[source]

Class uvm_pkg::uvm_sqr_if_base

uvm_pkg::uvm_sqr_if_base <T1, T2> + disable_auto_item_recording(): void + get() + get_next_item() + has_do_available(): bit + is_auto_item_recording_enabled(): bit + item_done(): void + peek() + put() + put_response(): void + try_next_item() + wait_for_sequences()

Inheritance Diagram of uvm_sqr_if_base

CLASS

uvm_sqr_if_base #(REQ,RSP)

This class defines an interface for sequence drivers to communicate with sequencers. The driver requires the interface via a port, and the sequencer implements it and provides it via an export.

Parameters

Name

Default value

Description
T1

uvm_object
T2

T1

Functions

item_done(uvm_object t = null)

Function

item_done

Indicates that the request is completed to the sequencer. Any uvm_sequence_base::wait_for_item_done calls made by a sequence for this item will return.

The current item is removed from the sequencer FIFO.

If a response item is provided, then it will be sent back to the requesting sequence. The response item must have its sequence ID and transaction ID set correctly, using the uvm_sequence_item::set_id_info method:

  rsp.set_id_info(req);

Before item_done is called, any calls to peek will retrieve the current item that was obtained by get_next_item. After item_done is called, peek will cause the sequencer to arbitrate for a new item.

Parameters:

t (uvm_object)

has_do_available()

Function

has_do_available

Indicates whether a sequence item is available for immediate processing. Implementations should return 1 if an item is available, 0 otherwise.

put_response(uvm_object t)

Function

put_response

Sends a response back to the sequence that issued the request. Before the response is put, it must have its sequence ID and transaction ID set to match the request. This can be done using the uvm_sequence_item::set_id_info call:

rsp.set_id_info(req);

Parameters:

t (uvm_object)

disable_auto_item_recording()

Function

disable_auto_item_recording

By default, item recording is performed automatically when get_next_item() and item_done() are called. However, this works only for simple, in-order, blocking transaction execution. For pipelined and out-of-order transaction execution, the driver must turn off this automatic recording and call uvm_transaction::accept_tr, uvm_transaction::begin_tr and uvm_transaction::end_tr explicitly at appropriate points in time.

This methods be called at the beginning of the driver's run_phase() method. Once disabled, automatic recording cannot be re-enabled.

For backward-compatibility, automatic item recording can be globally turned off at compile time by defining UVM_DISABLE_AUTO_ITEM_RECORDING

is_auto_item_recording_enabled()

Function

is_auto_item_recording_enabled

Return TRUE if automatic item recording is enabled for this port instance.

Tasks

get_next_item(uvm_object t)

Task

get_next_item

Retrieves the next available item from a sequence. The call will block until an item is available. The following steps occur on this call:

1

Arbitrate among requesting, unlocked, relevant sequences - choose the highest priority sequence based on the current sequencer arbitration mode. If no sequence is available, wait for a requesting unlocked relevant sequence, then re-arbitrate.

2

The chosen sequence will return from wait_for_grant

3

The chosen sequence uvm_sequence_base::pre_do is called

4

The chosen sequence item is randomized

5

The chosen sequence uvm_sequence_base::post_do is called

6

Return with a reference to the item

Once get_next_item is called, item_done must be called to indicate the completion of the request to the sequencer. This will remove the request item from the sequencer FIFO.

Parameters:

t (uvm_object)

try_next_item(uvm_object t)

Task

try_next_item

Retrieves the next available item from a sequence if one is available. Otherwise, the function returns immediately with request set to null . The following steps occur on this call:

1

Arbitrate among requesting, unlocked, relevant sequences - choose the highest priority sequence based on the current sequencer arbitration mode. If no sequence is available, return null .

2

The chosen sequence will return from wait_for_grant

3

The chosen sequence uvm_sequence_base::pre_do is called

4

The chosen sequence item is randomized

5

The chosen sequence uvm_sequence_base::post_do is called

6

Return with a reference to the item

Once try_next_item is called, item_done must be called to indicate the completion of the request to the sequencer. This will remove the request item from the sequencer FIFO.

Parameters:

t (uvm_object)

wait_for_sequences()

Task

wait_for_sequences

Waits for a sequence to have a new item available. The default implementation in the sequencer calls uvm_wait_for_nba_region. User-derived sequencers may override its wait_for_sequences implementation to perform some other application-specific implementation.

get(uvm_object t)

Task

get

Retrieves the next available item from a sequence. The call blocks until an item is available. The following steps occur on this call:

1

Arbitrate among requesting, unlocked, relevant sequences - choose the highest priority sequence based on the current sequencer arbitration mode. If no sequence is available, wait for a requesting unlocked relevant sequence, then re-arbitrate.

2

The chosen sequence will return from uvm_sequence_base::wait_for_grant

3

The chosen sequence uvm_sequence_base::pre_do is called

4

The chosen sequence item is randomized

5

The chosen sequence uvm_sequence_base::post_do is called

6

Indicate item_done to the sequencer

7

Return with a reference to the item

When get is called, item_done may not be called. A new item can be obtained by calling get again, or a response may be sent using either put, or uvm_driver::rsp_port.write().

Parameters:

t (uvm_object)

peek(uvm_object t)

Task

peek

Returns the current request item if one is in the sequencer FIFO. If no item is in the FIFO, then the call will block until the sequencer has a new request. The following steps will occur if the sequencer FIFO is empty:

1

Arbitrate among requesting, unlocked, relevant sequences - choose the highest priority sequence based on the current sequencer arbitration mode. If no sequence is available, wait for a requesting unlocked relevant sequence, then re-arbitrate.

2

The chosen sequence will return from uvm_sequence_base::wait_for_grant

3

The chosen sequence uvm_sequence_base::pre_do is called

4

The chosen sequence item is randomized

5

The chosen sequence uvm_sequence_base::post_do is called

Once a request item has been retrieved and is in the sequencer FIFO, subsequent calls to peek will return the same item. The item will stay in the FIFO until either get or item_done is called.

Parameters:

t (uvm_object)

put(uvm_object t)
Parameters:

t (uvm_object)