//
//-----------------------------------------------------------------------------
// Copyright 2007-2011 Mentor Graphics Corporation
// Copyright 2007-2011 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 uvm_event;
typedef class uvm_event_pool;
typedef class uvm_component;
//------------------------------------------------------------------------------
//
// CLASS: uvm_transaction
//
// The uvm_transaction class is the root base class for UVM transactions.
// Inheriting all the methods of uvm_object, uvm_transaction adds a timing and
// recording interface.
//
// This class provides timestamp properties, notification events, and transaction
// recording support.
//
// Use of this class as a base for user-defined transactions
// is deprecated. Its subtype, <uvm_sequence_item>, shall be used as the
// base class for all user-defined transaction types.
//
// The intended use of this API is via a <uvm_driver> to call <uvm_component::accept_tr>,
// <uvm_component::begin_tr>, and <uvm_component::end_tr> during the course of
// sequence item execution. These methods in the component base class will
// call into the corresponding methods in this class to set the corresponding
// timestamps (accept_time, begin_time, and end_tr), trigger the
// corresponding event (<begin_event> and <end_event>, and, if enabled,
// record the transaction contents to a vendor-specific transaction database.
//
// Note that start_item/finish_item (or `uvm_do* macro) executed from a
// <uvm_sequence #(REQ,RSP)> will automatically trigger
// the begin_event and end_events via calls to begin_tr and end_tr. While
// convenient, it is generally the responsibility of drivers to mark a
// transaction's progress during execution. To allow the driver to control
// sequence item timestamps, events, and recording, you must add
// +define+UVM_DISABLE_AUTO_ITEM_RECORDING when compiling the UVM package.
// Alternatively, users may use the transaction's event pool, <events>,
// to define custom events for the driver to trigger and the sequences to wait on. Any
// in-between events such as marking the begining of the address and data
// phases of transaction execution could be implemented via the
// <events> pool.
//
// In pipelined protocols, the driver may release a sequence (return from
// finish_item() or it's `uvm_do macro) before the item has been completed.
// If the driver uses the begin_tr/end_tr API in uvm_component, the sequence can
// wait on the item's <end_event> to block until the item was fully executed,
// as in the following example.
//
//| task uvm_execute(item, ...);
//| // can use the `uvm_do macros as well
//| start_item(item);
//| item.randomize();
//| finish_item(item);
//| item.end_event.wait_on();
//| // get_response(rsp, item.get_transaction_id()); //if needed
//| endtask
//|
//
// A simple two-stage pipeline driver that can execute address and
// data phases concurrently might be implemented as follows:
//
//| task run();
//| // this driver supports a two-deep pipeline
//| fork
//| do_item();
//| do_item();
//| join
//| endtask
//|
//|
//| task do_item();
//|
//| forever begin
//| mbus_item req;
//|
//| lock.get();
//|
//| seq_item_port.get(req); // Completes the sequencer-driver handshake
//|
//| accept_tr(req);
//|
//| // request bus, wait for grant, etc.
//|
//| begin_tr(req);
//|
//| // execute address phase
//|
//| // allows next transaction to begin address phase
//| lock.put();
//|
//| // execute data phase
//| // (may trigger custom "data_phase" event here)
//|
//| end_tr(req);
//|
//| end
//|
//| endtask: do_item
//
//------------------------------------------------------------------------------
virtual class uvm_transaction extends uvm_object;
// Function: new
//
// Creates a new transaction object. The name is the instance name of the
// transaction. If not supplied, then the object is unnamed.
extern function new (string name="", uvm_component initiator=null);
// Function: accept_tr
//
// Calling ~accept_tr~ indicates that the transaction item has been received by
// a consumer component. Typically a <uvm_driver> would call <uvm_component::accept_tr>,
// which calls this method-- upon return from a get_next_item(), get(), or peek()
// call on its sequencer port, <uvm_driver::seq_item_port>.
//
// With some
// protocols, the received item may not be started immediately after it is
// accepted. For example, a bus driver, having accepted a request transaction,
// may still have to wait for a bus grant before begining to execute
// the request.
//
// This function performs the following actions:
//
// - The transaction's internal accept time is set to the current simulation
// time, or to accept_time if provided and non-zero. The ~accept_time~ may be
// any time, past or future.
//
// - The transaction's internal accept event is triggered. Any processes
// waiting on the this event will resume in the next delta cycle.
//
// - The <do_accept_tr> method is called to allow for any post-accept
// action in derived classes.
extern function void accept_tr (time accept_time=0);
// Function: do_accept_tr
//
// This user-definable callback is called by <accept_tr> just before the accept
// event is triggered. Implementations should call ~super.do_accept_tr~ to
// ensure correct operation.
extern virtual protected function void do_accept_tr ();
// Function: begin_tr
//
// This function indicates that the transaction has been started and is not
// the child of another transaction. Generally, a consumer component begins
// execution of a transactions it receives.
//
// Typically a <uvm_driver> would call <uvm_component::begin_tr>, which
// calls this method, before actual execution of a sequence item transaction.
// Sequence items received by a driver are always a child of a parent sequence.
// In this case, begin_tr obtains the parent handle and delegates to <begin_child_tr>.
//
// See <accept_tr> for more information on how the
// begin-time might differ from when the transaction item was received.
//
// This function performs the following actions:
//
// - The transaction's internal start time is set to the current simulation
// time, or to begin_time if provided and non-zero. The begin_time may be
// any time, past or future, but should not be less than the accept time.
//
// - If recording is enabled, then a new database-transaction is started with
// the same begin time as above.
//
// - The <do_begin_tr> method is called to allow for any post-begin action in
// derived classes.
//
// - The transaction's internal begin event is triggered. Any processes
// waiting on this event will resume in the next delta cycle.
//
// The return value is a transaction handle, which is valid (non-zero) only if
// recording is enabled. The meaning of the handle is implementation specific.
extern function integer begin_tr (time begin_time=0);
// Function: begin_child_tr
//
// This function indicates that the transaction has been started as a child of
// a parent transaction given by ~parent_handle~. Generally, a consumer
// component calls this method via <uvm_component::begin_child_tr> to indicate
// the actual start of execution of this transaction.
//
// The parent handle is obtained by a previous call to begin_tr or
// begin_child_tr. If the parent_handle is invalid (=0), then this function
// behaves the same as <begin_tr>.
//
// This function performs the following actions:
//
// - The transaction's internal start time is set to the current simulation
// time, or to begin_time if provided and non-zero. The begin_time may be
// any time, past or future, but should not be less than the accept time.
//
// - If recording is enabled, then a new database-transaction is started with
// the same begin time as above. The record method inherited from <uvm_object>
// is then called, which records the current property values to this new
// transaction. Finally, the newly started transaction is linked to the
// parent transaction given by parent_handle.
//
// - The <do_begin_tr> method is called to allow for any post-begin
// action in derived classes.
//
// - The transaction's internal begin event is triggered. Any processes
// waiting on this event will resume in the next delta cycle.
//
// The return value is a transaction handle, which is valid (non-zero) only if
// recording is enabled. The meaning of the handle is implementation specific.
extern function integer begin_child_tr (time begin_time=0,
integer parent_handle=0);
// Function: do_begin_tr
//
// This user-definable callback is called by <begin_tr> and <begin_child_tr> just
// before the begin event is triggered. Implementations should call
// ~super.do_begin_tr~ to ensure correct operation.
extern virtual protected function void do_begin_tr ();
// Function: end_tr
//
// This function indicates that the transaction execution has ended.
// Generally, a consumer component ends execution of the transactions it
// receives.
//
// You must have previously called <begin_tr> or <begin_child_tr> for this
// call to be successful.
//
// Typically a <uvm_driver> would call <uvm_component::end_tr>, which
// calls this method, upon completion of a sequence item transaction.
// Sequence items received by a driver are always a child of a parent sequence.
// In this case, begin_tr obtain the parent handle and delegate to <begin_child_tr>.
//
// This function performs the following actions:
//
// - The transaction's internal end time is set to the current simulation
// time, or to ~end_time~ if provided and non-zero. The ~end_time~ may be any
// time, past or future, but should not be less than the begin time.
//
// - If recording is enabled and a database-transaction is currently active,
// then the record method inherited from uvm_object is called, which records
// the final property values. The transaction is then ended. If ~free_handle~
// is set, the transaction is released and can no longer be linked to (if
// supported by the implementation).
//
// - The <do_end_tr> method is called to allow for any post-end
// action in derived classes.
//
// - The transaction's internal end event is triggered. Any processes waiting
// on this event will resume in the next delta cycle.
extern function void end_tr (time end_time=0, bit free_handle=1);
// Function: do_end_tr
//
// This user-definable callback is called by <end_tr> just before the end event
// is triggered. Implementations should call ~super.do_end_tr~ to ensure correct
// operation.
extern virtual protected function void do_end_tr ();
// Function: get_tr_handle
//
// Returns the handle associated with the transaction, as set by a previous
// call to <begin_child_tr> or <begin_tr> with transaction recording enabled.
extern function integer get_tr_handle ();
// Function: disable_recording
//
// Turns off recording for the transaction stream. This method does not
// effect a <uvm_component>'s recording streams.
extern function void disable_recording ();
// Function: enable_recording
//
// Turns on recording to the stream specified by stream, whose interpretation
// is implementation specific. The optional ~recorder~ argument specifies
//
// If transaction recording is on, then a call to record is made when the
// transaction is started and when it is ended.
extern function void enable_recording (string stream, uvm_recorder recorder=null);
// Function: is_recording_enabled
//
// Returns 1 if recording is currently on, 0 otherwise.
extern function bit is_recording_enabled();
// Function: is_active
//
// Returns 1 if the transaction has been started but has not yet been ended.
// Returns 0 if the transaction has not been started.
extern function bit is_active ();
// Function: get_event_pool
//
// Returns the event pool associated with this transaction.
//
// By default, the event pool contains the events: begin, accept, and end.
// Events can also be added by derivative objects. An event pool is a
// specialization of an <uvm_pool #(T)>, e.g. a ~uvm_pool#(uvm_event)~.
extern function uvm_event_pool get_event_pool ();
// Function: set_initiator
//
// Sets initiator as the initiator of this transaction.
//
// The initiator can be the component that produces the transaction. It can
// also be the component that started the transaction. This or any other
// usage is up to the transaction designer.
extern function void set_initiator (uvm_component initiator);
// Function: get_initiator
//
// Returns the component that produced or started the transaction, as set by
// a previous call to set_initiator.
extern function uvm_component get_initiator ();
// Function: get_accept_time
extern function time get_accept_time ();
// Function: get_begin_time
extern function time get_begin_time ();
// Function: get_end_time
//
// Returns the time at which this transaction was accepted, begun, or ended,
// as by a previous call to <accept_tr>, <begin_tr>, <begin_child_tr>, or <end_tr>.
extern function time get_end_time ();
// Function: set_transaction_id
//
// Sets this transaction's numeric identifier to id. If not set via this
// method, the transaction ID defaults to -1.
//
// When using sequences to generate stimulus, the transaction ID is used along
// with the sequence ID to route responses in sequencers and to correlate
// responses to requests.
extern function void set_transaction_id(integer id);
// Function: get_transaction_id
//
// Returns this transaction's numeric identifier, which is -1 if not set
// explicitly by ~set_transaction_id~.
//
// When using a <uvm_sequence #(REQ,RSP)> to generate stimulus, the transaction
// ID is used along
// with the sequence ID to route responses in sequencers and to correlate
// responses to requests.
extern function integer get_transaction_id();
// Variable: events
//
// The event pool instance for this transaction. This pool is used to track
// various The <begin_event>
const uvm_event_pool events = new;
// Variable: begin_event
//
// A <uvm_event> that is triggered when this transaction's actual execution on the
// bus begins, typically as a result of a driver calling <uvm_component::begin_tr>.
// Processes that wait on this event will block until the transaction has
// begun.
//
// For more information, see the general discussion for <uvm_transaction>.
// See <uvm_event> for details on the event API.
//
uvm_event begin_event;
// Variable: end_event
//
// A <uvm_event> that is triggered when this transaction's actual execution on
// the bus ends, typically as a result of a driver calling <uvm_component::end_tr>.
// Processes that wait on this event will block until the transaction has
// ended.
//
// For more information, see the general discussion for <uvm_transaction>.
// See <uvm_event> for details on the event API.
//
//| virtual task my_sequence::body();
//| ...
//| start_item(item); \
//| item.randomize(); } `uvm_do(item)
//| finish_item(item); /
//| // return from finish item does not always mean item is completed
//| item.end_event.wait_on();
//| ...
//
uvm_event end_event;
//----------------------------------------------------------------------------
//
// Internal methods properties; do not use directly
//
//----------------------------------------------------------------------------
//Override data control methods for internal properties
extern virtual function void do_print (uvm_printer printer);
extern virtual function void do_record (uvm_recorder recorder);
extern virtual function void do_copy (uvm_object rhs);
extern protected function integer m_begin_tr (time begin_time=0,
integer parent_handle=0,
bit has_parent=0);
local integer m_transaction_id = -1;
local time begin_time=-1;
local time end_time=-1;
local time accept_time=-1;
local uvm_component initiator;
local integer stream_handle=0;
local integer tr_handle=0;
local bit record_enable;
local uvm_recorder m_recorder;
endclass
//------------------------------------------------------------------------------
// IMPLEMENTATION
//------------------------------------------------------------------------------
// new
// ---
function uvm_transaction::new (string name="",
uvm_component initiator = null);
super.new(name);
this.initiator = initiator;
m_transaction_id = -1;
begin_event = events.get("begin");
end_event = events.get("end");
endfunction // uvm_transaction
// set_transaction_id
function void uvm_transaction::set_transaction_id(integer id);
m_transaction_id = id;
endfunction
// get_transaction_id
function integer uvm_transaction::get_transaction_id();
return (m_transaction_id);
endfunction
// set_initiator
// ------------
function void uvm_transaction::set_initiator(uvm_component initiator);
this.initiator = initiator;
endfunction
// get_initiator
// ------------
function uvm_component uvm_transaction::get_initiator();
return initiator;
endfunction
// get_event_pool
// --------------
function uvm_event_pool uvm_transaction::get_event_pool();
return events;
endfunction
// is_active
// ---------
function bit uvm_transaction::is_active();
return (tr_handle != 0);
endfunction
// get_begin_time
// --------------
function time uvm_transaction::get_begin_time ();
return begin_time;
endfunction
// get_end_time
// ------------
function time uvm_transaction::get_end_time ();
return end_time;
endfunction
// get_accept_time
// ---------------
function time uvm_transaction::get_accept_time ();
return accept_time;
endfunction
// do_accept_tr
// -------------
function void uvm_transaction::do_accept_tr();
return;
endfunction
// do_begin_tr
// ------------
function void uvm_transaction::do_begin_tr();
return;
endfunction
// do_end_tr
// ----------
function void uvm_transaction::do_end_tr();
return;
endfunction
// do_print
// --------
function void uvm_transaction::do_print (uvm_printer printer);
string str;
uvm_component tmp_initiator; //work around $swrite bug
super.do_print(printer);
if(accept_time != -1)
printer.print_time("accept_time", accept_time);
if(begin_time != -1)
printer.print_time("begin_time", begin_time);
if(end_time != -1)
printer.print_time("end_time", end_time);
if(initiator != null) begin
tmp_initiator = initiator;
$swrite(str,"@%0d", tmp_initiator.get_inst_id());
printer.print_generic("initiator", initiator.get_type_name(), -1, str);
end
endfunction
function void uvm_transaction::do_copy (uvm_object rhs);
uvm_transaction txn;
super.do_copy(rhs);
if(rhs == null) return;
if(!$cast(txn, rhs) ) return;
accept_time = txn.accept_time;
begin_time = txn.begin_time;
end_time = txn.end_time;
initiator = txn.initiator;
stream_handle = txn.stream_handle;
tr_handle = txn.tr_handle;
record_enable = txn.record_enable;
endfunction
// do_record
// ---------
function void uvm_transaction::do_record (uvm_recorder recorder);
string s;
super.do_record(recorder);
if(accept_time != -1)
recorder.record_field("accept_time", accept_time, $bits(accept_time), UVM_TIME);
if(initiator != null) begin
uvm_recursion_policy_enum p = recorder.policy;
recorder.policy = UVM_REFERENCE;
recorder.record_object("initiator", initiator);
recorder.policy = p;
end
endfunction
// get_tr_handle
// ---------
function integer uvm_transaction::get_tr_handle ();
return tr_handle;
endfunction
// disable_recording
// -----------------
function void uvm_transaction::disable_recording ();
record_enable = 0;
endfunction
// enable_recording
// ----------------
function void uvm_transaction::enable_recording (string stream, uvm_recorder recorder=null);
string scope;
int lastdot;
for(lastdot=stream.len()-1; lastdot>0; --lastdot)
if(stream[lastdot] == ".") break;
if(lastdot) begin
scope = stream.substr(0, lastdot-1);
stream = stream.substr(lastdot+1, stream.len()-1);
end
if (recorder == null)
recorder = uvm_default_recorder;
m_recorder = recorder;
this.stream_handle = m_recorder.create_stream(stream, "TVM", scope);
record_enable = 1;
endfunction
// is_recording_enabled
// --------------------
function bit uvm_transaction::is_recording_enabled ();
return record_enable;
endfunction
// accept_tr
// ---------
function void uvm_transaction::accept_tr (time accept_time = 0);
uvm_event e;
if(accept_time != 0)
this.accept_time = accept_time;
else
this.accept_time = $realtime;
do_accept_tr();
e = events.get("accept");
if(e!=null)
e.trigger();
endfunction
// begin_tr
// -----------
function integer uvm_transaction::begin_tr (time begin_time=0);
return m_begin_tr(begin_time, 0, 0);
endfunction
// begin_child_tr
// --------------
//Use a parent handle of zero to link to the parent after begin
function integer uvm_transaction::begin_child_tr (time begin_time=0,
integer parent_handle=0);
return m_begin_tr(begin_time, parent_handle, 1);
endfunction
// m_begin_tr
// -----------
function integer uvm_transaction::m_begin_tr (time begin_time=0,
integer parent_handle=0,
bit has_parent=0);
if(begin_time != 0)
this.begin_time = begin_time;
else
this.begin_time = $realtime;
// May want to establish predecessor/successor relation
// (don't free handle until then)
if(record_enable) begin
if(m_recorder.check_handle_kind("Transaction", tr_handle)==1)
end_tr();
if(!has_parent)
tr_handle = m_recorder.begin_tr("Begin_No_Parent, Link",
stream_handle, get_type_name(),"","",this.begin_time);
else begin
tr_handle = m_recorder.begin_tr("Begin_End, Link",
stream_handle, get_type_name(),"","",this.begin_time);
if(parent_handle)
m_recorder.link_tr(parent_handle, tr_handle, "child");
end
m_recorder.tr_handle = tr_handle;
if(m_recorder.check_handle_kind("Transaction", tr_handle)!=1)
$display("tr handle %0d not valid!",tr_handle);
end
else
tr_handle = 0;
do_begin_tr(); //execute callback before event trigger
begin_event.trigger();
return tr_handle;
endfunction
// end_tr
// ------
function void uvm_transaction::end_tr (time end_time=0, bit free_handle=1);
if(end_time != 0)
this.end_time = end_time;
else
this.end_time = $realtime;
do_end_tr(); // Callback prior to actual ending of transaction
if(is_active()) begin
m_recorder.tr_handle = tr_handle;
record(m_recorder);
m_recorder.end_tr(tr_handle,this.end_time);
if(free_handle && m_recorder.check_handle_kind("Transaction", tr_handle)==1)
begin
// once freed, can no longer link to
m_recorder.free_tr(tr_handle);
end
tr_handle = 0;
end
end_event.trigger();
endfunction
uvm_transaction.svh
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