//
//------------------------------------------------------------------------------
// Copyright 2007-2011 Mentor Graphics Corporation
// Copyright 2007-2010 Cadence Design Systems, Inc.
// Copyright 2010 Synopsys, Inc.
// All Rights Reserved Worldwide
//
// Licensed under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of
// the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in
// writing, software distributed under the License is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See
// the License for the specific language governing
// permissions and limitations under the License.
//------------------------------------------------------------------------------
typedef class [docs]uvm_tlm_event;
//------------------------------------------------------------------------------
//
// Title: TLM FIFO Classes
//
// This section defines TLM-based FIFO classes.
//
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
//
// Class: uvm_tlm_fifo#(T)
//
// This class provides storage of transactions between two independently running
// processes. Transactions are put into the FIFO via the ~put_export~.
// transactions are fetched from the FIFO in the order they arrived via the
// ~get_peek_export~. The ~put_export~ and ~get_peek_export~ are inherited from
// the <uvm_tlm_fifo_base #(T)> super class, and the interface methods provided by
// these exports are defined by the <uvm_tlm_if_base #(T1,T2)> class.
//
//------------------------------------------------------------------------------
class [docs]uvm_tlm_fifo #(type T=int) extends uvm_tlm_fifo_base #(T);
const static string type_name = "uvm_tlm_fifo #(T)";
local mailbox #( T ) m;
local int m_size;
protected int m_pending_blocked_gets;
// Function: new
//
// The ~name~ and ~parent~ are the normal uvm_component constructor arguments.
// The ~parent~ should be ~null~ if the <uvm_tlm_fifo#(T)> is going to be used in a
// statically elaborated construct (e.g., a module). The ~size~ indicates the
// maximum size of the FIFO; a value of zero indicates no upper bound.
function [docs]new(string name, uvm_component parent = null, int size = 1);
super.new(name, parent);
m = new( size );
m_size = size;
endfunction
virtual function string [docs]get_type_name();
return type_name;
endfunction
// Function: size
//
// Returns the capacity of the FIFO-- that is, the number of entries
// the FIFO is capable of holding. A return value of 0 indicates the
// FIFO capacity has no limit.
virtual function int [docs]size();
return m_size;
endfunction
// Function: used
//
// Returns the number of entries put into the FIFO.
virtual function int [docs]used();
return m.num();
endfunction
// Function: is_empty
//
// Returns 1 when there are no entries in the FIFO, 0 otherwise.
virtual function bit [docs]is_empty();
return (m.num() == 0);
endfunction
// Function: is_full
//
// Returns 1 when the number of entries in the FIFO is equal to its <size>,
// 0 otherwise.
virtual function bit [docs]is_full();
return (m_size != 0) && (m.num() == m_size);
endfunction
virtual task [docs]put( input T t );
m.put( t );
put_ap.write( t );
endtask
virtual task [docs]get( output T t );
m_pending_blocked_gets++;
m.get( t );
m_pending_blocked_gets--;
get_ap.write( t );
endtask
virtual task [docs]peek( output T t );
m.peek( t );
endtask
virtual function bit [docs]try_get( output T t );
if( !m.try_get( t ) ) begin
return 0;
end
get_ap.write( t );
return 1;
endfunction
virtual function bit [docs]try_peek( output T t );
if( !m.try_peek( t ) ) begin
return 0;
end
return 1;
endfunction
virtual function bit [docs]try_put( input T t );
if( !m.try_put( t ) ) begin
return 0;
end
put_ap.write( t );
return 1;
endfunction
virtual function bit [docs]can_put();
return m_size == 0 || m.num() < m_size;
endfunction
virtual function bit [docs]can_get();
return m.num() > 0 && m_pending_blocked_gets == 0;
endfunction
virtual function bit [docs]can_peek();
return m.num() > 0;
endfunction
// Function: flush
//
// Removes all entries from the FIFO, after which <used> returns 0
// and <is_empty> returns 1.
virtual function void [docs]flush();
T t;
bit r;
r = 1;
while( r ) r = try_get( t ) ;
if( m.num() > 0 && m_pending_blocked_gets != 0 ) begin
uvm_report_error("flush failed" ,
"there are blocked gets preventing the flush", UVM_NONE);
end
endfunction
endclass
//------------------------------------------------------------------------------
//
// Class: uvm_tlm_analysis_fifo#(T)
//
// An analysis_fifo is a <uvm_tlm_fifo#(T)> with an unbounded size and a write interface.
// It can be used any place a <uvm_analysis_imp> is used. Typical usage is
// as a buffer between a <uvm_analysis_port> in an initiator component
// and TLM1 target component.
//
//------------------------------------------------------------------------------
class [docs]uvm_tlm_analysis_fifo #(type T = int) extends uvm_tlm_fifo #(T);
// Port: analysis_export #(T)
//
// The analysis_export provides the write method to all connected analysis
// ports and parent exports:
//
//| function void write (T t)
//
// Access via ports bound to this export is the normal mechanism for writing
// to an analysis FIFO.
// See write method of <uvm_tlm_if_base #(T1,T2)> for more information.
uvm_analysis_imp #(T, uvm_tlm_analysis_fifo #(T)) analysis_export;
// Function: new
//
// This is the standard uvm_component constructor. ~name~ is the local name
// of this component. The ~parent~ should be left unspecified when this
// component is instantiated in statically elaborated constructs and must be
// specified when this component is a child of another UVM component.
function [docs]new(string name , uvm_component parent = null);
super.new(name, parent, 0); // analysis fifo must be unbounded
analysis_export = new("analysis_export", this);
endfunction
const static string type_name = "uvm_tlm_analysis_fifo #(T)";
virtual function string [docs]get_type_name();
return type_name;
endfunction
function void [docs]write(input T t);
void'(this.try_put(t)); // unbounded => must succeed
endfunction
endclass