文件：
src/tlm1/uvm_port_base.svh
类：
uvm_port_base
uvm_port_component_base派生自uvm_component，因此具有其所有特性。提供了一下接口，get_connected_to 用于返回所有的port主动连接端口。get_provided_to 用于被动连接的接口。is_port, is_export, is_imp这三个接口用于判断是否是一个PORT，EXPORT和IMP。这几个接口都是纯虚类，没有任何实质内容。它重载了build_phase, 没有调用supr.build_phase,从而把自动config给关了。在uvm_port_component实现了uvm_port_component_base的方法。其中最重要的是PORT m_port 这个变量。
//------------------------------------------------------------------------------ // // CLASS: uvm_port_component_base // //------------------------------------------------------------------------------ // This class defines an interface for obtaining a port's connectivity lists // after or during the end_of_elaboration phase. The sub-class, // <uvm_port_component #(PORT)>, implements this interface. // // The connectivity lists are returned in the form of handles to objects of this // type. This allowing traversal of any port's fan-out and fan-in network // through recursive calls to <get_connected_to> and <get_provided_to>. Each // port's full name and type name can be retrieved using ~get_full_name~ and // ~get_type_name~ methods inherited from <uvm_component>. //------------------------------------------------------------------------------ virtual class uvm_port_component_base extends uvm_component; function new (string name, uvm_component parent); super.new(name,parent); endfunction // Function: get_connected_to // // For a port or export type, this function fills ~list~ with all // of the ports, exports and implementations that this port is // connected to. pure virtual function void get_connected_to(ref uvm_port_list list); // Function: get_provided_to // // For an implementation or export type, this function fills ~list~ with all // of the ports, exports and implementations that this port is // provides its implementation to. pure virtual function void get_provided_to(ref uvm_port_list list); // Function: is_port // pure virtual function bit is_port(); // Function: is_export // pure virtual function bit is_export(); // Function: is_imp // // These function determine the type of port. The functions are // mutually exclusive; one will return 1 and the other two will // return 0. pure virtual function bit is_imp(); // Turn off auto config by not calling build_phase() virtual function void build_phase(uvm_phase phase); build(); //for backward compat return; endfunction virtual task do_task_phase (uvm_phase phase); endtask endclass //------------------------------------------------------------------------------ // // CLASS: uvm_port_component #(PORT) // //------------------------------------------------------------------------------ // See description of <uvm_port_component_base> for information about this class //------------------------------------------------------------------------------ class uvm_port_component #(type PORT=uvm_object) extends uvm_port_component_base; PORT m_port; function new (string name, uvm_component parent, PORT port); super.new(name,parent); if (port == null) uvm_report_fatal("Bad usage", "Null handle to port", UVM_NONE); m_port = port; endfunction virtual function string get_type_name(); if(m_port == null) return "uvm_port_component"; return m_port.get_type_name(); endfunction virtual function void resolve_bindings(); m_port.resolve_bindings(); endfunction // Function: get_port // // Retrieve the actual port object that this proxy refers to. function PORT get_port(); return m_port; endfunction virtual function void get_connected_to(ref uvm_port_list list); m_port.get_connected_to(list); endfunction virtual function void get_provided_to(ref uvm_port_list list); m_port.get_provided_to(list); endfunction endfunction function bit is_imp (); return m_port.is_imp(); endfunction endclass function bit is_port (); return m_port.is_port(); endfunction function bit is_export (); return m_port.is_export(); endfunction function bit is_imp (); return m_port.is_imp(); endfunction endclass
再来看uvm_port_base 这个类，其中IF是个很有意思的东西，为了让所有port类能派生自uvm_tlm_if_base或者uvm_sqr_if_base。
//------------------------------------------------------------------------------ // // CLASS: uvm_port_base #(IF) // //------------------------------------------------------------------------------ // // Transaction-level communication between components is handled via its ports, // exports, and imps, all of which derive from this class. // // The uvm_port_base extends IF, which is the type of the interface implemented // by derived port, export, or implementation. IF is also a type parameter to // uvm_port_base. // // IF - The interface type implemented by the subtype to this base port // // The UVM provides a complete set of ports, exports, and imps for the OSCI- // standard TLM interfaces. They can be found in the ../src/tlm/ directory. // For the TLM interfaces, the IF parameter is always <uvm_tlm_if_base #(T1,T2)>. // // Just before <uvm_component::end_of_elaboration_phase>, an internal // <uvm_component::resolve_bindings> process occurs, after which each port and // export holds a list of all imps connected to it via hierarchical connections // to other ports and exports. In effect, we are collapsing the port's fanout, // which can span several levels up and down the component hierarchy, into a // single array held local to the port. Once the list is determined, the port's // min and max connection settings can be checked and enforced. // // uvm_port_base possesses the properties of components in that they have a // hierarchical instance path and parent. Because SystemVerilog does not support // multiple inheritance, uvm_port_base cannot extend both the interface it // implements and <uvm_component>. Thus, uvm_port_base contains a local instance // of uvm_component, to which it delegates such commands as get_name, // get_full_name, and get_parent. // //------------------------------------------------------------------------------ virtual class uvm_port_base #(type IF=uvm_void) extends IF; typedef uvm_port_base #(IF) this_type; // local, protected, and non-user properties protected int unsigned m_if_mask; protected this_type m_if; // REMOVE protected int unsigned m_def_index; uvm_port_component #(this_type) m_comp; local this_type m_provided_by[string]; local this_type m_provided_to[string]; local uvm_port_type_e m_port_type; local int m_min_size; local int m_max_size; local bit m_resolved; local this_type m_imp_list[string]; // Function: new // // The first two arguments are the normal <uvm_component> constructor // arguments. // // The ~port_type~ can be one of <UVM_PORT>, <UVM_EXPORT>, or // <UVM_IMPLEMENTATION>. // // The ~min_size~ and ~max_size~ specify the minimum and maximum number of // implementation (imp) ports that must be connected to this port base by the // end of elaboration. Setting ~max_size~ to ~UVM_UNBOUNDED_CONNECTIONS~ sets no // maximum, i.e., an unlimited number of connections are allowed. // // By default, the parent/child relationship of any port being connected to // this port is not checked. This can be overridden by configuring the // port's ~check_connection_relationships~ bit via ~uvm_config_int::set()~. See // <connect> for more information. function new (string name, uvm_component parent, uvm_port_type_e port_type, int min_size=0, int max_size=1); uvm_component comp; int tmp; m_port_type = port_type; m_min_size = min_size; m_max_size = max_size; m_comp = new(name, parent, this); if (!uvm_config_int::get(m_comp, "", "check_connection_relationships",tmp)) m_comp.set_report_id_action(s_connection_warning_id, UVM_NO_ACTION); endfunction // Function: get_name // // Returns the leaf name of this port. function string get_name(); return m_comp.get_name(); endfunction // Function: get_full_name // // Returns the full hierarchical name of this port. virtual function string get_full_name(); return m_comp.get_full_name(); endfunction // Function: get_parent // // Returns the handle to this port's parent, or ~null~ if it has no parent. virtual function uvm_component get_parent(); return m_comp.get_parent(); endfunction // Function: get_comp // // Returns a handle to the internal proxy component representing this port. // // Ports are considered components. However, they do not inherit // <uvm_component>. Instead, they contain an instance of // <uvm_port_component #(PORT)> that serves as a proxy to this port. virtual function uvm_port_component_base get_comp(); return m_comp; endfunction // Function: get_type_name // // Returns the type name to this port. Derived port classes must implement // this method to return the concrete type. Otherwise, only a generic // "uvm_port", "uvm_export" or "uvm_implementation" is returned. virtual function string get_type_name(); case( m_port_type ) UVM_PORT : return "port"; UVM_EXPORT : return "export"; UVM_IMPLEMENTATION : return "implementation"; endcase endfunction // Function: min_size // // Returns the minimum number of implementation ports that must // be connected to this port by the end_of_elaboration phase. function int max_size (); return m_max_size; endfunction // Function: max_size // // Returns the maximum number of implementation ports that must // be connected to this port by the end_of_elaboration phase. function int min_size (); return m_min_size; endfunction // Function: is_unbounded // // Returns 1 if this port has no maximum on the number of implementation // ports this port can connect to. A port is unbounded when the ~max_size~ // argument in the constructor is specified as ~UVM_UNBOUNDED_CONNECTIONS~. function bit is_unbounded (); return (m_max_size == UVM_UNBOUNDED_CONNECTIONS); endfunction // Function: is_port function bit is_port (); return m_port_type == UVM_PORT; endfunction // Function: is_export function bit is_export (); return m_port_type == UVM_EXPORT; endfunction // Function: is_imp // // Returns 1 if this port is of the type given by the method name, // 0 otherwise. function bit is_imp (); return m_port_type == UVM_IMPLEMENTATION; endfunction // Function: size // // Gets the number of implementation ports connected to this port. The value // is not valid before the end_of_elaboration phase, as port connections have // not yet been resolved. function int size (); return m_imp_list.num(); endfunction function void set_if (int index=0); m_if = get_if(index); if (m_if != null) m_def_index = index; endfunction function int m_get_if_mask(); return m_if_mask; endfunction // Function: set_default_index // // Sets the default implementation port to use when calling an interface // method. This method should only be called on UVM_EXPORT types. The value // must not be set before the end_of_elaboration phase, when port connections // have not yet been resolved. function void set_default_index (int index); m_def_index = index; endfunction // Function: connect // // Connects this port to the given ~provider~ port. The ports must be // compatible in the following ways // // - Their type parameters must match // // - The ~provider~'s interface type (blocking, non-blocking, analysis, etc.) // must be compatible. Each port has an interface mask that encodes the // interface(s) it supports. If the bitwise AND of these masks is equal to // the this port's mask, the requirement is met and the ports are // compatible. For example, a uvm_blocking_put_port #(T) is compatible with // a uvm_put_export #(T) and uvm_blocking_put_imp #(T) because the export // and imp provide the interface required by the uvm_blocking_put_port. // // - Ports of type <UVM_EXPORT> can only connect to other exports or imps. // // - Ports of type <UVM_IMPLEMENTATION> cannot be connected, as they are // bound to the component that implements the interface at time of // construction. // // In addition to type-compatibility checks, the relationship between this // port and the ~provider~ port will also be checked if the port's // ~check_connection_relationships~ configuration has been set. (See <new> // for more information.) // // Relationships, when enabled, are checked are as follows: // // - If this port is a UVM_PORT type, the ~provider~ can be a parent port, // or a sibling export or implementation port. // // - If this port is a <UVM_EXPORT> type, the provider can be a child // export or implementation port. // // If any relationship check is violated, a warning is issued. // // Note- the <uvm_component::connect_phase> method is related to but not the same // as this method. The component's ~connect~ method is a phase callback where // port's ~connect~ method calls are made. virtual function void connect (this_type provider); uvm_root top; uvm_coreservice_t cs; cs = uvm_coreservice_t::get(); top = cs.get_root(); if (end_of_elaboration_ph.get_state() == UVM_PHASE_EXECUTING || // TBD tidy end_of_elaboration_ph.get_state() == UVM_PHASE_DONE ) begin m_comp.uvm_report_warning("Late Connection", {"Attempt to connect ",this.get_full_name()," (of type ",this.get_type_name(), ") at or after end_of_elaboration phase. Ignoring."}); return; end if (provider == null) begin m_comp.uvm_report_error(s_connection_error_id, "Cannot connect to null port handle", UVM_NONE); return; end if (provider == this) begin m_comp.uvm_report_error(s_connection_error_id, "Cannot connect a port instance to itself", UVM_NONE); return; end if ((provider.m_if_mask & m_if_mask) != m_if_mask) begin m_comp.uvm_report_error(s_connection_error_id, {provider.get_full_name(), " (of type ",provider.get_type_name(), ") does not provide the complete interface required of this port (type ", get_type_name(),")"}, UVM_NONE); return; end // IMP.connect(anything) is illegal if (is_imp()) begin m_comp.uvm_report_error(s_connection_error_id, $sformatf( "Cannot call an imp port's connect method. An imp is connected only to the component passed in its constructor. (You attempted to bind this imp to %s)", provider.get_full_name()), UVM_NONE); return; end // EXPORT.connect(PORT) are illegal if (is_export() && provider.is_port()) begin m_comp.uvm_report_error(s_connection_error_id, $sformatf( "Cannot connect exports to ports Try calling port.connect(export) instead. (You attempted to bind this export to %s).", provider.get_full_name()), UVM_NONE); return; end void'(m_check_relationship(provider)); m_provided_by[provider.get_full_name()] = provider; provider.m_provided_to[get_full_name()] = this; endfunction // Function: debug_connected_to // // The ~debug_connected_to~ method outputs a visual text display of the // port/export/imp network to which this port connects (i.e., the port's // fanout). // // This method must not be called before the end_of_elaboration phase, as port // connections are not resolved until then. function void debug_connected_to (int level=0, int max_level=-1); int sz, num, curr_num; string s_sz; static string indent, save; this_type port; if (level < 0) level = 0; if (level == 0) begin save = ""; indent=" "; end if (max_level != -1 && level >= max_level) return; num = m_provided_by.num(); if (m_provided_by.num() != 0) begin foreach (m_provided_by[nm]) begin curr_num++; port = m_provided_by[nm]; save = {save, indent, " | "}; save = {save, indent, " |_",nm," (",port.get_type_name(),") "}; indent = (num > 1 && curr_num != num) ? {indent," | "}:{indent, " "}; port.debug_connected_to(level+1, max_level); indent = indent.substr(0,indent.len()-4-1); end end if (level == 0) begin if (save != "") save = {"This port's fanout network: ", get_full_name()," (",get_type_name(),") ",save," "}; if (m_imp_list.num() == 0) begin uvm_root top; uvm_coreservice_t cs; cs = uvm_coreservice_t::get(); top = cs.get_root(); if (end_of_elaboration_ph.get_state() == UVM_PHASE_EXECUTING || end_of_elaboration_ph.get_state() == UVM_PHASE_DONE ) // TBD tidy save = {save," Connected implementations: none "}; else save = {save, " Connected implementations: not resolved until end-of-elab "}; end else begin save = {save," Resolved implementation list: "}; foreach (m_imp_list[nm]) begin port = m_imp_list[nm]; s_sz.itoa(sz); save = {save, indent, s_sz, ": ",nm," (",port.get_type_name(),") "}; sz++; end end m_comp.uvm_report_info("debug_connected_to", save); end endfunction // Function: debug_provided_to // // The ~debug_provided_to~ method outputs a visual display of the port/export // network that ultimately connect to this port (i.e., the port's fanin). // // This method must not be called before the end_of_elaboration phase, as port // connections are not resolved until then. function void debug_provided_to (int level=0, int max_level=-1); string nm; int num,curr_num; this_type port; static string indent, save; if (level < 0) level = 0; if (level == 0) begin save = ""; indent = " "; end if (max_level != -1 && level > max_level) return; num = m_provided_to.num(); if (num != 0) begin foreach (m_provided_to[nm]) begin curr_num++; port = m_provided_to[nm]; save = {save, indent, " | "}; save = {save, indent, " |_",nm," (",port.get_type_name(),") "}; indent = (num > 1 && curr_num != num) ? {indent," | "}:{indent, " "}; port.debug_provided_to(level+1, max_level); indent = indent.substr(0,indent.len()-4-1); end end if (level == 0) begin if (save != "") save = {"This port's fanin network: ", get_full_name()," (",get_type_name(),") ",save," "}; if (m_provided_to.num() == 0) save = {save,indent,"This port has not been bound "}; m_comp.uvm_report_info("debug_provided_to", save); end endfunction // get_connected_to // ---------------- function void get_connected_to (ref uvm_port_list list); this_type port; list.delete(); foreach (m_provided_by[name]) begin port = m_provided_by[name]; list[name] = port.get_comp(); end endfunction // get_provided_to // --------------- function void get_provided_to (ref uvm_port_list list); this_type port; list.delete(); foreach (m_provided_to[name]) begin port = m_provided_to[name]; list[name] = port.get_comp(); end endfunction // m_check_relationship // -------------------- local function bit m_check_relationship (this_type provider); string s; this_type from; uvm_component from_parent; uvm_component to_parent; uvm_component from_gparent; uvm_component to_gparent; // Checks that the connection is between ports that are hierarchically // adjacent (up or down one level max, or are siblings), // and check for legal direction, requirer.connect(provider). // if we're an analysis port, allow connection to anywhere if (get_type_name() == "uvm_analysis_port") return 1; from = this; from_parent = get_parent(); to_parent = provider.get_parent(); // skip check if we have a parentless port if (from_parent == null || to_parent == null) return 1; from_gparent = from_parent.get_parent(); to_gparent = to_parent.get_parent(); // Connecting port-to-port: CHILD.port.connect(PARENT.port) // if (from.is_port() && provider.is_port() && from_gparent != to_parent) begin s = {provider.get_full_name(), " (of type ",provider.get_type_name(), ") is not up one level of hierarchy from this port. ", "A port-to-port connection takes the form ", "child_component.child_port.connect(parent_port)"}; m_comp.uvm_report_warning(s_connection_warning_id, s, UVM_NONE); return 0; end // Connecting port-to-export: SIBLING.port.connect(SIBLING.export) // Connecting port-to-imp: SIBLING.port.connect(SIBLING.imp) // else if (from.is_port() && (provider.is_export() || provider.is_imp()) && from_gparent != to_gparent) begin s = {provider.get_full_name(), " (of type ",provider.get_type_name(), ") is not at the same level of hierarchy as this port. ", "A port-to-export connection takes the form ", "component1.port.connect(component2.export)"}; m_comp.uvm_report_warning(s_connection_warning_id, s, UVM_NONE); return 0; end // Connecting export-to-export: PARENT.export.connect(CHILD.export) // Connecting export-to-imp: PARENT.export.connect(CHILD.imp) // else if (from.is_export() && (provider.is_export() || provider.is_imp()) && from_parent != to_gparent) begin s = {provider.get_full_name(), " (of type ",provider.get_type_name(), ") is not down one level of hierarchy from this export. ", "An export-to-export or export-to-imp connection takes the form ", "parent_export.connect(child_component.child_export)"}; m_comp.uvm_report_warning(s_connection_warning_id, s, UVM_NONE); return 0; end return 1; endfunction // m_add_list // // Internal method. local function void m_add_list (this_type provider); string sz; this_type imp; for (int i = 0; i < provider.size(); i++) begin imp = provider.get_if(i); if (!m_imp_list.exists(imp.get_full_name())) m_imp_list[imp.get_full_name()] = imp; end endfunction // Function: resolve_bindings // // This callback is called just before entering the end_of_elaboration phase. // It recurses through each port's fanout to determine all the imp // destinations. It then checks against the required min and max connections. // After resolution, <size> returns a valid value and <get_if> // can be used to access a particular imp. // // This method is automatically called just before the start of the // end_of_elaboration phase. Users should not need to call it directly. virtual function void resolve_bindings(); if (m_resolved) // don't repeat ourselves return; if (is_imp()) begin m_imp_list[get_full_name()] = this; end else begin foreach (m_provided_by[nm]) begin this_type port; port = m_provided_by[nm]; port.resolve_bindings(); m_add_list(port); end end m_resolved = 1; if (size() < min_size() ) begin m_comp.uvm_report_error(s_connection_error_id, $sformatf("connection count of %0d does not meet required minimum of %0d", size(), min_size()), UVM_NONE); end if (max_size() != UVM_UNBOUNDED_CONNECTIONS && size() > max_size() ) begin m_comp.uvm_report_error(s_connection_error_id, $sformatf("connection count of %0d exceeds maximum of %0d", size(), max_size()), UVM_NONE); end if (size()) set_if(0); endfunction // Function: get_if // // Returns the implementation (imp) port at the given index from the array of // imps this port is connected to. Use <size> to get the valid range for index. // This method can only be called at the end_of_elaboration phase or after, as // port connections are not resolved before then. function uvm_port_base #(IF) get_if(int index=0); string s; if (size()==0) begin m_comp.uvm_report_warning("get_if", "Port size is zero; cannot get interface at any index", UVM_NONE); return null; end if (index < 0 || index >= size()) begin $sformat(s, "Index %0d out of range [0,%0d]", index, size()-1); m_comp.uvm_report_warning(s_connection_error_id, s, UVM_NONE); return null; end foreach (m_imp_list[nm]) begin if (index == 0) return m_imp_list[nm]; index--; end endfunction endclass