#
#-----------------------------------------------------------------------------
# Copyright 2007-2011 Mentor Graphics Corporation
# Copyright 2007-2011 Cadence Design Systems, Inc.
# Copyright 2010 Synopsys, Inc.
# Copyright 2019 Tuomas Poikela
# 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.
#-----------------------------------------------------------------------------
from .sv import sv
from .uvm_recorder import UVMRecorder
from .uvm_object import UVMObject
from .uvm_pool import UVMEventPool
[docs]class UVMTransaction(UVMObject):
"""
The `UVMTransaction` class is the root base class for UVM transactions.
Inheriting all the methods of `UVMObject`, `UVMTransaction` 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 `accept_tr`,
`begin_tr`, and `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_time`), trigger the
corresponding event (`begin_event` and `end_event`, and, if enabled,
record the transaction contents to a vendor-specific transaction database.
Note that get_next_item/item_done when called on a `uvm_seq_item_pull_port`
will automatically trigger the `begin_event` and `end_event` 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 or layering sequence
to control sequence item timestamps, events, and recording, you must call
`UVM_SEQ_ITEM_PULL_IMP.disable_auto_item_recording` at the beginning
of the driver's `run_phase` task.
Users may also 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 beginning 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 `UVMComponent`, the sequence can
wait on the item's `end_event` to block until the item was fully executed,
as in the following example.
.. code-block:: systemverilog
task uvm_execute(item, ...)
// can use the `uvm_do macros as well
start_item(item)
item.randomize()
finish_item(item)
item.self.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:
.. code-block:: systemverilog
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
"""
# // Variable: events
# //
# // The event pool instance for this transaction. This pool is used to track
# // various milestones: by default, begin, accept, and end
#
# const uvm_event_pool events = new
#
#
# // Variable: self.begin_event
# //
# // A ~uvm_event#(uvm_object)~ 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#(T)> for details on the event API.
# //
# uvm_event#(uvm_object) self.begin_event
#
# // Variable: self.end_event
# //
# // A ~uvm_event#(uvm_object)~ 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#(T)> 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.self.end_event.wait_on()
# //| ...
# //
# uvm_event#(uvm_object) self.end_event
# Function: new
#
# Creates a new transaction object. The name is the instance name of the
# transaction. If not supplied, then the object is unnamed.
#
def __init__(self, name="", initiator=None):
UVMObject.__init__(self, name)
self.initiator = initiator
self.m_transaction_id = -1
self.events = UVMEventPool()
self.begin_event = self.events.get("begin")
self.end_event = self.events.get("end")
self.stream_handle = None # For recording
self.tr_recorder = None
self.begin_time = -1
self.end_time = -1
self.accept_time = -1
# // Function: accept_tr
# //
# // Calling ~accept_tr~ indicates that the transaction item has been received by
# // a consumer component. Typically a <uvm_driver #(REQ,RSP)> 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#(REQ,RSP)::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 beginning 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)
[docs] def accept_tr(self, accept_time=0):
e = None
if accept_time != 0:
self.accept_time = accept_time
else:
self.accept_time = sv.realtime()
self.do_accept_tr()
e = self.events.get("accept")
if e is not None:
e.trigger()
# // 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 ()
[docs] def do_accept_tr(self):
return
#
# // 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 #(REQ,RSP)> 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)
[docs] def begin_tr(self, begin_time=0):
return self.m_begin_tr(begin_time)
#
# // 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 inherited <uvm_object::record> method
# // 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)
#Use a parent handle of zero to link to the parent after begin
[docs] def begin_child_tr(self, begin_time=0, parent_handle=0):
return self.m_begin_tr(begin_time, parent_handle)
#
#
# // 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 ()
[docs] def do_begin_tr(self):
pass
# // 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 #(REQ,RSP)> 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)
[docs] def end_tr(self, end_time=0, free_handle=1):
self.end_time = end_time
if end_time == 0:
self.end_time = sv.realtime()
self.do_end_tr() # Callback prior to actual ending of transaction
if(self.is_recording_enabled() and (self.tr_recorder is not None)):
self.record(self.tr_recorder)
self.tr_recorder.close(self.end_time)
if free_handle:
# once freed, can no longer link to
self.tr_recorder.free()
self.tr_recorder = None
self.end_event.trigger()
# // 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 ()
[docs] def do_end_tr(self):
return
# // 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 ()
[docs] def get_tr_handle (self):
if self.tr_recorder is not None:
return self.tr_recorder.get_handle()
else:
return 0
# // Function: disable_recording
# //
# // Turns off recording for the transaction stream. This method does not
# // effect a <uvm_component>'s recording streams.
[docs] def disable_recording(self):
self.stream_handle = None
# // Function: enable_recording
# // Turns on recording to the ~stream~ specified.
# //
# // If transaction recording is on, then a call to ~record~ is made when the
# // transaction is ended.
[docs] def enable_recording(self, stream):
self.stream_handle = stream
# // Function: is_recording_enabled
# //
# // Returns 1 if recording is currently on, 0 otherwise.
#
# extern function bit is_recording_enabled()
[docs] def is_recording_enabled(self):
return self.stream_handle is not None
# // 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 ()
[docs] def is_active(self):
return self.end_time == -1
# // 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 <uvm_pool#(KEY,T)>, e.g. a ~uvm_pool#(uvm_event)~.
#
# extern function uvm_event_pool get_event_pool ()
[docs] def get_event_pool(self):
return self.events
# // 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)
[docs] def set_initiator(self, initiator):
self.initiator = 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
#
[docs] def get_accept_time(self):
return self.accept_time
# // Function: get_begin_time
#
[docs] def get_begin_time(self):
return self.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 ()
[docs] def get_end_time(self):
return self.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.
[docs] def set_transaction_id(self, id):
self.m_transaction_id = 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.
[docs] def get_transaction_id(self):
return self.m_transaction_id
# //----------------------------------------------------------------------------
# //
# // 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)
[docs] def m_begin_tr(self, begin_time=0, parent_handle=0):
m_begin_tr = 0
tmp_time = begin_time
if begin_time == 0:
tmp_time = sv.realtime()
parent_recorder = None
if parent_handle != 0:
parent_recorder = UVMRecorder.get_recorder_from_handle(parent_handle)
# If we haven't ended the previous record, end it.
if self.tr_recorder is not None:
# Don't free the handle, someone else may be using it...
self.end_tr(tmp_time)
# May want to establish predecessor/successor relation
# (don't free handle until then)
if self.is_recording_enabled():
db = self.stream_handle.get_db()
self.end_time = -1
self.begin_time = tmp_time
if (parent_recorder is None):
self.tr_recorder = self.stream_handle.open_recorder(self.get_type_name(),
self.begin_time,
"Begin_No_Parent, Link")
else:
self.tr_recorder = self.stream_handle.open_recorder(self.get_type_name(),
self.begin_time,
"Begin_End, Link")
if (self.tr_recorder is not None):
pass
#link = uvm_parent_child_link::get_link(parent_recorder, self.tr_recorder)
# TODO
#db.establish_link(link)
if (self.tr_recorder is not None):
m_begin_tr = self.tr_recorder.get_handle()
else:
m_begin_tr = 0
else:
self.tr_recorder = None
self.end_time = -1
self.begin_time = tmp_time
m_begin_tr = 0
self.do_begin_tr() # execute callback before event trigger
self.begin_event.trigger()
return m_begin_tr
#endfunction
#
#endclass
#------------------------------------------------------------------------------
# IMPLEMENTATION
#------------------------------------------------------------------------------
# get_initiator
# ------------
#
#function uvm_component uvm_transaction::get_initiator()
# return initiator
#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 is not None):
# tmp_initiator = initiator
# $swrite(str,"@%0d", tmp_initiator.get_inst_id())
# printer.print_generic("initiator", initiator.get_type_name(), -1, str)
# end
#endfunction
#
#function void uvm_transaction::do_copy (uvm_object rhs)
# uvm_transaction txn
# super.do_copy(rhs)
# if(rhs is None) return
# if(!$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
# self.tr_recorder = txn.self.tr_recorder
#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 is not None):
# uvm_recursion_policy_enum p = recorder.policy
# recorder.policy = UVM_REFERENCE
# recorder.record_object("initiator", initiator)
# recorder.policy = p
# end
#endfunction
#