一. 分析TLM2示例的基本流程方法
1.从sc_main()开始，发现各个模块类的内部重要模块，以及对外连接的public端口或socket，理清基本has和is关系；
2.看顶层类之成员类的构造函数，理清模块类的端口连接关系；（socket是稍微融合了的接口）
3.从前往后，从发起者到目标，看每个模块的method和thread；然后再从后往前，从目标到发起者，思考nb_ b_ 传输关系。
二. 示例分析
选用示例为： D:\systemc-2.3.3\examples\tlm\at_1_phase\
仅加入了汉语注释，英文注释为示例作者所加入；真诚感谢项目作者无私开源的倾情奉献！
（1.） 看sc_main()，发现类的成员关系，理清基本has和is关系
入口函数int sc_main(int argc, char* argv)在项目同名的cpp文件中：at_1_phase.cpp
///文件at_1_phase.cpp的编译代码
//===================================================================== /// @file example_main.cpp /// /// @brief Example main instantiates the example system top and starts /// the systemc simulator /// //===================================================================== // Original Authors: // Bill Bunton, ESLX // Anna Keist, ESLX // Charles Wilson, ESLX // Jack Donovan, ESLX //===================================================================== // define REPORT_DEFINE_GLOBALS in one location only #define REPORT_DEFINE_GLOBALS #include "reporting.h" // reporting utilities #include "at_1_phase_top.h" // top module #include "tlm.h" // TLM header //===================================================================== /// @fn sc_main // /// @brief SystemC entry point // /// @details /// This is the SystemC entry point for the example system. The argc and argv /// parameters are not used. Simulation runtime is not specified when /// sc_start() is called, the examples traffic generator will run to /// completion, ending the simulation. /// //===================================================================== int // return status sc_main // SystemC entry point (int argc // argument count ,char *argv[] // argument vector ) { REPORT_ENABLE_ALL_REPORTING (); //LL::实施第一步，通过example_system_top类来理清类的关系，该类定义在文件：examples\tlm\at_1_phase\include\at_1_phase_top.h中 example_system_top top("top"); // instantiate a exmaple top module sc_core::sc_start(); // start the simulation return 0; // return okay status }最顶层系统的构成模块
从example_system_top的成员变量可以看出，宏观上本系统总共有5个子模块构成，如图Figure1：
SimpleBusAT<2, 2> m_bus; ///< simple bus at_target_1_phase m_at_target_1_phase_1; ///< instance 1 target at_target_1_phase m_at_target_1_phase_2; ///< instance 2 target initiator_top m_initiator_1; ///< instance 1 initiator initiator_top m_initiator_2; ///< instance 2 initiator
//===================================================================== /// @file example_system_top.h /// @brief This class instantiates components that compose the TLM2 /// example system called at_1_phase //===================================================================== // Original Authors: // Anna Keist, ESLX // Bill Bunton, ESLX // Jack Donovan, ESLX //===================================================================== #ifndef __EXAMPLE_SYSTEM_TOP_H__ #define __EXAMPLE_SYSTEM_TOP_H__ #include "reporting.h" // common reporting code #include "at_target_1_phase.h" // at memory target #include "initiator_top.h" // processor abstraction initiator #include "models/SimpleBusAT.h" // Bus/Router Implementation /// Top wrapper Module class example_system_top : public sc_core::sc_module // SC base class { public: /// Constructor example_system_top ( sc_core::sc_module_name name); //Member Variables =========================================================== //LL::本例程仿真的系统中包含（has）一条总线bus，两个发起者顶层模块initiator_top，两个目标模块target，如下图所示。 private: SimpleBusAT<2, 2> m_bus; ///< simple bus at_target_1_phase m_at_target_1_phase_1; ///< instance 1 target at_target_1_phase m_at_target_1_phase_2; ///< instance 2 target initiator_top m_initiator_1; ///< instance 1 initiator initiator_top m_initiator_2; ///< instance 2 initiator }; #endif /* __EXAMPLE_SYSTEM_TOP_H__ */
图一：
查看initiator_top类中子模块的组成
子模块组成，看initiator_top.h；
initiator_top类，有三个主要模块组成：
tlm::tlm_initiator_socket<> initiator_socket;
select_initiator m_initiator; traffic_generator m_traffic_gen;
//===================================================================== /// @file initiator_top.h // /// @brief Initiator top module contains a traffic generator and an /// example tlm initiator module // //===================================================================== // Original Authors: // Bill Bunton, ESLX // Charles Wilson, ESLX // Jack Donovan, ESLX //===================================================================== #ifndef __INITIATOR_TOP_H__ #define __INITIATOR_TOP_H__ #include "tlm.h" // TLM headers #include "select_initiator.h" // AT initiator #include "traffic_generator.h" // traffic generator class initiator_top : public sc_core::sc_module , virtual public tlm::tlm_bw_transport_if<> // backward non-blocking interface { //Member Methods ===================================================== public: //===================================================================== /// @fn initiator_top::initiator_top // /// @brief initiator_top constructor // /// @details /// Initiator top module contains a traffic generator and an example /// unique initiator module // //===================================================================== initiator_top ( sc_core::sc_module_name name ///< module name , const unsigned int ID ///< initiator ID , sc_dt::uint64 base_address_1 ///< first base address , sc_dt::uint64 base_address_2 ///< second base address , unsigned int active_txn_count ///< Max number of active transactions ); private: /// Not Implemented for this example but required by the initiator socket void invalidate_direct_mem_ptr ( sc_dt::uint64 start_range , sc_dt::uint64 end_range ); /// Not Implemented for this example but require by the initiator socket tlm::tlm_sync_enum nb_transport_bw ( tlm::tlm_generic_payload &payload , tlm::tlm_phase &phase , sc_core::sc_time &delta ); //Member Variables/Objects =========================================== public: tlm::tlm_initiator_socket<> initiator_socket; ///< processor socket private: typedef tlm::tlm_generic_payload *gp_ptr; ///< Generic Payload pointer //LL::m_request_fifo 和 m_response_fifo 是为两个内部模块的接口搭桥之用。宏观上，前者是送出去，后者是收进来。 sc_core::sc_fifo <gp_ptr> m_request_fifo; ///< request SC FIFO sc_core::sc_fifo <gp_ptr> m_response_fifo; ///< response SC FIFO const unsigned int m_ID; ///< initiator ID select_initiator m_initiator; ///< TLM initiator instance traffic_generator m_traffic_gen; ///< traffic generator instance }; #endif /* __INITIATOR_TOP_H__ */
查看select_initiator类的重要成员
通过头文件select_initiator.h，
select_initiator类的主要成员为三个： sc_core::sc_port<sc_core::sc_fifo_in_if <gp_ptr> > request_in_port; sc_core::sc_port<sc_core::sc_fifo_out_if <gp_ptr> > response_out_port; tlm::tlm_initiator_socket<> initiator_socket;
//============================================================================== /// @file select_initiator.h // /// @brief This is a TLM AT initiator // //============================================================================= // Original Authors: // Bill Bunton, ESLX // Anna Keist, ESLX // //============================================================================= #ifndef __SELECT_INITIATOR_H__ #define __SELECT_INITIATOR_H__ #include "tlm.h" // TLM headers #include "tlm_utils/peq_with_get.h" // Payload event queue FIFO #include <map> // STL map class select_initiator /// TLM AT select_initiator : public sc_core::sc_module /// inherit from SC module base clase , virtual public tlm::tlm_bw_transport_if<> /// inherit from TLM "backward interface" { SC_HAS_PROCESS(select_initiator); //============================================================================== // Ports, exports and Sockets //============================================================================== typedef tlm::tlm_generic_payload *gp_ptr; // generic payload public: //LL::两层template分别起到的作用？ sc_core::sc_port<sc_core::sc_fifo_in_if <gp_ptr> > request_in_port; sc_core::sc_port<sc_core::sc_fifo_out_if <gp_ptr> > response_out_port; tlm::tlm_initiator_socket<> initiator_socket; //============================================================================= /// @fn select_initiator /// /// @brief Constructor for AT Initiator /// /// @details /// Generic AT Initiator used in several examples. /// Constructor offers several parameters for customization /// //============================================================================= select_initiator // constructor ( sc_core::sc_module_name name // module name , const unsigned int ID // initiator ID , sc_core::sc_time end_rsp_delay // delay ); //============================================================================= /// @fn at_target_2_phase::initiator_thread /// /// @brief Initiator thread /// /// @details /// This thread takes generic payloads (gp) from the request FIFO that connects /// to the traffic generator and initiates. When the transaction completes the /// gp is placed in the response FIFO to return it to the traffic generator. //============================================================================= private: void initiator_thread (void); // initiator thread //============================================================================= /// @fn at_target_2_phase::send_end_rsp_method /// /// @brief Send end response method /// /// @details /// This routine takes transaction responses from the m_send_end_rsp_PEQ. /// It contains the state machine to manage the communication path to the /// targets. This method is registered as an SC_METHOD with the SystemC /// kernel and is sensitive to m_send_end_rsp_PEQ.get_event() //============================================================================= private: void send_end_rsp_method(void); // send end response method //============================================================================= /// @brief Implementation of call from targets. // /// @details /// This is the ultimate destination of the nb_transport_bw call from /// the targets after being routed trough a Bus // //===================================================================== tlm::tlm_sync_enum nb_transport_bw( // nb_transport tlm::tlm_generic_payload& transaction, // transaction tlm::tlm_phase& phase, // transaction phase sc_core::sc_time& time); // elapsed time //============================================================================== // Required but not implemented member methods //============================================================================== void invalidate_direct_mem_ptr( // invalidate_direct_mem_ptr sc_dt::uint64 start_range, // start range sc_dt::uint64 end_range); // end range //============================================================================== // Private member variables and methods //============================================================================== private: enum previous_phase_enum {Rcved_UPDATED_enum // Received TLM_UPDATED d ,Rcved_ACCEPTED_enum // Received ACCEPTED ,Rcved_END_REQ_enum // Received TLM_BEGIN_RESP }; typedef std::map<tlm::tlm_generic_payload *, previous_phase_enum> waiting_bw_path_map; waiting_bw_path_map m_waiting_bw_path_map; // Wait backward path map sc_core::sc_event m_enable_next_request_event; tlm_utils::peq_with_get<tlm::tlm_generic_payload> m_send_end_rsp_PEQ; // send end response PEQ const unsigned int m_ID; // initiator ID const sc_core::sc_time m_end_rsp_delay; // end response delay bool m_enable_target_tracking; // ? remove }; #endif /* __SELECT_INITIATOR_H__ */
traffic_generator类的主要成员
public: sc_core::sc_port<sc_core::sc_fifo_out_if <gp_ptr> > request_out_port; sc_core::sc_port<sc_core::sc_fifo_in_if <gp_ptr> > response_in_port;
源代码文件traffic_generator.h
//===================================================================== /// @file traffic_generator.h // /// @brief traffic_generator class header // //===================================================================== // Authors: // Bill Bunton, ESLX // Charles Wilson, ESLX // Jack Donovan, ESLX //==================================================================== #ifndef __TRAFFIC_GENERATOR_H__ #define __TRAFFIC_GENERATOR_H__ #include "tlm.h" // TLM headers #include <queue> // queue header from std lib class traffic_generator // traffic_generator : public sc_core::sc_module // sc_module { // Member Methods ==================================================== public: //============================================================================= /// @fn traffic_generator // /// @brief traffic_generator constructor // /// @details /// Initializes Traffice Generator iIncluding active transaction count. // //============================================================================= //LL::构造函数 traffic_generator ( sc_core::sc_module_name name ///< module name for SC , const unsigned int ID ///< initiator ID , sc_dt::uint64 base_address_1 ///< first base address , sc_dt::uint64 base_address_2 ///< second base address , unsigned int active_txn_count ///< Max number of active transactions //LL::可以同时有多个事务在被系统处理之中 ); //============================================================================= /// @fn traffic_generator_thread // /// @brief traffic_generator processing thread // /// @details /// Method actually called by SC simulator to generate and /// check traffic. Generate Writes then Reads to check the /// Writes // //============================================================================= void traffic_generator_thread ( void ); //----------------------------------------------------------------------------- // Check Complete method void check_complete (void); //----------------------------------------------------------------------------- // Check All Complete method void check_all_complete (void); // memory manager (queue) //LL::每个事务净核类中的数据指针指向的数据存储区域的大小为4个字节 static const unsigned int m_txn_data_size = 4; // transaction size //LL::tg_queue_c是理论上所说的内存管理器类 of tlm_generic_payload的对象。 //LL::定义出即将发送的净核事务类的对象，并放在FIFO队列中。然后依次出队并发送出去 class tg_queue_c /// memory managed queue class : public tlm::tlm_mm_interface /// implements memory management IF { public: tg_queue_c /// tg_queue_c constructor ( void ) { } //LL::new一个净核事务类的对象，并排队放入自己的成员m_queue之中。new一块连续的存储区域，携带事务的数据信息， //并将地址放入刚刚new的净核事务类对象的相关成员中(unsigned char* m_data)。 void enqueue /// enqueue entry (create) ( void ) { //LL:: tlm_generic_payload 的两个默认构造函数： tlm_generic_payload(); explicit tlm_generic_payload(tlm_mm_interface* mm); //LL:: 此处时显式调用第二个构造函数 tlm::tlm_generic_payload *transaction_ptr = new tlm::tlm_generic_payload ( this ); /// transaction pointer unsigned char *data_buffer_ptr = new unsigned char [ m_txn_data_size ]; /// data buffer pointer transaction_ptr->set_data_ptr ( data_buffer_ptr ); m_queue.push ( transaction_ptr ); } //LL::出队一个事务净核类的对象 tlm::tlm_generic_payload * /// transaction pointer dequeue /// dequeue entry ( void ) { tlm::tlm_generic_payload *transaction_ptr = m_queue.front (); m_queue.pop(); return transaction_ptr; } //LL::当事务净核类的对象是从一个内存管理器中分配而来时，release将导致这个类对象的引用计数减一，当减至0时， //将调用tlm_mm_interface::free()把该对象释放并归还内存管理器的内存pool。这里的实现是下面定义的free()函数，将事务净核类对象的放回入队m_queue中。 void release /// release entry ( tlm::tlm_generic_payload *transaction_ptr /// transaction pointer ) { transaction_ptr->release (); } //LL::内存池内存为空，没有tlm_generic_payload 对象存在于内存池中。此例中表示，所有的tlm_generic_payload对象都处在被系统的处理之中。 bool /// true / false is_empty /// queue empty ( void ) { return m_queue.empty (); } //LL::返回这个内存池可管理的tlm_generic_payload对象的个数。 size_t /// queue size size /// queue size ( void ) { return m_queue.size (); } //LL::实现tlm::tlm_mm_interface::free()，归还一个tlm_generic_payload对象给pool。 //这个pool是一个抽象的代称，此例中是用一个指针队列来做pool，std::queue<tlm::tlm_generic_payload*> void free /// return transaction ( tlm::tlm_generic_payload *transaction_ptr /// to the pool ) { transaction_ptr->reset(); m_queue.push ( transaction_ptr ); } private: std::queue<tlm::tlm_generic_payload*> m_queue; /// queue }; //============================================================================= // Member Variables private: typedef tlm::tlm_generic_payload *gp_ptr; // pointer to a generic payload const unsigned int m_ID; // initiator ID sc_dt::uint64 m_base_address_1; // first base address//LL::作用？ sc_dt::uint64 m_base_address_2; // second base address //LL::m_transaction_queue是内存管理器类 of tlm_generic_payload 对象内存池 tg_queue_c m_transaction_queue; // transaction queue //LL::正在处理中的事务净核类的对象的个数 unsigned int m_active_txn_count; // active transaction count bool m_check_all; public: /// Port for requests to the initiator sc_core::sc_port<sc_core::sc_fifo_out_if <gp_ptr> > request_out_port; /// Port for responses from the initiator sc_core::sc_port<sc_core::sc_fifo_in_if <gp_ptr> > response_in_port; }; #endif /* __TRAFFIC_GENERATOR_H__ */针对initiator_top模块，进入第二个步骤，分析模块间的端口连接关系。
综上，结合initiator_top类的构造函数可得下图bind关系：
构造函数源代码：
//===================================================================== /// @file initiator_top.cpp // /// @brief Implements instantiation and interconnect of traffic_generator /// and an initiator via sc_fifos for at_1_phase_example // //===================================================================== // Original Authors: // Bill Bunton, ESLX // Charles Wilson, ESLX // Anna Keist, ESLX // Jack Donovan, ESLX //===================================================================== #include "initiator_top.h" // Top traffic generator & initiator #include "reporting.h" // reporting macro helpers static const char *filename = "initiator_top.cpp"; ///< filename for reporting /// Constructor initiator_top::initiator_top ( sc_core::sc_module_name name , const unsigned int ID , sc_dt::uint64 base_address_1 , sc_dt::uint64 base_address_2 , unsigned int active_txn_count ) :sc_module (name) // module name for top ,initiator_socket ("at_initiator_socket") // TLM socket ,m_ID (ID) // initiator ID ,m_initiator // Init initiator ("m_initiator_1_phase" ,ID ,sc_core::sc_time(7, sc_core::SC_NS) // set initiator end rsp delay ) ,m_traffic_gen // Init traffic Generator //LL::本例中系统生成了两个 ("m_traffic_gen" ,ID ,base_address_1 // first base address ,base_address_2 // second base address ,active_txn_count // Max active transactions ) {//LL::通过initiator_top::m_request_fifo 把其两个成员traffic_gen和select_initiator的两个sc_port连接起来。 /// Bind ports to m_request_fifo between m_initiator and m_traffic_gen m_traffic_gen.request_out_port (m_request_fifo); m_initiator.request_in_port (m_request_fifo); /// Bind ports to m_response_fifo between m_initiator and m_traffic_gen m_initiator.response_out_port (m_response_fifo); m_traffic_gen.response_in_port (m_response_fifo); /// Bind initiator-socket to initiator-socket hierarchical connection m_initiator.initiator_socket(initiator_socket); } //===================================================================== /// @fn initiator_top::invalidate_direct_mem_ptr /// /// @brief Unused mandatory virtual implementation /// /// @details /// No DMI is implemented in this example so unused /// //===================================================================== void initiator_top::invalidate_direct_mem_ptr ( sc_dt::uint64 start_range ,sc_dt::uint64 end_range ) { std::ostringstream msg; // log message msg.str (""); msg << "Initiator: " << m_ID << " Not implemented"; REPORT_ERROR(filename, __FUNCTION__, msg.str()); } // end invalidate_direct_mem_ptr //===================================================================== /// @fn initiator_top::nb_transport_bw // /// @brief Unused mandatory virtual implementation /// /// @details /// Unused implementation from hierarchichal connectivity of /// Initiator sockets. /// //===================================================================== tlm::tlm_sync_enum initiator_top::nb_transport_bw ( tlm::tlm_generic_payload &payload ,tlm::tlm_phase &phase ,sc_core::sc_time &delta ) { std::ostringstream msg; // log message msg.str (""); msg << "Initiator: " << m_ID << " Not implemented, for hierachical connection of initiator socket"; REPORT_ERROR(filename, __FUNCTION__, msg.str()); return tlm::TLM_COMPLETED; } // end nb_transport_bw图：
对外部而言，initiator_top对外的一个连接通道是 该类的要给公有成员initiator_socket
改图分析了transaction的 payload数据流向，以及如何发送到initiator_top外部去的。
接下来先看看Bus的组成成员
总线类SimpleBusAT类的主要主要构成主要有两类个socket数组
public: target_socket_type target_socket[NR_OF_INITIATORS]; initiator_socket_type initiator_socket[NR_OF_TARGETS];
#ifndef __SIMPLEBUSAT_H__ #define __SIMPLEBUSAT_H__ //#include <systemc> #include "tlm.h" #include "tlm_utils/simple_target_socket.h" #include "tlm_utils/simple_initiator_socket.h" #include "tlm_utils/peq_with_get.h" //LL::本例中，发起者的数量是2， 目标的数量也是2 template <int NR_OF_INITIATORS, int NR_OF_TARGETS> class SimpleBusAT : public sc_core::sc_module { public: typedef tlm::tlm_generic_payload transaction_type; typedef tlm::tlm_phase phase_type; typedef tlm::tlm_sync_enum sync_enum_type; typedef tlm_utils::simple_target_socket_tagged<SimpleBusAT> target_socket_type; typedef tlm_utils::simple_initiator_socket_tagged<SimpleBusAT> initiator_socket_type; public: target_socket_type target_socket[NR_OF_INITIATORS]; initiator_socket_type initiator_socket[NR_OF_TARGETS]; public: SC_HAS_PROCESS(SimpleBusAT); SimpleBusAT(sc_core::sc_module_name name) : sc_core::sc_module(name), mRequestPEQ("requestPEQ"), mResponsePEQ("responsePEQ") { for (unsigned int i = 0; i < NR_OF_INITIATORS; ++i) { //LL:: 赋值给simple_target_socket的一个成员 class fw_process::m_nb_transport_ptr target_socket[i].register_nb_transport_fw(this, &SimpleBusAT::initiatorNBTransport, i); target_socket[i].register_transport_dbg(this, &SimpleBusAT::transportDebug, i); target_socket[i].register_get_direct_mem_ptr(this, &SimpleBusAT::getDMIPointer, i); } for (unsigned int i = 0; i < NR_OF_TARGETS; ++i) { initiator_socket[i].register_nb_transport_bw(this, &SimpleBusAT::targetNBTransport, i); initiator_socket[i].register_invalidate_direct_mem_ptr(this, &SimpleBusAT::invalidateDMIPointers, i); } SC_THREAD(RequestThread); SC_THREAD(ResponseThread); } // // Dummy decoder: // - address[31-28]: portId // - address[27-0]: masked address // unsigned int getPortId(const sc_dt::uint64& address) { return (unsigned int)address >> 28; } sc_dt::uint64 getAddressOffset(unsigned int portId) { return portId << 28; } sc_dt::uint64 getAddressMask(unsigned int portId) { return 0xfffffff; } unsigned int decode(const sc_dt::uint64& address) { // decode address: // - return initiator socket id return getPortId(address); } // // AT protocol // void RequestThread() { while (true) { wait(mRequestPEQ.get_event()); transaction_type* trans; while ((trans = mRequestPEQ.get_next_transaction())!=0) { unsigned int portId = decode(trans->get_address()); assert(portId < NR_OF_TARGETS); initiator_socket_type* decodeSocket = &initiator_socket[portId]; trans->set_address(trans->get_address() & getAddressMask(portId)); // Fill in the destination port PendingTransactionsIterator it = mPendingTransactions.find(trans); assert(it != mPendingTransactions.end()); it->second.to = decodeSocket; phase_type phase = tlm::BEGIN_REQ; sc_core::sc_time t = sc_core::SC_ZERO_TIME; // FIXME: No limitation on number of pending transactions // All targets (that return false) must support multiple transactions switch ((*decodeSocket)->nb_transport_fw(*trans, phase, t)) { case tlm::TLM_ACCEPTED: case tlm::TLM_UPDATED: // Transaction not yet finished if (phase == tlm::BEGIN_REQ) { // Request phase not yet finished wait(mEndRequestEvent); } else if (phase == tlm::END_REQ) { // Request phase finished, but response phase not yet started wait(t); } else if (phase == tlm::BEGIN_RESP) { mResponsePEQ.notify(*trans, t); // Not needed to send END_REQ to initiator continue; } else { // END_RESP assert(0); exit(1); } // only send END_REQ to initiator if BEGIN_RESP was not already send if (it->second.from) { phase = tlm::END_REQ; t = sc_core::SC_ZERO_TIME; (*it->second.from)->nb_transport_bw(*trans, phase, t); } break; case tlm::TLM_COMPLETED: // Transaction finished mResponsePEQ.notify(*trans, t); // reset to destination port (we must not send END_RESP to target) it->second.to = 0; wait(t); break; default: assert(0); exit(1); }; } } } void ResponseThread() { while (true) { wait(mResponsePEQ.get_event()); transaction_type* trans; while ((trans = mResponsePEQ.get_next_transaction())!=0) { PendingTransactionsIterator it = mPendingTransactions.find(trans); assert(it != mPendingTransactions.end()); phase_type phase = tlm::BEGIN_RESP; sc_core::sc_time t = sc_core::SC_ZERO_TIME; target_socket_type* initiatorSocket = it->second.from; // if BEGIN_RESP is send first we don't have to send END_REQ anymore it->second.from = 0; switch ((*initiatorSocket)->nb_transport_bw(*trans, phase, t)) { case tlm::TLM_COMPLETED: // Transaction finished wait(t); break; case tlm::TLM_ACCEPTED: case tlm::TLM_UPDATED: // Transaction not yet finished wait(mEndResponseEvent); break; default: assert(0); exit(1); }; // forward END_RESP to target if (it->second.to) { phase = tlm::END_RESP; t = sc_core::SC_ZERO_TIME; sync_enum_type r = (*it->second.to)->nb_transport_fw(*trans, phase, t); assert(r == tlm::TLM_COMPLETED); (void)r; } mPendingTransactions.erase(it); trans->release(); } } } // // interface methods // sync_enum_type initiatorNBTransport(int initiator_id, transaction_type& trans, phase_type& phase, sc_core::sc_time& t) { if (phase == tlm::BEGIN_REQ) { trans.acquire(); addPendingTransaction(trans, 0, initiator_id); mRequestPEQ.notify(trans, t); } else if (phase == tlm::END_RESP) { mEndResponseEvent.notify(t); return tlm::TLM_COMPLETED; } else { std::cout << "ERROR: '" << name() << "': Illegal phase received from initiator." << std::endl; assert(false); exit(1); } return tlm::TLM_ACCEPTED; } sync_enum_type targetNBTransport(int portId, transaction_type& trans, phase_type& phase, sc_core::sc_time& t) { if (phase != tlm::END_REQ && phase != tlm::BEGIN_RESP) { std::cout << "ERROR: '" << name() << "': Illegal phase received from target." << std::endl; assert(false); exit(1); } mEndRequestEvent.notify(t); if (phase == tlm::BEGIN_RESP) { mResponsePEQ.notify(trans, t); } return tlm::TLM_ACCEPTED; } unsigned int transportDebug(int initiator_id, transaction_type& trans) { unsigned int portId = decode(trans.get_address()); assert(portId < NR_OF_TARGETS); initiator_socket_type* decodeSocket = &initiator_socket[portId]; trans.set_address( trans.get_address() & getAddressMask(portId) ); return (*decodeSocket)->transport_dbg(trans); } bool limitRange(unsigned int portId, sc_dt::uint64& low, sc_dt::uint64& high) { sc_dt::uint64 addressOffset = getAddressOffset(portId); sc_dt::uint64 addressMask = getAddressMask(portId); if (low > addressMask) { // Range does not overlap with addressrange for this target return false; } low += addressOffset; if (high > addressMask) { high = addressOffset + addressMask; } else { high += addressOffset; } return true; } bool getDMIPointer(int initiator_id, transaction_type& trans, tlm::tlm_dmi& dmi_data) { // FIXME: DMI not supported for AT bus? sc_dt::uint64 address = trans.get_address(); unsigned int portId = decode(address); assert(portId < NR_OF_TARGETS); initiator_socket_type* decodeSocket = &initiator_socket[portId]; sc_dt::uint64 maskedAddress = address & getAddressMask(portId); trans.set_address(maskedAddress); bool result = (*decodeSocket)->get_direct_mem_ptr(trans, dmi_data); if (result) { // Range must contain address assert(dmi_data.get_start_address() <= maskedAddress); assert(dmi_data.get_end_address() >= maskedAddress); } // Should always succeed sc_dt::uint64 start, end; start = dmi_data.get_start_address(); end = dmi_data.get_end_address(); limitRange(portId, start, end); dmi_data.set_start_address(start); dmi_data.set_end_address(end); return result; } void invalidateDMIPointers(int portId, sc_dt::uint64 start_range, sc_dt::uint64 end_range) { // FIXME: probably faster to always invalidate everything? if ((portId >= 0) && !limitRange(portId, start_range, end_range)) { // Range does not fall into address range of target return; } for (unsigned int i = 0; i < NR_OF_INITIATORS; ++i) { (target_socket[i])->invalidate_direct_mem_ptr(start_range, end_range); } } private: void addPendingTransaction(transaction_type& trans, initiator_socket_type* to, int initiatorId) { const ConnectionInfo info = { &target_socket[initiatorId], to }; assert(mPendingTransactions.find(&trans) == mPendingTransactions.end()); mPendingTransactions[&trans] = info; } private: struct ConnectionInfo { target_socket_type* from; initiator_socket_type* to; }; typedef std::map<transaction_type*, ConnectionInfo> PendingTransactions; typedef typename PendingTransactions::iterator PendingTransactionsIterator; typedef typename PendingTransactions::const_iterator PendingTransactionsConstIterator; private: PendingTransactions mPendingTransactions; tlm_utils::peq_with_get<transaction_type> mRequestPEQ; sc_core::sc_event mBeginRequestEvent; sc_core::sc_event mEndRequestEvent; tlm_utils::peq_with_get<transaction_type> mResponsePEQ; sc_core::sc_event mBeginResponseEvent; sc_core::sc_event mEndResponseEvent; }; #endif
at_target_1_phase目标模块的构成
at_target_1_phase类的主要子模块成员是一个socket，并且该类继承了一个fw接口：
class at_target_1_phase : public sc_core::sc_module , virtual public tlm::tlm_fw_transport_if<> {
public: typedef tlm::tlm_generic_payload *gp_ptr; tlm::tlm_target_socket<> m_memory_socket;
给图：
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2.从构造函数看模块连接关系
从initiator_top类的构造函数可以看出来，
//===================================================================== /// @file initiator_top.cpp // /// @brief Implements instantiation and interconnect of traffic_generator /// and an initiator via sc_fifos for at_1_phase_example // //===================================================================== // Original Authors: // Bill Bunton, ESLX // Charles Wilson, ESLX // Anna Keist, ESLX // Jack Donovan, ESLX //===================================================================== #include "initiator_top.h" // Top traffic generator & initiator #include "reporting.h" // reporting macro helpers static const char *filename = "initiator_top.cpp"; ///< filename for reporting /// Constructor initiator_top::initiator_top ( sc_core::sc_module_name name , const unsigned int ID , sc_dt::uint64 base_address_1 , sc_dt::uint64 base_address_2 , unsigned int active_txn_count ) :sc_module (name) // module name for top ,initiator_socket ("at_initiator_socket") // TLM socket ,m_ID (ID) // initiator ID ,m_initiator // Init initiator ("m_initiator_1_phase" ,ID ,sc_core::sc_time(7, sc_core::SC_NS) // set initiator end rsp delay ) ,m_traffic_gen // Init traffic Generator //LL::本例中系统生成了两个 ("m_traffic_gen" ,ID ,base_address_1 // first base address ,base_address_2 // second base address ,active_txn_count // Max active transactions ) {//LL::通过initiator_top::m_request_fifo 把其两个成员traffic_gen和select_initiator的两个sc_port连接起来。 /// Bind ports to m_request_fifo between m_initiator and m_traffic_gen m_traffic_gen.request_out_port (m_request_fifo); m_initiator.request_in_port (m_request_fifo); /// Bind ports to m_response_fifo between m_initiator and m_traffic_gen m_initiator.response_out_port (m_response_fifo); m_traffic_gen.response_in_port (m_response_fifo); /// Bind initiator-socket to initiator-socket hierarchical connection m_initiator.initiator_socket(initiator_socket); } //===================================================================== /// @fn initiator_top::invalidate_direct_mem_ptr /// /// @brief Unused mandatory virtual implementation /// /// @details /// No DMI is implemented in this example so unused /// //===================================================================== void initiator_top::invalidate_direct_mem_ptr ( sc_dt::uint64 start_range ,sc_dt::uint64 end_range ) { std::ostringstream msg; // log message msg.str (""); msg << "Initiator: " << m_ID << " Not implemented"; REPORT_ERROR(filename, __FUNCTION__, msg.str()); } // end invalidate_direct_mem_ptr //===================================================================== /// @fn initiator_top::nb_transport_bw // /// @brief Unused mandatory virtual implementation /// /// @details /// Unused implementation from hierarchichal connectivity of /// Initiator sockets. /// //===================================================================== tlm::tlm_sync_enum initiator_top::nb_transport_bw ( tlm::tlm_generic_payload &payload ,tlm::tlm_phase &phase ,sc_core::sc_time &delta ) { std::ostringstream msg; // log message msg.str (""); msg << "Initiator: " << m_ID << " Not implemented, for hierachical connection of initiator socket"; REPORT_ERROR(filename, __FUNCTION__, msg.str()); return tlm::TLM_COMPLETED; } // end nb_transport_bw其中端口 request_in_port和response_out_port 主要用来与initiator_top内部里一个类traffic_generator进行连接。
initiator_socket则是用来与更高层的initiator_top的socket绑定，把从request_in_port中读来的数据发送出去，或接收从更高层的socket发来的数据传递给response_out_port , 高层
