Bitvis VIP Ethernet

Quick Access

HVVC

HVVC

This Ethernet Hierarchical-VVC is based on IEEE 802.3.
It does not support optional fields or EtherType, only length is supported.
HVVCs are different than normal VVCs since they represent a higher protocol level than the physical layer, i.e. they have no physical connections. However due to similarities in the core code, the VVC term is used instead.
HVVC functionality is implemented in ethernet_vvc.vhd
For general information see VVC Framework - Essential Mechanisms.

Entity

Generics

Name	Type	Default	Description
GC_INSTANCE_IDX	natural	N/A	Instance number to assign the VVC
GC_PHY_INTERFACE	t_interface	N/A	Physical VVC interface type, e.g. SBI, GMII. (see note below)
GC_PHY_VVC_INSTANCE_IDX	natural	N/A	Instance number of the physical VVC
GC_PHY_MAX_ACCESS_TIME	time	1 us	Maximum time that the physical VVC takes to execute an access, e.g. GMII write 1 byte. It should also account for any margin it needs.
GC_DUT_IF_FIELD_CONFIG	t_dut_if_field_config_direction_array	C_DUT_IF_FIELD_CONFIG_DIRECTION_ARRAY_DEFAULT	Array of configurations for address based VVC interfaces
GC_ETHERNET_PROTOCOL_CONFIG	t_ethernet_protocol_config	C_ETHERNET_PROTOCOL_CONFIG_DEFAULT	Configuration of the Ethernet protocol
GC_CMD_QUEUE_COUNT_MAX	natural	C_CMD_QUEUE_COUNT_MAX	Absolute maximum number of commands in the VVC command queue
GC_CMD_QUEUE_COUNT_THRESHOLD	natural	C_CMD_QUEUE_COUNT_THRESHOLD	An alert will be generated when reaching this threshold to indicate that the command queue is almost full. The queue will still accept new commands until it reaches GC_CMD_QUEUE_COUNT_MAX.
GC_CMD_QUEUE_COUNT_THRESHOLD_SEVERITY	t_alert_level	C_CMD_QUEUE_COUNT_THRESHOLD_SEVERITY	Alert severity which will be used when command queue reaches GC_CMD_QUEUE_COUNT_THRESHOLD
GC_RESULT_QUEUE_COUNT_MAX	natural	C_RESULT_QUEUE_COUNT_MAX	Maximum number of unfetched results before result_queue is full
GC_RESULT_QUEUE_COUNT_THRESHOLD	natural	C_RESULT_QUEUE_COUNT_THRESHOLD	An alert will be issued if result queue exceeds this count. Used for early warning if result queue is almost full. Will be ignored if set to 0.
GC_RESULT_QUEUE_COUNT_THRESHOLD_SEVERITY	t_alert_level	C_RESULT_QUEUE _COUNT_THRESHOLD_SEVERITY	Severity of alert to be initiated if exceeding GC_RESULT_QUEUE_COUNT_THRESHOLD

Note

You can use any of the physical interfaces already implemented just by using the appropriate name in GC_PHY_INTERFACE and instantiating the corresponding VVC in the testbench (in addition to the HVVC). For more information see VVC Framework - Essential Mechanisms. If you however want to use an interface type which is not already included, see Bitvis VIP HVVC-to-VVC Bridge for more info.

Signals

Since HVVCs represent a higher protocol level than the physical layer, they have no physical connections. The actual signals controlled by the HVVC are those from the physical interface defined by GC_PHY_INTERFACE and GC_PHY_VVC_INSTANCE_IDX.

Configuration Record

vvc_config accessible via shared_ethernet_vvc_config

Record element	Type	Default	Description
inter_bfm_delay	t_inter_bfm_delay	C_ETHERNET_INTER_BFM_DELAY_DEFAULT	Delay between any requested BFM accesses towards the DUT. TIME_START2START: Time from a BFM start to the next BFM start (a TB_WARNING will be issued if access takes longer than TIME_START2START). TIME_FINISH2START: Time from a BFM end to the next BFM start. Any insert_delay() command will add to the above minimum delays, giving for instance the ability to skew the BFM starting time.
cmd_queue_count_max	natural	C_CMD_QUEUE_COUNT_MAX	Maximum pending number in command queue before queue is full. Adding additional commands will result in an ERROR.
cmd_queue_count_threshold	natural	C_CMD_QUEUE_COUNT_THRESHOLD	An alert will be issued if command queue exceeds this count. Used for early warning if command queue is almost full. Will be ignored if set to 0.
cmd_queue_count_threshold_severity	t_alert_level	C_CMD_QUEUE_COUNT_THRESHOLD_SEERITY	Severity of alert to be initiated if exceeding cmd_queue_count_threshold
result_queue_count_max	natural	C_RESULT_QUEUE_COUNT_MAX	Maximum number of unfetched results before result_queue is full
result_queue_count_threshold	natural	C_RESULT_QUEUE_COUNT_THRESHOLD	An alert will be issued if result queue exceeds this count. Used for early warning if result queue is almost full. Will be ignored if set to 0.
result_queue_count_threshold_severity	t_alert_level	C_RESULT_QUEUE_COUNT_THRESHOLD_SEVERITY	Severity of alert to be initiated if exceeding result_queue_count_threshold
bfm_config	t_ethernet_protocol_config	C_ETHERNET_PROTOCOL_CONFIG_DEFAULT	Not strictly a bus functional model (BFM) but holds BFM-like configuration data for the Ethernet protocol
msg_id_panel	t_msg_id_panel	C_ETHERNET_VVC_MSG_ID_PANEL_DEFAULT	VVC dedicated message ID panel. See Scope of Verbosity Control for how to use verbosity control.

Note

cmd/result queue parameters in the configuration record are unused and will be removed in v3.0, use instead the entity generic constants.

The configuration record can be accessed from the Central Testbench Sequencer through the shared variable array, e.g.

shared_ethernet_vvc_config(RX, C_VVC_IDX).inter_bfm_delay.delay_in_time := 50 ns;
shared_ethernet_vvc_config(TX, C_VVC_IDX).bfm_config.interpacket_gap_time := 96 ns;

Status Record

vvc_status accessible via shared_ethernet_vvc_status

The current status of the VVC can be retrieved during simulation. This is achieved by reading from the shared variable from the test sequencer. The record contents can be seen below:

Record element	Type	Description
current_cmd_idx	natural	Command index currently running
previous_cmd_idx	natural	Previous command index to run
pending_cmd_idx	natural	Pending number of commands in the command queue

Methods

All VVC procedures are defined in vvc_methods_pkg.vhd (dedicated to this VVC).
See Common VVC Methods for procedures which are common to all VVCs.
It is also possible to send a multicast to all instances of a VVC with ALL_INSTANCES as parameter for vvc_instance_idx.
All parameters in brackets are optional.

ethernet_transmit()

Adds a transmit command to the Ethernet VVC executor queue, which will runs as soon as all preceding commands have completed. When the command is scheduled to run, the executor calls the priv_ethernet_transmit_to_bridge() procedure. This procedure builds an Ethernet packet and transmits each field using the HVVC-to-VVC bridge which then transfers the data to the lower level VVC (physical interface). After it has finished, it waits for the configured interpacket gap time.

ethernet_transmit(VVCT, vvc_instance_idx, channel, [mac_destination], [mac_source], payload, msg, [scope])

Object	Name	Dir.	Type	Description
signal	VVCT	inout	t_vvc_target_record	VVC target type compiled into each VVC in order to differentiate between VVCs
constant	vvc_instance_idx	in	integer	Instance number of the VVC
constant	channel	in	t_channel	The VVC channel of the VVC instance
constant	mac_destination	in	unsigned(47 downto 0)	The MAC address of destination
constant	mac_source	in	unsigned(47 downto 0)	The MAC address of source
constant	payload	in	t_byte_array	The payload of the packet
constant	msg	in	string	A custom message to be appended in the log/alert
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
ethernet_transmit(ETHERNET_VVCT, 0, TX, v_mac_dest, v_mac_src, v_payload, "Transmit an ethernet packet", C_SCOPE);
ethernet_transmit(ETHERNET_VVCT, 0, TX, v_payload, "Transmit an ethernet packet using default MAC addresses");

ethernet_receive()

Adds a receive command to the Ethernet VVC executor queue, which will run as soon as all preceding commands have completed. When the command is scheduled to run, the executor calls the priv_ethernet_receive_from_bridge() procedure. This procedure receives an Ethernet packet by requesting each field from the HVVC-to-VVC bridge which calls the lower level VVC (physical interface) to read the data. When the complete packet is received, it computes the FCS and checks that it corresponds to the one received in the packet.

The received data from the DUT is not to be returned in this procedure call since it is non-blocking for the sequencer/caller, but it will be stored in the VVC for a potential future fetch (see example with fetch_result below). If the data_routing is set to TO_SB, the read data will be sent to the Ethernet VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench).

ethernet_receive(VVCT, vvc_instance_idx, channel, [data_routing], msg, [scope])

Object	Name	Dir.	Type	Description
signal	VVCT	inout	t_vvc_target_record	VVC target type compiled into each VVC in order to differentiate between VVCs
constant	vvc_instance_idx	in	integer	Instance number of the VVC
constant	channel	in	t_channel	The VVC channel of the VVC instance
constant	data_routing	in	t_data_routing	Selects the destination of the read data
constant	msg	in	string	A custom message to be appended in the log/alert
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
ethernet_receive(ETHERNET_VVCT, 0, RX, "Receive an ethernet packet and store it in the VVC", C_SCOPE);
ethernet_receive(ETHERNET_VVCT, 0, RX, TO_SB, "Receive an ethernet packet and send to Scoreboard for checking");

-- Example with fetch_result() call: Result is placed in v_result
variable v_cmd_idx : natural;                       -- Command index for the last receive
variable v_result  : work.vvc_cmd_pkg.t_vvc_result; -- Result from receive.
...
ethernet_receive(ETHERNET_VVCT, 0, RX, "Receive ethernet packet");
v_cmd_idx := get_last_received_cmd_idx(ETHERNET_VVCT, 0, RX);
await_completion(ETHERNET_VVCT, 0, RX, v_cmd_idx, 1 us, "Wait for receive to finish");
fetch_result(ETHERNET_VVCT, 0, RX, v_cmd_idx, v_result, "Fetching result from receive operation");

Hint

t_vvc_result is defined in the corresponding vvc_cmd_pkg.vhd for the VIP.

ethernet_expect()

Adds an expect command to the Ethernet VVC executor queue, which will run as soon as all preceding commands have completed. When the command is scheduled to run, the executor calls the priv_ethernet_expect_from_bridge() procedure. This procedure performs a receive operation, then checks if the received data is equal to the expected data. The received data is not stored in this procedure.

ethernet_expect(VVCT, vvc_instance_idx, channel, [mac_destination], [mac_source], payload, msg, [alert_level, [scope]])

Object	Name	Dir.	Type	Description
signal	VVCT	inout	t_vvc_target_record	VVC target type compiled into each VVC in order to differentiate between VVCs
constant	vvc_instance_idx	in	integer	Instance number of the VVC
constant	channel	in	t_channel	The VVC channel of the VVC instance
constant	mac_destination	in	unsigned(47 downto 0)	The MAC address of destination
constant	mac_source	in	unsigned(47 downto 0)	The MAC address of source
constant	payload	in	t_byte_array	The payload of the packet
constant	msg	in	string	A custom message to be appended in the log/alert
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is ERROR.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
ethernet_expect(ETHERNET_VVCT, 0, RX, v_mac_dest, v_mac_src, v_payload, "Expect an ethernet packet", ERROR, C_SCOPE);

Activity Watchdog

The VVCs support a centralized VVC activity register which the activity watchdog uses to monitor the VVC activities. The VVCs will register their presence to the VVC activity register at start-up, and report when ACTIVE and INACTIVE, using dedicated VVC activity register methods, and trigger the global_trigger_vvc_activity_register signal during simulations. The activity watchdog is continuously monitoring the VVC activity register for VVC inactivity and raises an alert if no VVC activity is registered within the specified timeout period.

Include activity_watchdog(num_exp_vvc, timeout, [alert_level, [msg]]) in the testbench to start using the activity watchdog. Note that setting the exact number of expected VVCs in the VVC activity register can be omitted by setting num_exp_vvc = 0.

More information can be found in Essential Mechanisms - Activity Watchdog.

Transaction Info

This VVC supports transaction info, a UVVM concept for distributing transaction information in a controlled manner within the complete testbench environment. The transaction info may be used in many different ways, but the main purpose is to share information directly from the VVC to a DUT model.

Ethernet transaction info record fields. Transaction Type: t_base_transaction (BT) - accessible via **shared_ethernet_vvc_transaction_info.bt**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
ethernet_frame	t_ethernet_frame	C_ETHERNET_FRAME_DEFAULT	Ethernet frame
vvc_meta	t_vvc_meta	C_VVC_META_DEFAULT	VVC meta data of the executing VVC command
-> msg	string	“”	Message of executing VVC command
-> cmd_idx	integer	-1	Command index of executing VVC command
transaction_status	t_transaction_status	INACTIVE	Set to INACTIVE, IN_PROGRESS, FAILED or SUCCEEDED during a transaction

More information can be found in Essential Mechanisms - Distribution of Transaction Info.

Scoreboard

This VVC has built in Scoreboard functionality where data can be routed by setting the TO_SB parameter in supported method calls, i.e. ethernet_receive(). Note that the data is only stored in the scoreboard and not accessible with the fetch_result() method when the TO_SB parameter is applied. The Ethernet scoreboard is accessible from the testbench as a shared variable ETHERNET_VVC_SB, located in the vvc_methods_pkg.vhd, e.g.

ETHERNET_VVC_SB.add_expected(C_ETH_GMII_VVC_IDX, v_expected_frame, "Adding expected");

See the Bitvis VIP Scoreboard for a complete list of available commands and additional information. All of the listed Generic Scoreboard commands are available for the Ethernet VVC scoreboard using the ETHERNET_VVC_SB.

Unwanted Activity Detection

Since HVVCs do not contain any physical ports, the unwanted activity detection is found in the physical layer VVC connected to the HVVC, e.g. GMII/RGMII/SBI. Thus, when the data is not expected from the DUT, i.e. Ethernet VVC receive/expect methods are not called, an alert of severity will be generated from the physical layer VVCs.

The unwanted activity detection can be configured from the central testbench sequencer, where the severity of alert can be changed to a different value. To disable this feature in the testbench, e.g. for GMII VVC:

shared_gmii_vvc_config(RX, C_VVC_INDEX).unwanted_activity_severity := NO_ALERT;

Note that the unwanted activity detection is enabled (unwanted_activity_severity := ERROR) by default for the GMII/RGMII/SBI VVCs.

More information can be found in Essential Mechanisms - Unwanted Activity Detection.

Support package

Contains constants and types for the Ethernet protocol, defined in support_pkg.vhd

The table below shows which index in the DUT IF field configuration array (t_dut_if_field_config_direction_array) the Ethernet fields are associated with. These configurations are only necessary when the lower level VVC is address-based, e.g. SBI. The DUT IF field configuration array is a two-dimensional array (direction and index). If the same configuration is used for all fields, only one configuration per direction is needed. The highest indexed configuration is used for indexes higher than those supplied. E.g. if the array consists of two configurations the first configuration, index 0, is used for the field preamble & SFD and the other fields use the last configuration, index 1. Each index holds an element of type t_dut_if_field_config, see table below.

Ethernet field	Name	Index
Preamble & SFD	C_FIELD_IDX_PREAMBLE_AND_SFD	0
MAC destination	C_FIELD_IDX_MAC_DESTINATION	1
MAC source	C_FIELD_IDX_MAC_SOURCE	2
Payload length	C_FIELD_IDX_PAYLOAD_LENGTH	3
Payload	C_FIELD_IDX_PAYLOAD	4
FCS	C_FIELD_IDX_FCS	5

t_ethernet_protocol_config

Record element	Type
mac_destination	unsigned(47 downto 0)
mac_source	unsigned(47 downto 0)
fcs_error_severity	t_alert_level
interpacket_gap_time	time

Note

Interpacket gap is implemented as a wait statement after the ethernet packet has been transmitted.
Check of interpacket gap on receive is not implemented.
If the physical VVC has a timeout, e.g. max_wait_cycles, it must be big enough to handle the interpacket gap and any other delays in the transmission.

t_ethernet_frame

Record element	Type
mac_destination	unsigned(47 downto 0)
mac_source	unsigned(47 downto 0)
payload_length	integer
payload	t_byte_array(0 to 1499)
fcs	std_logic_vector(31 downto 0)

Compilation

The Ethernet VVC must be compiled with VHDL-2008 or newer. It is dependent on the following libraries:

UVVM Utility Library (UVVM-Util)

UVVM VVC Framework

Bitvis VIP Scoreboard

Library of the physical interface used (e.g. Bitvis VIP GMII)

HVVC-to-VVC Bridge

Before compiling the Ethernet VVC, assure that uvvm_util, uvvm_vvc_framework and bitvis_vip_scoreboard have been compiled.

See Essential Mechanisms - Compile Scripts for information about compile scripts.

Compile order for the Ethernet VVC
Compile to library	File	Comment
bitvis_vip_ethernet	support_pkg.vhd	Ethernet support package
bitvis_vip_ethernet	transaction_pkg.vhd	Ethernet transaction package with DTT types, constants, etc.
bitvis_vip_ethernet	vvc_cmd_pkg.vhd	Ethernet VVC command types and operations
bitvis_vip_ethernet	../uvvm_vvc_framework/src_target_dependent/td_target_support_pkg.vhd	UVVM VVC target support package, compiled into this VVC library
bitvis_vip_ethernet	../uvvm_vvc_framework/src_target_dependent/td_vvc_framework_common_methods_pkg.vhd	Common UVVM framework methods compiled into the this VVC library
bitvis_vip_ethernet	vvc_sb_pkg.vhd	Ethernet VVC scoreboard
bitvis_vip_ethernet	vvc_methods_pkg.vhd	Ethernet VVC methods
bitvis_vip_ethernet	../uvvm_vvc_framework/src_target_dependent/td_queue_pkg.vhd	UVVM queue package for this VVC
bitvis_vip_ethernet	../uvvm_vvc_framework/src_target_dependent/td_vvc_entity_support_pkg.vhd	UVVM VVC entity support compiled into this VVC library
bitvis_vip_ethernet	ethernet_rx_vvc.vhd	Ethernet RX VVC
bitvis_vip_ethernet	ethernet_tx_vvc.vhd	Ethernet TX VVC
bitvis_vip_ethernet	ethernet_vvc.vhd	Ethernet VVC wrapper for the RX and TX VVCs
bitvis_vip_ethernet	vvc_context.vhd	Ethernet VVC context file

Simulator compatibility and setup

See Prerequisites for a list of supported simulators.
For required simulator setup see UVVM-Util Simulator compatibility and setup.

Additional Documentation

Important

This is a simplified Verification IP (VIP) for Ethernet.
This Ethernet VVC is based on IEEE 802.3
It does not support optional fields or EtherType, only length is supported.
This VIP is not an Ethernet protocol checker.
For a more advanced VIP please contact UVVM support at info@uvvm.org

Note

Disclaimer: This IP and any part thereof are provided “as is”, without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non-infringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with this IP.