInterleave, burstLength, burstSize, ceilLog2(), clkResyncDelay, columnsPerRowBuffer, columnsPerStripe, dataClockSync, deviceBusWidth, deviceRowBufferSize, deviceSize, devicesPerRank, DPRINTF, enableDRAMPowerdown, fatal, fatal_if, frontendLatency, AddrRange::granularity(), ArmISA::i, AddrRange::interleaved(), isPowerOf2(), lastStatsResetTick, maxAccessesPerRow, maxCommandsPerBurst, memSchedPolicy, minWritesPerSwitch, SimObject::name(), nextBurstAt, nextReqTime, MipsISA::p, pageMgmt, prevArrival, processNextReqEvent(), processRespondEvent(), AbstractMemory::range, ranks, ranksPerChannel, rankToRankDly, rdToWrDly, rdToWrDlySameBG, readBufferSize, readQueue, readsThisTime, respondEvent, rowBufferSize, rowsPerBank, AbstractMemory::size(), stats, tAAD, tBURST, tBURST_MIN, tCCD_L, tCCD_L_WR, tCK, tCL, tCS, timeStampOffset, tPPD, tRAS, tRCD, tREFI, tRFC, tRP, tRRD, tRRD_L, tRTP, tRTW, twoCycleActivate, tWR, tXAW, tXP, tXS, ULL, warn, writeBufferSize, writeHighThreshold, writeLowThreshold, writeQueue, writesThisTime, wrToRdDly, and wrToRdDlySameBG.

Referenced by DRAMCtrl::MemoryPort::recvTimingReq(), and sortTime().

Member Function Documentation

◆ accessAndRespond()

void DRAMCtrl::accessAndRespond	(	PacketPtr	pkt,
		Tick	static_latency
	)

private

When a packet reaches its "readyTime" in the response Q, use the "access()" method in AbstractMemory to actually create the response packet, and send it back to the outside world requestor.

Parameters

pkt	The packet from the outside world
static_latency	Static latency to add before sending the packet

Definition at line 897 of file dram_ctrl.cc.

References AbstractMemory::access(), curTick(), DPRINTF, Packet::getAddr(), Packet::headerDelay, Packet::isResponse(), Packet::needsResponse(), Packet::payloadDelay, pendingDelete, port, and QueuedSlavePort::schedTimingResp().

Referenced by addToReadQueue(), addToWriteQueue(), and processRespondEvent().

◆ activateBank()

void DRAMCtrl::activateBank	(	Rank &	rank_ref,
		Bank &	bank_ref,
		Tick	act_tick,
		uint32_t	row
	)

private

Keep track of when row activations happen, in order to enforce the maximum number of activations in the activation window.

The method updates the time that the banks become available based on the current limits.

Parameters

rank_ref	Reference to the rank
bank_ref	Reference to the bank
act_tick	Time when the activation takes place
row	Index of the row

Definition at line 1040 of file dram_ctrl.cc.

References DRAMCtrl::Rank::activateEvent, activationLimit, DRAMCtrl::Rank::actTicks, DRAMCtrl::Bank::bank, DRAMCtrl::Bank::bankgr, bankGroupArch, DRAMCtrl::Rank::banks, banksPerRank, DRAMCtrl::Bank::bytesAccessed, DRAMCtrl::Rank::cmdList, divCeil(), DPRINTF, ArmISA::i, ArmISA::j, DRAMCtrl::Bank::NO_ROW, DRAMCtrl::Rank::numBanksActive, DRAMCtrl::Bank::openRow, panic, DRAMCtrl::Bank::preAllowedAt, DRAMCtrl::Rank::rank, ranks, DRAMCtrl::Bank::rdAllowedAt, EventManager::reschedule(), DRAMCtrl::Bank::rowAccesses, QoS::MemCtrl::schedule(), Event::scheduled(), tAAD, tCK, timeStampOffset, tRAS, tRCD, tRRD, tRRD_L, twoCycleActivate, tXAW, verifyMultiCmd(), verifySingleCmd(), Event::when(), and DRAMCtrl::Bank::wrAllowedAt.

Referenced by doDRAMAccess(), and getCtrlAddr().

◆ addToReadQueue()

void DRAMCtrl::addToReadQueue	(	PacketPtr	pkt,
		unsigned int	pktCount
	)

private

When a new read comes in, first check if the write q has a pending request to the same address. If not, decode the address to populate rank/bank/row, create one or mutliple "dram_pkt", and push them to the back of the read queue.

\ If this is the only read request in the system, schedule an event to start servicing it.

Parameters

pkt	The request packet from the outside world
pktCount	The number of DRAM bursts the pkt translate to. If pkt size is larger then one full burst, then pktCount is greater than one.

Definition at line 382 of file dram_ctrl.cc.

References accessAndRespond(), addr, DRAMCtrl::DRAMPacket::addr, DRAMCtrl::DRAMStats::avgRdQLen, burstAlign(), DRAMCtrl::DRAMPacket::burstHelper, burstSize, DRAMCtrl::BurstHelper::burstsServiced, DRAMCtrl::DRAMStats::bytesReadWrQ, ceilLog2(), curTick(), decodeAddr(), DPRINTF, frontendLatency, Packet::getAddr(), getCtrlAddr(), Packet::getSize(), isInWriteQueue, Packet::isWrite(), QoS::MemCtrl::logRequest(), Packet::masterId(), DRAMCtrl::DRAMStats::masterReadAccesses, nextReqEvent, MipsISA::p, DRAMCtrl::DRAMPacket::qosValue(), Packet::qosValue(), DRAMCtrl::DRAMPacket::rankRef, DRAMCtrl::DRAMStats::rdQLenPdf, DRAMCtrl::DRAMStats::readBursts, DRAMCtrl::Rank::readEntries, DRAMCtrl::DRAMStats::readPktSize, readQueue, readQueueFull(), respQueue, QoS::MemCtrl::schedule(), Event::scheduled(), DRAMCtrl::DRAMStats::servicedByWrQ, AbstractMemory::size(), stats, QoS::MemCtrl::totalReadQueueSize, and writeQueue.

Referenced by recvTimingReq().

◆ addToWriteQueue()

void DRAMCtrl::addToWriteQueue	(	PacketPtr	pkt,
		unsigned int	pktCount
	)

private

Decode the incoming pkt, create a dram_pkt and push to the back of the write queue.

the write q length is more than the threshold specified by the user, ie the queue is beginning to get full, stop reads, and start draining writes.

Parameters

pkt	The request packet from the outside world
pktCount	The number of DRAM bursts the pkt translate to. If pkt size is larger then one full burst, then pktCount is greater than one.

Definition at line 489 of file dram_ctrl.cc.

References accessAndRespond(), addr, DRAMCtrl::DRAMPacket::addr, DRAMCtrl::DRAMStats::avgWrQLen, burstAlign(), burstSize, ceilLog2(), curTick(), decodeAddr(), DPRINTF, frontendLatency, Packet::getAddr(), getCtrlAddr(), Packet::getSize(), isInWriteQueue, Packet::isWrite(), QoS::MemCtrl::logRequest(), Packet::masterId(), DRAMCtrl::DRAMStats::masterWriteAccesses, DRAMCtrl::DRAMStats::mergedWrBursts, nextReqEvent, DRAMCtrl::DRAMPacket::qosValue(), Packet::qosValue(), DRAMCtrl::DRAMPacket::rankRef, QoS::MemCtrl::schedule(), Event::scheduled(), AbstractMemory::size(), stats, QoS::MemCtrl::totalWriteQueueSize, writeBufferSize, DRAMCtrl::DRAMStats::writeBursts, DRAMCtrl::Rank::writeEntries, DRAMCtrl::DRAMStats::writePktSize, writeQueue, and DRAMCtrl::DRAMStats::wrQLenPdf.

Referenced by recvTimingReq().

◆ allRanksDrained()

bool DRAMCtrl::allRanksDrained ( ) const

Return true once refresh is complete for all ranks and there are no additional commands enqueued.

(only evaluated when draining) This will ensure that all banks are closed, power state is IDLE, and power stats have been updated

Returns: true if all ranks have refreshed, with no commands enqueued

Definition at line 2929 of file dram_ctrl.cc.

References MipsISA::r, and ranks.

Referenced by drain(), processNextReqEvent(), processRespondEvent(), and sortTime().

◆ burstAlign()

Addr DRAMCtrl::burstAlign ( Addr addr ) const

inlineprivate

Burst-align an address.

Parameters

addr	The potentially unaligned address

Returns: An address aligned to a DRAM burst

Definition at line 951 of file dram_ctrl.hh.

References burstSize.

Referenced by addToReadQueue(), addToWriteQueue(), and processNextReqEvent().

◆ chooseNext()

DRAMCtrl::DRAMPacketQueue::iterator DRAMCtrl::chooseNext	(	DRAMPacketQueue &	queue,
		Tick	extra_col_delay
	)

private

The memory schduler/arbiter - picks which request needs to go next, based on the specified policy such as FCFS or FR-FCFS and moves it to the head of the queue.

Prioritizes accesses to the same rank as previous burst unless controller is switching command type.

Parameters

queue	Queued requests to consider
extra_col_delay	Any extra delay due to a read/write switch

Returns: an iterator to the selected packet, else queue.end()

Definition at line 752 of file dram_ctrl.cc.

References chooseNextFRFCFS(), DPRINTF, ArmISA::i, memSchedPolicy, panic, DRAMCtrl::DRAMPacket::rank, and ranks.

Referenced by getCtrlAddr(), and processNextReqEvent().

◆ chooseNextFRFCFS()

DRAMCtrl::DRAMPacketQueue::iterator DRAMCtrl::chooseNextFRFCFS	(	DRAMPacketQueue &	queue,
		Tick	extra_col_delay
	)

private

For FR-FCFS policy reorder the read/write queue depending on row buffer hits and earliest bursts available in DRAM.

Parameters

queue	Queued requests to consider
extra_col_delay	Any extra delay due to a read/write switch

Returns: an iterator to the selected packet, else queue.end()

Definition at line 787 of file dram_ctrl.cc.

References DRAMCtrl::Bank::bank, DRAMCtrl::DRAMPacket::bank, DRAMCtrl::DRAMPacket::bankRef, bits(), curTick(), DPRINTF, ArmISA::i, DRAMCtrl::Rank::inRefIdleState(), DRAMCtrl::DRAMPacket::isRead(), minBankPrep(), nextBurstAt, DRAMCtrl::Bank::openRow, DRAMCtrl::Rank::rank, DRAMCtrl::DRAMPacket::rank, DRAMCtrl::DRAMPacket::rankRef, ranksPerChannel, DRAMCtrl::Bank::rdAllowedAt, DRAMCtrl::DRAMPacket::row, and DRAMCtrl::Bank::wrAllowedAt.

Referenced by chooseNext(), and getCtrlAddr().

◆ decodeAddr()

DRAMCtrl::DRAMPacket * DRAMCtrl::decodeAddr	(	const PacketPtr	pkt,
		Addr	dramPktAddr,
		unsigned int	size,
		bool	isRead
	)		const

private

Address decoder to figure out physical mapping onto ranks, banks, and rows.

This function is called multiple times on the same system packet if the pakcet is larger than burst of the memory. The dramPktAddr is used for the offset within the packet.

Parameters

pkt	The packet from the outside world
dramPktAddr	The starting address of the DRAM packet
size	The size of the DRAM packet in bytes
isRead	Is the request for a read or a write to DRAM

Returns: A DRAMPacket pointer with the decoded information

Definition at line 306 of file dram_ctrl.cc.

References addr, addrMapping, banksPerRank, burstSize, columnsPerRowBuffer, columnsPerStripe, DPRINTF, DRAMCtrl::Bank::NO_ROW, panic, ranks, ranksPerChannel, and rowsPerBank.

Referenced by addToReadQueue(), and addToWriteQueue().

◆ doDRAMAccess()

void DRAMCtrl::doDRAMAccess ( DRAMPacket * dram_pkt )

private

Actually do the DRAM access - figure out the latency it will take to service the req based on bank state, channel state etc and then update those states to account for this request. Based on this, update the packet's "readyTime" and move it to the response q from where it will eventually go back to the outside world.

Parameters

pkt	The DRAM packet created from the outside world pkt

Definition at line 1212 of file dram_ctrl.cc.

Referenced by processNextReqEvent().

◆ drain()

DrainState DRAMCtrl::drain ( )

overridevirtual

Notify an object that it needs to drain its state.

If the object does not need further simulation to drain internal buffers, it returns DrainState::Drained and automatically switches to the Drained state. If the object needs more simulation, it returns DrainState::Draining and automatically enters the Draining state. Other return values are invalid.

Note: An object that has entered the Drained state can be disturbed by other objects in the system and consequently stop being drained. These perturbations are not visible in the drain state. The simulator therefore repeats the draining process until all objects return DrainState::Drained on the first call to drain().

Returns: DrainState::Drained if the object is drained at this point in time, DrainState::Draining if it needs further simulation.

Implements Drainable.

Definition at line 2895 of file dram_ctrl.cc.

References allRanksDrained(), curTick(), DPRINTF, Drained, Draining, nextReqEvent, PWR_SREF, MipsISA::r, ranks, respQueue, QoS::MemCtrl::schedule(), Event::scheduled(), QoS::MemCtrl::totalReadQueueSize, QoS::MemCtrl::totalWriteQueueSize, and tXS.

Referenced by sortTime().

◆ drainResume()

void DRAMCtrl::drainResume ( )

overridevirtual

Resume execution after a successful drain.

Reimplemented from Drainable.

Definition at line 2944 of file dram_ctrl.cc.

References isTimingMode, System::isTimingMode(), MipsISA::r, ranks, startup(), and AbstractMemory::system().

Referenced by sortTime().

◆ getBurstWindow()

Tick DRAMCtrl::getBurstWindow ( Tick cmd_tick )

private

Calculate burst window aligned tick.

Parameters

cmd_tick Initial tick of command

Returns: burst window aligned tick

Definition at line 947 of file dram_ctrl.cc.

References burstDataCycles.

Referenced by getCtrlAddr(), verifyMultiCmd(), and verifySingleCmd().

◆ getCtrlAddr()

Addr DRAMCtrl::getCtrlAddr ( Addr addr )

inlineprivate

Get an address in a dense range which starts from 0.

The input address is the physical address of the request in an address space that contains other SimObjects apart from this controller.

Parameters

addr	The intput address which should be in the addrRange

Returns: An address in the continues range [0, max)

Definition at line 827 of file dram_ctrl.hh.

References activateBank(), chooseNext(), chooseNextFRFCFS(), getBurstWindow(), AddrRange::getOffset(), minBankPrep(), prechargeBank(), printQs(), pruneBurstTick(), DRAMCtrl::MemoryPort::queue, AbstractMemory::range, verifyMultiCmd(), and verifySingleCmd().

Referenced by addToReadQueue(), and addToWriteQueue().

◆ getPort()

Port & DRAMCtrl::getPort	(	const std::string &	if_name,
		PortID	idx = `InvalidPortID`
	)

overridevirtual

Get a port with a given name and index.

This is used at binding time and returns a reference to a protocol-agnostic port.

Parameters

if_name	Port name
idx	Index in the case of a VectorPort

Returns: A reference to the given port

Reimplemented from SimObject.

Definition at line 2885 of file dram_ctrl.cc.

References SimObject::getPort(), and port.

Referenced by sortTime().

◆ init()

void DRAMCtrl::init ( )

overridevirtual

init() is called after all C++ SimObjects have been created and all ports are connected.

Initializations that are independent of unserialization but rely on a fully instantiated and connected SimObject graph should be done here.

Reimplemented from SimObject.

Definition at line 193 of file dram_ctrl.cc.

References addrMapping, columnsPerRowBuffer, columnsPerStripe, fatal, AddrRange::granularity(), Stats::init, AddrRange::interleaved(), Port::isConnected(), SimObject::name(), port, AbstractMemory::range, rowBufferSize, SlavePort::sendRangeChange(), and AbstractMemory::system().

Referenced by sortTime().

◆ minBankPrep()

pair< vector< uint32_t >, bool > DRAMCtrl::minBankPrep	(	const DRAMPacketQueue &	queue,
		Tick	min_col_at
	)		const

private

Find which are the earliest banks ready to issue an activate for the enqueued requests.

Assumes maximum of 32 banks per rank Also checks if the bank is already prepped.

Parameters

queue	Queued requests to consider
min_col_at	time of seamless burst command

Returns: One-hot encoded mask of bank indices; boolean indicating burst can issue seamlessly, with no gaps

Definition at line 1779 of file dram_ctrl.cc.

References banksPerRank, QoS::MemCtrl::busState, curTick(), MipsISA::fill, ArmISA::i, ArmISA::j, MaxTick, DRAMCtrl::Bank::NO_ROW, MipsISA::p, ranks, ranksPerChannel, QoS::MemCtrl::READ, replaceBits(), tRCD, and tRP.

Referenced by chooseNextFRFCFS(), and getCtrlAddr().

◆ prechargeBank()

void DRAMCtrl::prechargeBank	(	Rank &	rank_ref,
		Bank &	bank_ref,
		Tick	pre_tick,
		bool	auto_or_preall = `false`,
		bool	trace = `true`
	)

private

Precharge a given bank and also update when the precharge is done.

This will also deal with any stats related to the accesses to the open page.

Parameters

rank_ref	The rank to precharge
bank_ref	The bank to precharge
pre_tick	Time when the precharge takes place
auto_or_preall	Is this an auto-precharge or precharge all command
trace	Is this an auto precharge then do not add to trace

Definition at line 1149 of file dram_ctrl.cc.

References DRAMCtrl::Bank::actAllowedAt, DRAMCtrl::Bank::bank, DRAMCtrl::Rank::banks, banksPerRank, DRAMCtrl::Bank::bytesAccessed, DRAMCtrl::DRAMStats::bytesPerActivate, DRAMCtrl::Rank::cmdList, divCeil(), DPRINTF, ArmISA::i, DRAMCtrl::Bank::NO_ROW, DRAMCtrl::Rank::numBanksActive, DRAMCtrl::Bank::openRow, DRAMCtrl::Rank::outstandingEvents, DRAMCtrl::Bank::preAllowedAt, DRAMCtrl::Rank::prechargeEvent, DRAMCtrl::Rank::rank, EventManager::reschedule(), Stats::DistBase< Derived, Stor >::sample(), QoS::MemCtrl::schedule(), Event::scheduled(), stats, tCK, timeStampOffset, tPPD, tRP, verifySingleCmd(), and Event::when().

Referenced by doDRAMAccess(), and getCtrlAddr().

◆ printQs()

void DRAMCtrl::printQs ( ) const

private

Used for debugging to observe the contents of the queues.

Definition at line 563 of file dram_ctrl.cc.

References DPRINTF, readQueue, respQueue, and writeQueue.

Referenced by getCtrlAddr().

◆ processNextReqEvent()

void DRAMCtrl::processNextReqEvent ( )

private

Bunch of things requires to setup "events" in gem5 When event "respondEvent" occurs for example, the method processRespondEvent is called; no parameters are allowed in these methods.

Definition at line 1473 of file dram_ctrl.cc.

References allRanksDrained(), burstAlign(), burstSize, QoS::MemCtrl::busState, QoS::MemCtrl::busStateNext, chooseNext(), curTick(), doDRAMAccess(), DPRINTF, Draining, Drainable::drainState(), isInWriteQueue, QoS::MemCtrl::logResponse(), minWritesPerSwitch, nextReqEvent, nextReqTime, QoS::MemCtrl::numPriorities(), port, PWR_SREF, MipsISA::r, ranks, ranksPerChannel, DRAMCtrl::DRAMStats::rdPerTurnAround, QoS::MemCtrl::READ, readQueue, readsThisTime, QoS::MemCtrl::recordTurnaroundStats(), EventManager::reschedule(), respondEvent, respQueue, retryWrReq, Stats::DistBase< Derived, Stor >::sample(), QoS::MemCtrl::schedule(), Event::scheduled(), QoS::MemCtrl::selectNextBusState(), SlavePort::sendRetryReq(), Drainable::signalDrainDone(), stats, tCS, QoS::MemCtrl::totalReadQueueSize, QoS::MemCtrl::totalWriteQueueSize, tRTW, QoS::MemCtrl::turnPolicy, tXS, QoS::MemCtrl::WRITE, writeBufferSize, writeHighThreshold, writeLowThreshold, writeQueue, writesThisTime, and DRAMCtrl::DRAMStats::wrPerTurnAround.

Referenced by DRAMCtrl().

◆ processRespondEvent()

void DRAMCtrl::processRespondEvent ( )

private

Definition at line 652 of file dram_ctrl.cc.

References accessAndRespond(), DRAMCtrl::Rank::activateEvent, allRanksDrained(), backendLatency, DRAMCtrl::BurstHelper::burstCount, DRAMCtrl::DRAMPacket::burstHelper, DRAMCtrl::BurstHelper::burstsServiced, curTick(), DPRINTF, Draining, Drainable::drainState(), enableDRAMPowerdown, frontendLatency, DRAMCtrl::Rank::inRefIdleState(), DRAMCtrl::Rank::isQueueEmpty(), DRAMCtrl::Rank::outstandingEvents, DRAMCtrl::DRAMPacket::pkt, port, DRAMCtrl::Rank::powerDownSleep(), DRAMCtrl::Rank::prechargeEvent, PWR_ACT_PDN, PWR_IDLE, PWR_PRE_PDN, PWR_SREF, DRAMCtrl::Rank::pwrState, DRAMCtrl::DRAMPacket::rank, DRAMCtrl::DRAMPacket::rankRef, DRAMCtrl::Rank::readEntries, REF_PRE, DRAMCtrl::Rank::refreshEvent, DRAMCtrl::Rank::refreshState, respondEvent, respQueue, retryRdReq, QoS::MemCtrl::schedule(), Event::scheduled(), SlavePort::sendRetryReq(), Drainable::signalDrainDone(), QoS::MemCtrl::totalReadQueueSize, and QoS::MemCtrl::totalWriteQueueSize.

Referenced by DRAMCtrl().

◆ pruneBurstTick()

void DRAMCtrl::pruneBurstTick ( )

private

Remove commands that have already issued from burstTicks.

Definition at line 934 of file dram_ctrl.cc.

References burstTicks, curTick(), and DPRINTF.

Referenced by doDRAMAccess(), and getCtrlAddr().

◆ readQueueFull()

bool DRAMCtrl::readQueueFull ( unsigned int pktCount ) const

private

Check if the read queue has room for more entries.

Parameters

pktCount The number of entries needed in the read queue

Returns: true if read queue is full, false otherwise

Definition at line 285 of file dram_ctrl.cc.

References DPRINTF, readBufferSize, respQueue, and QoS::MemCtrl::totalReadQueueSize.

Referenced by addToReadQueue(), and recvTimingReq().

◆ recvAtomic()

Tick DRAMCtrl::recvAtomic ( PacketPtr pkt )

protected

Definition at line 265 of file dram_ctrl.cc.

References AbstractMemory::access(), Packet::cacheResponding(), Packet::cmdString(), DPRINTF, Packet::getAddr(), Packet::hasData(), panic_if, tCL, tRCD, and tRP.

◆ recvFunctional()

void DRAMCtrl::recvFunctional ( PacketPtr pkt )

protected

Definition at line 2878 of file dram_ctrl.cc.

References AbstractMemory::functionalAccess().

◆ recvTimingReq()

bool DRAMCtrl::recvTimingReq ( PacketPtr pkt )

protected

◆ sortTime()

static bool DRAMCtrl::sortTime	(	const Command &	cmd,
		const Command &	cmd_next
	)

inlinestaticprivate

Function for sorting Command structures based on timeStamp.

Parameters

a	Memory Command
next	Memory Command

Returns: true if timeStamp of Command 1 < timeStamp of Command 2

Definition at line 1232 of file dram_ctrl.hh.

References allRanksDrained(), drain(), drainResume(), DRAMCtrl(), getPort(), init(), InvalidPortID, MipsISA::p, DRAMCtrl::MemoryPort::recvAtomic(), DRAMCtrl::MemoryPort::recvFunctional(), DRAMCtrl::MemoryPort::recvTimingReq(), startup(), and DRAMCtrl::Command::timeStamp.

Referenced by DRAMCtrl::Rank::flushCmdList().

◆ startup()

void DRAMCtrl::startup ( )

overridevirtual

startup() is the final initialization call before simulation.

All state is initialized (including unserialized state, if any, such as the curTick() value), so this is the appropriate place to schedule initial event(s) for objects that need them.

Reimplemented from SimObject.

Definition at line 241 of file dram_ctrl.cc.

References curTick(), divCeil(), isTimingMode, System::isTimingMode(), nextBurstAt, MipsISA::r, ranks, AbstractMemory::system(), tCK, timeStampOffset, tRCD, tREFI, and tRP.

Referenced by drainResume(), DRAMCtrl::Rank::name(), and sortTime().

◆ updatePowerStats()

void DRAMCtrl::updatePowerStats ( Rank & rank_ref )

private

This function increments the energy when called.

If stats are dumped periodically, note accumulated energy values will appear in the stats (even if the stats are reset). This is a result of the energy values coming from DRAMPower, and there is currently no support for resetting the state.

Parameters

rank	Current rank

◆ verifyMultiCmd()

Tick DRAMCtrl::verifyMultiCmd	(	Tick	cmd_tick,
		Tick	max_multi_cmd_split = `0`
	)

private

Check for command bus contention for multi-cycle (2 currently) command.

If there is contention, shift command(s) to next burst. Check verifies that the commands issued per burst is less than a defined max number, maxCommandsPerBurst. Therefore, contention per cycle is not verified and instead is done based on a burst window.

Parameters

cmd_tick	Initial tick of command, to be verified
max_multi_cmd_split	Maximum delay between commands

Returns: tick for command issue without contention

Definition at line 977 of file dram_ctrl.cc.

References burstDataCycles, burstTicks, DPRINTF, getBurstWindow(), and maxCommandsPerBurst.

Referenced by activateBank(), doDRAMAccess(), and getCtrlAddr().

◆ verifySingleCmd()

Tick DRAMCtrl::verifySingleCmd ( Tick cmd_tick )

private

Check for command bus contention for single cycle command.

If there is contention, shift command to next burst. Check verifies that the commands issued per burst is less than a defined max number, maxCommandsPerBurst. Therefore, contention per cycle is not verified and instead is done based on a burst window.

Parameters

cmd_tick Initial tick of command, to be verified

Returns: tick for command issue without contention

Definition at line 955 of file dram_ctrl.cc.

References burstDataCycles, burstTicks, DPRINTF, getBurstWindow(), and maxCommandsPerBurst.

Referenced by activateBank(), doDRAMAccess(), getCtrlAddr(), and prechargeBank().

◆ writeQueueFull()

bool DRAMCtrl::writeQueueFull ( unsigned int pktCount ) const

private

Check if the write queue has room for more entries.

Parameters

pktCount The number of entries needed in the write queue

Returns: true if write queue is full, false otherwise

Definition at line 296 of file dram_ctrl.cc.

References DPRINTF, QoS::MemCtrl::totalWriteQueueSize, and writeBufferSize.

Referenced by recvTimingReq().

Member Data Documentation

◆ activationLimit

const uint32_t DRAMCtrl::activationLimit

private

Definition at line 1048 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ activeRank

uint8_t DRAMCtrl::activeRank

private

Definition at line 1197 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ addrMapping

Enums::AddrMap DRAMCtrl::addrMapping

private

Definition at line 1062 of file dram_ctrl.hh.

Referenced by decodeAddr(), DRAMCtrl(), and init().

◆ backendLatency

const Tick DRAMCtrl::backendLatency

private

Pipeline latency of the backend and PHY.

Along with the frontend contribution, this latency is added to reads serviced by the DRAM.

Definition at line 1083 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processRespondEvent().

◆ bankGroupArch

const bool DRAMCtrl::bankGroupArch

private

Definition at line 1007 of file dram_ctrl.hh.

Referenced by activateBank(), doDRAMAccess(), and DRAMCtrl().

◆ bankGroupsPerRank

const uint32_t DRAMCtrl::bankGroupsPerRank

private

Definition at line 1006 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ banksPerRank

const uint32_t DRAMCtrl::banksPerRank

private

Definition at line 1008 of file dram_ctrl.hh.

Referenced by activateBank(), decodeAddr(), doDRAMAccess(), DRAMCtrl(), minBankPrep(), prechargeBank(), and DRAMCtrl::DRAMStats::regStats().

◆ burstDataCycles

const Tick DRAMCtrl::burstDataCycles

private

Definition at line 1055 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), getBurstWindow(), DRAMCtrl::DRAMStats::regStats(), verifyMultiCmd(), and verifySingleCmd().

◆ burstInterleave

const bool DRAMCtrl::burstInterleave

private

Definition at line 1054 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ burstLength

const uint32_t DRAMCtrl::burstLength

private

Definition at line 998 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ burstSize

const uint32_t DRAMCtrl::burstSize

private

Definition at line 1001 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), burstAlign(), decodeAddr(), doDRAMAccess(), DRAMCtrl(), processNextReqEvent(), recvTimingReq(), and DRAMCtrl::DRAMStats::regStats().

◆ burstTicks

std::unordered_multiset<Tick> DRAMCtrl::burstTicks

private

Holds count of commands issued in burst window starting at defined Tick.

This is used to ensure that the command bandwidth does not exceed the allowable media constraints.

Definition at line 983 of file dram_ctrl.hh.

Referenced by pruneBurstTick(), verifyMultiCmd(), and verifySingleCmd().

◆ clkResyncDelay

const Tick DRAMCtrl::clkResyncDelay

private

Definition at line 1044 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ columnsPerRowBuffer

const uint32_t DRAMCtrl::columnsPerRowBuffer

private

Definition at line 1003 of file dram_ctrl.hh.

Referenced by decodeAddr(), DRAMCtrl(), and init().

◆ columnsPerStripe

const uint32_t DRAMCtrl::columnsPerStripe

private

Definition at line 1004 of file dram_ctrl.hh.

Referenced by decodeAddr(), DRAMCtrl(), and init().

◆ dataClockSync

const bool DRAMCtrl::dataClockSync

private

Definition at line 1046 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ deviceBusWidth

const uint32_t DRAMCtrl::deviceBusWidth

private

Definition at line 997 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ deviceRowBufferSize

const uint32_t DRAMCtrl::deviceRowBufferSize

private

Definition at line 999 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ deviceSize

const uint32_t DRAMCtrl::deviceSize

private

The following are basic design parameters of the memory controller, and are initialized based on parameter values.

The rowsPerBank is determined based on the capacity, number of ranks and banks, the burst size, and the row buffer size.

Definition at line 996 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ devicesPerRank

const uint32_t DRAMCtrl::devicesPerRank

private

Definition at line 1000 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ enableDRAMPowerdown

bool DRAMCtrl::enableDRAMPowerdown

private

Enable or disable DRAM powerdown states.

Definition at line 1206 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processRespondEvent().

◆ frontendLatency

const Tick DRAMCtrl::frontendLatency

private

Pipeline latency of the controller frontend.

The frontend contribution is added to writes (that complete when they are in the write buffer) and reads that are serviced the write buffer.

Definition at line 1076 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), DRAMCtrl(), and processRespondEvent().

◆ isInWriteQueue

std::unordered_set<Addr> DRAMCtrl::isInWriteQueue

private

To avoid iterating over the write queue to check for overlapping transactions, maintain a set of burst addresses that are currently queued.

Since we merge writes to the same location we never have more than one address to the same burst address.

Definition at line 966 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), and processNextReqEvent().

◆ isTimingMode

bool DRAMCtrl::isTimingMode

private

Remember if the memory system is in timing mode.

Definition at line 128 of file dram_ctrl.hh.

Referenced by drainResume(), and startup().

◆ lastStatsResetTick

Tick DRAMCtrl::lastStatsResetTick

private

The time when stats were last reset used to calculate average power.

Definition at line 1203 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and DRAMCtrl::DRAMStats::resetStats().

◆ maxAccessesPerRow

const uint32_t DRAMCtrl::maxAccessesPerRow

private

Max column accesses (read and write) per row, before forcefully closing it.

Definition at line 1069 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), and DRAMCtrl::DRAMStats::regStats().

◆ maxCommandsPerBurst

unsigned int DRAMCtrl::maxCommandsPerBurst

private

Definition at line 1045 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), verifyMultiCmd(), and verifySingleCmd().

◆ memSchedPolicy

Enums::MemSched DRAMCtrl::memSchedPolicy

private

Memory controller configuration initialized based on parameter values.

Definition at line 1061 of file dram_ctrl.hh.

Referenced by chooseNext(), and DRAMCtrl().

◆ minWritesPerSwitch

const uint32_t DRAMCtrl::minWritesPerSwitch

private

Definition at line 1014 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processNextReqEvent().

◆ nextBurstAt

Tick DRAMCtrl::nextBurstAt

private

Till when must we wait before issuing next RD/WR burst?

Definition at line 1088 of file dram_ctrl.hh.

Referenced by chooseNextFRFCFS(), doDRAMAccess(), DRAMCtrl(), and startup().

◆ nextReqEvent

EventFunctionWrapper DRAMCtrl::nextReqEvent

private

Definition at line 730 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), drain(), and processNextReqEvent().

◆ nextReqTime

Tick DRAMCtrl::nextReqTime

private

The soonest you have to start thinking about the next request is the longest access time that can occur before nextBurstAt.

Assuming you need to precharge, open a new row, and access, it is tRP + tRCD + tCL.

Definition at line 1098 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), and processNextReqEvent().

◆ pageMgmt

Enums::PageManage DRAMCtrl::pageMgmt

private

Definition at line 1063 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ pendingDelete

std::unique_ptr<Packet> DRAMCtrl::pendingDelete

private

Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call.

Definition at line 1212 of file dram_ctrl.hh.

Referenced by accessAndRespond().

◆ port

MemoryPort DRAMCtrl::port

private

Our incoming port, for a multi-ported controller add a crossbar in front of it.

Definition at line 123 of file dram_ctrl.hh.

Referenced by accessAndRespond(), getPort(), init(), processNextReqEvent(), and processRespondEvent().

◆ prevArrival

Tick DRAMCtrl::prevArrival

private

Definition at line 1090 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and recvTimingReq().

◆ ranks

std::vector<Rank*> DRAMCtrl::ranks

private

Vector of ranks.

Definition at line 988 of file dram_ctrl.hh.

Referenced by activateBank(), allRanksDrained(), chooseNext(), decodeAddr(), doDRAMAccess(), drain(), drainResume(), DRAMCtrl(), minBankPrep(), processNextReqEvent(), and startup().

◆ ranksPerChannel

const uint32_t DRAMCtrl::ranksPerChannel

private

Definition at line 1005 of file dram_ctrl.hh.

Referenced by chooseNextFRFCFS(), decodeAddr(), doDRAMAccess(), DRAMCtrl(), minBankPrep(), processNextReqEvent(), and DRAMCtrl::DRAMStats::regStats().

◆ rankToRankDly

const Tick DRAMCtrl::rankToRankDly

private

Definition at line 1049 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ rdToWrDly

const Tick DRAMCtrl::rdToWrDly

private

Definition at line 1051 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ rdToWrDlySameBG

const Tick DRAMCtrl::rdToWrDlySameBG

private

Definition at line 1053 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ readBufferSize

const uint32_t DRAMCtrl::readBufferSize

private

Definition at line 1010 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), readQueueFull(), and DRAMCtrl::DRAMStats::regStats().

◆ readQueue

std::vector<DRAMPacketQueue> DRAMCtrl::readQueue

private

The controller's main read and write queues, with support for QoS reordering.

Definition at line 956 of file dram_ctrl.hh.

Referenced by addToReadQueue(), doDRAMAccess(), DRAMCtrl(), printQs(), processNextReqEvent(), and recvTimingReq().

◆ readsThisTime

uint32_t DRAMCtrl::readsThisTime

private

Definition at line 1016 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), and processNextReqEvent().

◆ respondEvent

EventFunctionWrapper DRAMCtrl::respondEvent

private

Definition at line 733 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), processNextReqEvent(), and processRespondEvent().

◆ respQueue

std::deque<DRAMPacket*> DRAMCtrl::respQueue

private

Response queue where read packets wait after we're done working with them, but it's not time to send the response yet.

The responses are stored separately mostly to keep the code clean and help with events scheduling. For all logical purposes such as sizing the read queue, this and the main read queue need to be added together.

Definition at line 976 of file dram_ctrl.hh.

Referenced by addToReadQueue(), drain(), printQs(), processNextReqEvent(), processRespondEvent(), and readQueueFull().

◆ retryRdReq

bool DRAMCtrl::retryRdReq

private

Remember if we have to retry a request when available.

Definition at line 133 of file dram_ctrl.hh.

Referenced by processRespondEvent(), and recvTimingReq().

◆ retryWrReq

bool DRAMCtrl::retryWrReq

private

Definition at line 134 of file dram_ctrl.hh.

Referenced by processNextReqEvent(), and recvTimingReq().

◆ rowBufferSize

const uint32_t DRAMCtrl::rowBufferSize

private

Definition at line 1002 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), init(), and DRAMCtrl::DRAMStats::regStats().

◆ rowsPerBank

uint32_t DRAMCtrl::rowsPerBank

private

Definition at line 1009 of file dram_ctrl.hh.

Referenced by decodeAddr(), and DRAMCtrl().

◆ stats

DRAMStats DRAMCtrl::stats

private

Definition at line 1194 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), doDRAMAccess(), DRAMCtrl(), prechargeBank(), processNextReqEvent(), and recvTimingReq().

◆ tAAD

const Tick DRAMCtrl::tAAD

private

Definition at line 1040 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tBURST

const Tick DRAMCtrl::tBURST

private

Definition at line 1025 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tBURST_MIN

const Tick DRAMCtrl::tBURST_MIN

private

Definition at line 1026 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tCCD_L

const Tick DRAMCtrl::tCCD_L

private

Definition at line 1028 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tCCD_L_WR

const Tick DRAMCtrl::tCCD_L_WR

private

Definition at line 1027 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tCK

const Tick M5_CLASS_VAR_USED DRAMCtrl::tCK

private

Basic memory timing parameters initialized based on parameter values.

Definition at line 1022 of file dram_ctrl.hh.

Referenced by activateBank(), doDRAMAccess(), DRAMCtrl(), prechargeBank(), and startup().

◆ tCL

const Tick DRAMCtrl::tCL

private

Definition at line 1030 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), and recvAtomic().

◆ tCS

const Tick DRAMCtrl::tCS

private

Definition at line 1024 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processNextReqEvent().

◆ timeStampOffset

uint64_t DRAMCtrl::timeStampOffset

private

Definition at line 1200 of file dram_ctrl.hh.

Referenced by activateBank(), doDRAMAccess(), DRAMCtrl(), prechargeBank(), and startup().

◆ tPPD

const Tick DRAMCtrl::tPPD

private

Definition at line 1039 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and prechargeBank().

◆ tRAS

const Tick DRAMCtrl::tRAS

private

Definition at line 1032 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tRCD

const Tick DRAMCtrl::tRCD

private

Definition at line 1029 of file dram_ctrl.hh.

Referenced by activateBank(), doDRAMAccess(), DRAMCtrl(), minBankPrep(), recvAtomic(), and startup().

◆ tREFI

const Tick DRAMCtrl::tREFI

private

Definition at line 1036 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and startup().

◆ tRFC

const Tick DRAMCtrl::tRFC

private

Definition at line 1035 of file dram_ctrl.hh.

Referenced by DRAMCtrl().

◆ tRP

const Tick DRAMCtrl::tRP

private

Definition at line 1031 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), minBankPrep(), prechargeBank(), recvAtomic(), and startup().

◆ tRRD

const Tick DRAMCtrl::tRRD

private

Definition at line 1037 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tRRD_L

const Tick DRAMCtrl::tRRD_L

private

Definition at line 1038 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tRTP

const Tick DRAMCtrl::tRTP

private

Definition at line 1034 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tRTW

const Tick DRAMCtrl::tRTW

private

Definition at line 1023 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processNextReqEvent().

◆ twoCycleActivate

const uint8_t DRAMCtrl::twoCycleActivate

private

Definition at line 1047 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tWR

const Tick DRAMCtrl::tWR

private

Definition at line 1033 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tXAW

const Tick DRAMCtrl::tXAW

private

Definition at line 1041 of file dram_ctrl.hh.

Referenced by activateBank(), and DRAMCtrl().

◆ tXP

const Tick DRAMCtrl::tXP

private

Definition at line 1042 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ tXS

const Tick DRAMCtrl::tXS

private

Definition at line 1043 of file dram_ctrl.hh.

Referenced by drain(), DRAMCtrl(), and processNextReqEvent().

◆ writeBufferSize

const uint32_t DRAMCtrl::writeBufferSize

private

Definition at line 1011 of file dram_ctrl.hh.

Referenced by addToWriteQueue(), DRAMCtrl(), processNextReqEvent(), DRAMCtrl::DRAMStats::regStats(), and writeQueueFull().

◆ writeHighThreshold

const uint32_t DRAMCtrl::writeHighThreshold

private

Definition at line 1012 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processNextReqEvent().

◆ writeLowThreshold

const uint32_t DRAMCtrl::writeLowThreshold

private

Definition at line 1013 of file dram_ctrl.hh.

Referenced by DRAMCtrl(), and processNextReqEvent().

◆ writeQueue

std::vector<DRAMPacketQueue> DRAMCtrl::writeQueue

private

Definition at line 957 of file dram_ctrl.hh.

Referenced by addToReadQueue(), addToWriteQueue(), doDRAMAccess(), DRAMCtrl(), printQs(), processNextReqEvent(), and recvTimingReq().

◆ writesThisTime

uint32_t DRAMCtrl::writesThisTime

private

Definition at line 1015 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), DRAMCtrl(), and processNextReqEvent().

◆ wrToRdDly

const Tick DRAMCtrl::wrToRdDly

private

Definition at line 1050 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

◆ wrToRdDlySameBG

const Tick DRAMCtrl::wrToRdDlySameBG

private

Definition at line 1052 of file dram_ctrl.hh.

Referenced by doDRAMAccess(), and DRAMCtrl().

The documentation for this class was generated from the following files:

mem/dram_ctrl.hh
mem/dram_ctrl.cc

Classes

Public Member Functions

Protected Member Functions

Private Types

Private Member Functions

Static Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ DRAMPacketQueue

Member Enumeration Documentation

◆ PowerState

◆ RefreshState

Constructor & Destructor Documentation

◆ DRAMCtrl()

Member Function Documentation

◆ accessAndRespond()

◆ activateBank()

◆ addToReadQueue()

◆ addToWriteQueue()

◆ allRanksDrained()

◆ burstAlign()

◆ chooseNext()

◆ chooseNextFRFCFS()

◆ decodeAddr()

◆ doDRAMAccess()

◆ drain()

◆ drainResume()

◆ getBurstWindow()

◆ getCtrlAddr()

◆ getPort()

◆ init()

◆ minBankPrep()

◆ prechargeBank()

◆ printQs()

◆ processNextReqEvent()

◆ processRespondEvent()

◆ pruneBurstTick()

◆ readQueueFull()

◆ recvAtomic()

◆ recvFunctional()

◆ recvTimingReq()

◆ sortTime()

◆ startup()

◆ updatePowerStats()

◆ verifyMultiCmd()

◆ verifySingleCmd()

◆ writeQueueFull()

Member Data Documentation

◆ activationLimit

◆ activeRank

◆ addrMapping

◆ backendLatency

◆ bankGroupArch

◆ bankGroupsPerRank

◆ banksPerRank

◆ burstDataCycles

◆ burstInterleave

◆ burstLength

◆ burstSize

◆ burstTicks

◆ clkResyncDelay

◆ columnsPerRowBuffer

◆ columnsPerStripe

◆ dataClockSync

◆ deviceBusWidth

◆ deviceRowBufferSize

◆ deviceSize

◆ devicesPerRank

◆ enableDRAMPowerdown

◆ frontendLatency

◆ isInWriteQueue

◆ isTimingMode

◆ lastStatsResetTick

◆ maxAccessesPerRow

◆ maxCommandsPerBurst

◆ memSchedPolicy

◆ minWritesPerSwitch

◆ nextBurstAt