UVM 1. 2 Release Notes

uvm_event should be a parameterized class

The uvm_event class was split into two classes, an abstract uvm_event_base, and a parameterized uvm_event#(T).

This should have minimal backwards compatibility concerns, as any code using uvm_event without explicitly declaring a #(T) will default to uvm_event#(uvm_object).

Deprecate get_config/set_config interface for configuration

The methods set_config_int, set_config_string and set_config_object (and their get counterparts) are now deprecated in favor of uvm_config_int, uvm_config_string and uvm_config_object.

ref guide doesn’t show names of UVM runtime phases

The documentation for UVM Common Phases and UVM Run-Time Phases has been updated to include a definition of how phases are named.

UVM_DISABLE_AUTO_ITEM_RECORDING should be a run_time option

uvm_sqr_if_base#(REQ,RSP)::disable_auto_item_recording and uvm_sqr_if_base#(REQ,RSP)::is_auto_item_recording_enabled have been added to the uvm_sqr_if_base#(REQ,RSP) class, allowing the driver runtime control over whether or not a sequencer should automatically record the items which flow through the sequence item port.

Setting enum values by name from command line doesn’t work

The uvm_enum_wrapper#(T) utility class has been added, which provides the ability to retrieve an enum value when provided with a string matching the enum.name() for that value.

This class is used by the `uvm_field_enum macro when performing auto-configuration, such that values can be set using uvm_config_db#(string) (or the uvm_cmdline_processor::+uvm_set_config_string plusarg).

Phase’s default sequence should also have get_config string support

A new plusarg has been added (uvm_cmdline_processor::+uvm_set_default_sequence) which allows for the default_sequence a sequencer executes in uvm_sequencer_base::start_phase_sequence to be set directly from the command line.

General support for setting default_sequence as a string was not provided, as during runtime the default_sequence should always be set using either uvm_sequence_base or uvm_object_wrapper.

Remove all $display calls from BCL, except report_server

All messaging is now routed via uvm_report_server.

request facility to identify unused factory overrides

The uvm_factory class was split into two classes, an abstract uvm_factory, a default implementation of uvm_default_factory.  This allows for alternate factories (including those with additional debug functionality) to be created.

Control over the global factory was migrated to the new uvm_coreservice_t class.

Feature request to create a non-hierarchical objection

uvm_objection::set_propagate_mode has been added to provide control over whether or not objections propagate.

Feature request to prevent objection from throwing decrement-below-zero error if the count is 0

An error is no longer produced if uvm_objection::drop_objection is called with a count of 0, when the current object count is 0.

Not possible to undo a factory override.

A factory override can now be “undone” by supplying a type as an override for itself.

i.e.

// Perform an override
set_type_override_by_type(old_type::get_type(), new_type::get_type());
// Undo the override
set_type_override_by_type(old_type::get_type(), old_type::get_type());

bug in the get_full_name method of uvm_reg_file.

The get_full_name method of uvm_reg_file now includes the top-level block name.

uvm_comparer not using verbosity setting for print_msg()

The uvm_comparer::print_msg method now obeys the uvm_comparer::verbosity setting.

transaction order unclear and cant be changed when bus/reg size differ

The ordering of transactions generated when the size of a register/field is different than the size of the bus can now be controlled via the new uvm_reg_transaction_order_policy class.

Volatile fields should always need updating

Volatile register fields will always cause a write(), even if mirrored and desired values are the same.

Add UVM_ prefix to enumerated values

Various top-level enumeration values (such as those declared in uvm_sequence_state_enum) did not have the UVM_ prefix.  This would cause compilation errors when the uvm_pkg was wildcard imported into a scope which had already declared the same names.  These enumerations have been corrected to include the proper UVM_ prefix.

Bad reference to “record_field_int” in reference guide

A bad reference to record_field_int has been corrected to record_field inside of uvm_recorder.

Bad reference to “DEC” in reference guide

Bad references to “DEC” have been corrected to UVM_DEC within uvm_object::do_print and uvm_object::do_record.

uvm_sequence_library documentation missing from html documentation

The uvm_sequence_library class has been updated from “beta” to “official” status.  As such, it is now documented in the reference guide.

Documentation of uvm_component::set_inst_override_by_type() incorrectly documents uvm_factory::set_inst_override_by_type()

The documentation of uvm_component::set_inst_override_by_type as been updated to reflect the proper ordering of the parameters to uvm_factory::set_inst_override_by_type.

some symbols in uvm_radix_enum undocumented

Documentation was added for UVM_UNFORMAT2, UVM_UNFORMAT4, UVM_REAL, UVM_REAL_DEC, and UVM_REAL_EXP within the uvm_radix_enum.

Deprecate hierarchical propagation of objections; add mode bit in interim

Mantis 3893 (+) provides the mode bit for controlling propagation of objections.  Hierarchical propagation was not outright deprecated in this release.

Redundant code in uvm_port_base

Some redundant code in the uvm_port_base#(IF) was removed.

Remove the confusing uvm_severity type

The confusing uvm_severity_type was deprecated, and replaced internally using uvm_severity.

set_report_verbosity doc unclear about setting value or threshold

The documentation of uvm_report_object::set_report_verbosity_level, uvm_report_object::set_report_id_verbosity, and uvm_report_object::set_report_severity_id_verbosity were updated to provide a clearer definition of exactly what the verbosity values implied.

BUSY flag not cleared when register model is reset

The register model was updated to clear the BUSY flag when reset.

Refactor start_phase_sequence logic to be able to kill sequence on phase ending

The method uvm_sequencer_base::stop_phase_sequence was added which acts as the bookend to uvm_sequencer_base::start_phase_sequence.  It will call uvm_sequence_base::kill on the default_sequence if the sequence is still executing when the phase ends.

Enhance uvm_sequence::starting_phase

The uvm_sequence_base::starting_phase variable was publicly accessible and not protected from writes-after-reads.  This would result in strange behavior (including FATALS and HANGS) if the value was changed between a raise and drop of the objection within the phase.

The variable was removed, and is now only accessible via the uvm_sequence_base::set_starting_phase and uvm_sequence_base::get_starting_phase accessors.  An error will be thrown if there are any attempts to ‘set’ the starting phase after it has been retrieved via a ‘get’.

Provide auto-object-to-phase in uvm_sequence_base

The uvm_sequence_base::set_automatic_phase_objection method was added, simplifying the code required to object to the starting_phase inside of a phase.

Clean up the number of objections created by phasing

Objections only make sense in uvm_task_phases which are of the UVM_PHASE_IMP type.  For all other phases and types, the objections have been removed, and any attempt to access the objection will result in an error.

Provide get_objection_count in uvm_phase

The method uvm_phase::get_objection_count was added, providing the user with a cleaner mechanism for dropping all raised objections.

// Old Code:
uvm_objection phase_done;
phase_done = phase.get_objection();
phase_done.drop_objection(this,
                          "dropping all objections",
                          phase_done.get_objection_count(this));

// New Code:
phase.drop_objection(this,
                     "dropping all objections",
                     phase.get_objection_count(this));

seq_item_port.put_response is not documented

The previously undocumented uvm_sqr_if_base#(REQ,RSP)::put_response was added to the standard, providing a non-blocking mechanism for sending response information from a driver.

jump logic too early in phase state pipeline

The previous implementation of the jump logic uvm_phase caused jumps during the phase_ended callback to be ignored.  This has been corrected.

Provide schedule introspection via get_predecessor/successor_nodes

The uvm_phase::get_adjacent_predecessor_nodes and uvm_phase::get_adjacent_successor_nodes methods were adding the uvm_phase api.  This provides the user with the ability to programmatically traverse the entire phase graph.

uvm_sequence fields req/rsp are not documented

The previously undocumented uvm_sequence#(REQ,RSP)::req and uvm_sequence#(REQ,RSP)::rsp fields were added to the standard.

sequencer_base should throw error if user allows wait_for_relevant to return while is_relevant=0

An error will now be thrown if the sequencer exceeds the allowable number of returns from uvm_sequence_base::wait_for_relevant without uvm_sequence_base::is_relevant returning true.  The allowable maximum number can be controlled via the uvm_sequencer_base::set_max_zero_time_wait_relevant_count method.

Add uvm_mem_mam_policy allocator to uvm_vreg::allocate()

The uvm_vreg::allocate API was expanded to include an optional third alloc argument.

Remove the unnecessary over-prioritization of uvm_sequence_base in default_sequence

The previous implementation of uvm_sequencer_base over-prioritized default_sequence configurations which were of type uvm_sequence_base, such that they would override configurations of type uvm_object_wrapper, even if the wrapper configurations were done with higher precedence.

Add phase-transition callbacks

The uvm_phase_cb and uvm_phase_cb_pool were added to provide additional hooks into the phasing API.

Make UVM_OBJECT_MUST_HAVE_CONSTRUCTOR the default behavior

Mantis 3770 provided the ability to optionally enforce an explicit constructor with a string-type name argument in the UVM 1.1a, via the `UVM_OBJECT_MUST_HAVE_CONSTRUCTOR symbol.  This functionality is now the default behavior for the UVM.

Enable all flavors of phase jumping

The uvm_phase’s jump API was extended to include uvm_phase::set_jump_phase and uvm_phase::end_prematurely.  These methods allow for a “softer” jump wherein the phase’s execution is not immediately terminated.

uvm_reg_access_seq ignoring regs with one RO field

The uvm_reg_access_seq implementation was incorrectly skipping registers which contained any ‘RO’ fields, as opposed to registers which had only ‘RO’ fields.  This behavior has been corrected.

initialized memory on DPI side may survive reset and will cause bad behaviour

The C-side of the UVM’s internal DPI calls was not safe during a simulation reset, and could potentially cause memory leaks and bad behavior.  This has been corrected.

uvm_test_done should be made “const”

The undocumented and deprecated uvm_pkg::uvm_test_done reference was made const to prevent users from accidently changing it.

are uvm tlm connections with non-uvm_object a legal/supported use model?

The TLM documentation was expanded to explicitly allow non-uvm_object-based types within their parameterization.

Infinite recursion in uvm_reg_field::get_access

An error message within the uvm_reg_field::get_access method was recursively calling uvm_reg_field::get_access, resulting in an infinite recursion.  This behavior was corrected.

Additionally, while fixing this mantis is was determined that the map of field accesses defined in uvm_reg_field::set_access was lacking a name for the scenario caused when a ‘RO’ field was added to a ‘WO’ map.  The “NOACCESS” policy was added to handle this scenario.

cleanup static dpi issues

This mantis wrapped various fixes within the C-side of DPI used within the UVM.

comparer.show_max can cause check to pass when length mismatches

A bug in the uvm_comparer class caused queues of different sizes to false-pass when the uvm_comparer::show_max value was not equal to ‘1’.  This behavior has been corrected.

uvm_reg::do_predict ignoring UVM_NOT_OK

The uvm_reg::do_predict method was overwriting UVM_NOT_OK status under certain circumstances, and replacing it with UVM_IS_OK.  This behavior has been corrected.

Messaging System Revamp

The reporting system was overhauled to use an object-based approach to passing information (as opposed to passing many fields multiple times).  This simultaneously expanded the functionality of the messaging API while providing an easier path for adding functionality to this section of the standard in the future.

packing/unpacking issues

The uvm_packer::pack_int method (which has been renamed to uvm_packer::pack_field) was incorrectly implemented, causing big endian packs of 64+ bits to be preocessed incorrectly.  Additionally, the `uvm_unpack_array implementation did not work properly when uvm_packer::use_metadata was set to ‘0’.  These behaviors have been corrected.

Bugs in UVM 1.1-c: uvm_reg_tlm_adapter::reg2bus()

Various fixes we provided for uvm_reg_tlm_adapter::reg2bus such that iw would properly adhere to uvm_tlm_gp rules for length, byte_enable, and byte_enable_length.

in-built sequence is not equipped to exclude a block from the test sequence

The uvm_reg_hw_reset_seq was updated to ensure sub-blocks were properly excluded when relevant NO_REG_TEST attributes were set.

update uvm_hdl.c to allow VCS/IUS to perform backdoor access to VHDL

The capability to allow VHDL UVM_REG backdoor access using VCS and IUS were added.

uvm_report_server is not really extendable/chainable

In a fix similar to Mantis 3887 (*), uvm_report_server was also split into two classes, an abstract uvm_report_server and a default implementation of uvm_default_report_server.  This allows uvm_report_server to be fully extended, and multiple report servers can be chained together using a “delegate” pattern.

Control over the global report server was migrated to the new uvm_coreservice_t class.

uvm_report_cb::add_by_name example needs review

A bad example in the documentation of uvm_report_cb::add_by_name has been fixed.

resource lookup broken/undefined when fieldname has wildcards

Meta characters (globs or regular expressions) within the fieldname of a resource are no longer interpretted by the resource pool.

printing of int fields will mask Z values with X

The uvm_printer::print_field and uvm_printer::print_field_int methods were incorrectly implemented, causing ‘Z’ values to appear as ‘X’ when printed.  This behavior has been corrected.

uvm_phase::unsync() does not work

The implementation of uvm_phase::unsync was updated to properly remove the sync relationship.

uvm_dpi_get_next_arg_c doesnt fully adhere to -1800-lrm

The internal method uvm_dpi_get_next_arg_c was updated to completely adhere to the 1800 lrm.

Improve memory performance of ‘bitstream’ interfaces for report/record/etc.

The new uvm_integral_t was standardized, which is a less memory-expensive packed vector than the uvm_bitstream_t.  Support for this new type was added to the uvm_printer, uvm_packer, uvm_recorder and uvm_comparer, as well as the auto-configuration provided by the `uvm_field_*macros.

uvm_config_db::set expects to be invoked in process context

The implementation of uvm_config_db::set was improperly assuming that the method would be invoked within a process context (i.e. process.self() != null).  This behavior has been corrected.

remove uvm_global_copy_map

The internal and undocumented uvm_global_copy_map was removed and replaced by a simple associative array.

predict updated not just the mirrored field

The documentation of the uvm_reg::predict and uvm_reg_field::predict methods was clarified to indicate that the methods update both the mirrored and desired values.

Typo in uvm_sequence_base.vh (mehod should be method)

A typo in the documentation of uvm_sequence_base was corrected.

uvm macros violate 1800lrm iterator requirements

The `uvm_field_*macros were updated to obey 1800 LRM requirements for the iterators of arrays.

Static initialization races

The fix to Mantis 4606 accidently included a static race condition which was fixed.

uvm_phase_state initializes to incorrect value

The new phase state UVM_PHASE_UNINITIALIZED was added to the uvm_phase_state.  This new state is the default state for all phases after construction.

Bug in uvm_reg_map::get_size();

The implementation of uvm_reg_map::get_size had a typo which resulted in the value of the last offset added being used instead of the value of the largest offset.  This behavior has been corrected.

DPI Code does not use UVM Messaging

Similar to Mantis 3783, the messages generated from the C-side implementation of the UVM dpi code have been refactored to route through standard UVM messaging.

Promote get_next_item, try_next_item, item_done, get, peek, and put to be a part of the standard

The documentation of the uvm_sequencer#(REQ,RSP)::Sequencer Interface was expanded to include the implementations of the various methods.

Recording System Revamp

Similar to Mantis 4570 (*)(+), the recording system was overhauled to use an object-based approach to connecting to transaction databases.  This resulted in two new classes uvm_tr_stream and uvm_tr_database, which provided an object-based implementation of the undocumented implementation API for the uvm_recorder.

Additionally, a new data policy uvm_link_base was added for expressing arbitrary relationships in a compile-safe manner.

Fix broken `uvm_record_field + `uvm_record_attribute interaction

The fix for this mantis involved creating a new method uvm_recorder::use_record_attribute.  The new method allows for a conditional usage of the `uvm_record_attribute macro, allowing users to create their own recorders without interfering with vendor-specific recorders

`uvm_pack_int and `uvm_unpack_int bypass the uvm_packer policy methods

The previous implementation of the `uvm_pack_* macros bypassed the uvm_packer policy methods, and directly accessed an undocumented member variable of the uvm_packer class.  This implementation was refactored to use the policy methods without accessing any undocumented functionality.

Additionally, a new API was added to the uvm_packer to provide the ability to pack/unpack an arbrary number of bits from an array of bits, bytes or ints.  This new API provides easier compatibility with the SystemVerilog stream operator.

separate uvm_hdl* source into files-by-vendor

Related to Mantis 4588, the fix for this mantis separated the hdl vendor dpi implementations into vendor-specific files.

`uvm_record_* macros bypass uvm_recorder policy class

The previously undocumented `uvm_record_* macros bypassed the uvm_recorder policy methods, and called undocumented and non-standard methods.  Their implementation has been refactored to use the uvm_recorder policy methods by default.

print_real is undocumented

A typo in the documentation of uvm_printer::print_real resulted in the method being absent from the standard.  This has been corrected.

`uvm_record_int/string/time/real are undocumented

After fixing Mantis 4783 (*), the previously undocumented `uvm_record_int, `uvm_record_field, `uvm_record_real, `uvm_record_string and `uvm_record_time have been officially added to the standard.

Adding a uvm_reg_map to an existing regmap instance required both maps to have the same parent.  The behavior was fixed and the bad error message corrected.

Fixed a problem wherein multiple +uvm_set_* commands were ignored after a format error.

The instance name of the phase objection was changed to reflect the name of the phase.

A performance fix was implemented which avoided the copy of large QDA within the spell checker.

Fixed a bug within uvm_leaf_scope which could lead to stall of simulation.

Fixed random stability bug in lookup_name which caused instability when the config database was queried.

A check was added for an out-of-bound queue access in uvm_misc.svh.  This check caused no functional change, but prevents certain tools from throwing a warning when processing the code.

The macros `UVM_MAX_STREAMBITS, `UVM_PACKER_MAX_BYTES and `UVM_DEFAULT_TIMEOUT were relocated to src/macros/uvm_global_defines.svh, which is included via uvm_macros.svh.  These changes will make the UVM 1.2 Reference HTML out of sync with the UVM 1.2 Reference PDF, however this change is strictly contained to the formatting/location of documentation, not a functional difference.

Various typos and bad links within the reference guide were corrected.