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BFM
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BFM

BFM functionality is implemented in axi_bfm_pkg.vhd

Signal Record

t_axi_if

Record element	Type
write_address_channel	t_axi_write_address_channel
write_data_channel	t_axi_write_data_channel
write_response_channel	t_axi_write_response_channel
read_address_channel	t_axi_read_address_channel
read_data_channel	t_axi_read_data_channel

Note

For more information on the AXI4 signals, refer to “AMBA® AXI™ and ACE™ Protocol Specification”, Part A (ARM IHI 0022G) available from ARM.

Configuration Record

t_axi_bfm_config

Default value for the record is C_AXI_BFM_CONFIG_DEFAULT.

Record element	Type	Default	Description
general_severity	t_alert_level	ERROR	Severity level for various checks of expected behavior in AXI4 transactions
max_wait_cycles	natural	1000	The maximum number of clock cycles to wait for the DUT ready or valid signals before reporting a timeout alert
max_wait_cycles_severity	t_alert_level	TB_FAILURE	The above timeout will have this severity
clock_period	time	-1 ns	Period of the clock signal
clock_period_margin	time	0 ns	Input clock period margin to specified clock_period. Will check ‘T/2’ if input clock is low when BFM is called and ‘T’ if input clock is high.
clock_margin_severity	t_alert_level	TB_ERROR	The above margin will have this severity
setup_time	time	-1 ns	Generated signals setup time. Suggested value is clock_period/4. An alert is reported if setup_time exceeds clock_period/2.
hold_time	time	-1 ns	Generated signals hold time. Suggested value is clock_period/4. An alert is reported if hold_time exceeds clock_period/2.
bfm_sync	t_bfm_sync	SYNC_ON_CLOCK_ONLY	When set to SYNC_ON_CLOCK_ONLY the BFM will enter on the first falling edge, estimate the clock period, synchronize the output signals and exit ¼ clock period after a succeeding rising edge. When set to SYNC_WITH_SETUP_AND_HOLD the BFM will use the configured setup_time, hold_time and clock_period to synchronize output signals with clock edges.
match_strictness	t_match_strictness	MATCH_EXACT	Matching strictness for std_logic values in check procedures. MATCH_EXACT requires both values to be the same. Note that the expected value can contain the don’t care operator ‘-‘. MATCH_STD allows comparisons between ‘H’ and ‘1’, ‘L’ and ‘0’ and ‘-’ in both values.
num_aw_pipe_stages	natural	1	Write Address Channel pipeline steps
num_w_pipe_stages	natural	1	Write Data Channel pipeline steps
num_ar_pipe_stages	natural	1	Read Address Channel pipeline steps
num_r_pipe_stages	natural	1	Read Data Channel pipeline steps
num_b_pipe_stages	natural	1	Response Channel pipeline steps
id_for_bfm	t_msg_id	ID_BFM	Message ID used for logging general messages in the BFM
id_for_bfm_wait	t_msg_id	ID_BFM_WAIT	Message ID used for logging waits in the BFM
id_for_bfm_poll	t_msg_id	ID_BFM_POLL	Message ID used for logging polling in the BFM

Methods

All signals are active high.
All parameters in brackets are optional.

axi_write()

Writes the given data to the given address of the DUT, using the AXI4 protocol. For protocol details, see the AXI4 specification.

The procedure reports an alert if:

wready does not occur within max_wait_cycles clock cycles (alert level: max_wait_cycles_severity, set in the config)

awready does not occur within max_wait_cycles clock cycles (alert level: max_wait_cycles_severity, set in the config)

bvalid is not set within max_wait_cycles clock cycles (alert level: max_wait_cycles_severity, set in the config)

axi_write(awid_value, awaddr_value, awlen_value, awsize_value, awburst_value, awlock_value, awcache_value, awprot_value,
          awqos_value, awregion_value, awuser_value, wdata_value, wstrb_value, wuser_value, buser_value, bresp_value, msg, clk,
          axi_if, [scope, [msg_id_panel, [config]]])

Object	Name	Dir.	Type	Description
constant	awid_value	in	std_logic_vector	Identification tag for a write transaction. Default value is 0x0.
constant	awaddr_value	in	unsigned	The address of the first transfer in a write transaction
constant	awlen_value	in	unsigned(7 downto 0)	The number of data transfers in a write transaction transaction. Default value is 0x0.
constant	awsize_value	in	integer	The number of bytes in each data transfer in a write transaction (must be a power of 2). Default value is 4.
constant	awburst_value	in	t_axburst	Burst type, indicates how address changes between each transfer in a write transaction. Default value is INCR.
constant	awlock_value	in	t_axlock	Provides information about the atomic characteristics of a write transaction. Default value is NORMAL.
constant	awcache_value	in	std_logic_vector(3 downto 0)	Indicates how a write transaction is required to progress through a system. Default value is 0x0.
constant	awprot_value	in	t_axprot	Protection attributes of a write transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	awqos_value	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a write transaction. Default value is 0x0.
constant	awregion_value	in	std_logic_vector(3 downto 0)	Region indicator for a write transaction. Default value is 0x0.
constant	awuser_value	in	std_logic_vector	User-defined extension for the write address channel. Default value is 0x0.
constant	wdata_value	in	t_slv_array	Array of data values to be written to the addressed registers
constant	wstrb_value	in	t_slv_array	Array of write strobes, indicates which byte lanes hold valid data (all ‘1’ means all bytes are updated). Default value is C_EMPTY_SLV_ARRAY.
constant	wuser_value	in	t_slv_array	Array of user-defined extension for the write data channel. Default value is C_EMPTY_SLV_ARRAY.
variable	buser_value	out	std_logic_vector	Output variable containing the user-defined extension for the write response channel
variable	bresp_value	out	t_xresp	Output variable containing the write response which indicates the status of a write transaction
constant	msg	in	string	A custom message to be appended in the log/alert
signal	clk	in	std_logic	The clock signal used to read and write data in/out of the AXI4 BFM
signal	axi_if	inout	t_axi_if	AXI4 signal interface record
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“AXI_BFM”).
constant	msg_id_panel	in	t_msg_id_panel	Controls verbosity within a specified scope. Default value is shared_msg_id_panel.
constant	config	in	t_axi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_AXI_BFM_CONFIG_DEFAULT.

-- Examples:
axi_write(
  awid_value     => x"01",
  awaddr_value   => x"00000004",
  awlen_value    => x"01",
  awsize_value   => 4,
  awburst_value  => INCR,
  awlock_value   => NORMAL,
  awcache_value  => "0000",
  awprot_value   => UNPRIVILEGED_NONSECURE_DATA,
  awqos_value    => "0000",
  awregion_value => "0000",
  awuser_value   => x"01",
  wdata_value    => t_slv_array'(x"12345678", x"33333333"),
  wstrb_value    => t_slv_array'(x"F", x"F"),
  wuser_value    => t_slv_array'(x"01", x"01"),
  buser_value    => v_buser_value,
  bresp_value    => v_bresp_value,
  msg            => "Writing data to Peripheral 1",
  clk            => clk,
  axi_if         => axi_if,
  scope          => C_SCOPE,
  msg_id_panel   => shared_msg_id_panel,
  config         => C_AXI_BFM_CONFIG_DEFAULT);

axi_write(
  awaddr_value   => x"00000004",
  wdata_value    => t_slv_array'(x"12345678", x"33333333"),
  buser_value    => v_buser_value,
  bresp_value    => v_bresp_value,
  msg            => "Writing data to Peripheral 1");

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
axi_write(C_ADDR_DMA, x"AAAA", "Writing data to DMA");
axi_write(C_ADDR_MEMORY, x"FF", v_data_array, "Writing 256 data words to MEMORY");

axi_read()

Reads data from the DUT at the given address, using the AXI4 protocol. For protocol details, see the AXI4 specification. The read data is placed on the output ‘rdata_value’ when the read has completed.

The procedure reports an alert if:

The received rid is different from the transmitted arid_value

arready does not occur within max_wait_cycles clock cycles (alert level: max_wait_cycles_severity, set in the config)

rvalid is not set within max_wait_cycles clock cycles (alert level: max_wait_cycles_severity, set in the config)

axi_read(arid_value, araddr_value, arlen_value, arsize_value, arburst_value, arlock_value, arcache_value, arprot_value, arqos_value,
         arregion_value, aruser_value, rdata_value, rresp_value, ruser_value, msg, clk, axi_if, [scope, [msg_id_panel, [config]]])

Object	Name	Dir.	Type	Description
constant	arid_value	in	std_logic_vector	Identification tag for a read transaction. Default value is 0x0.
constant	araddr_value	in	unsigned	The address of the first transfer in a read transaction
constant	arlen_value	in	unsigned(7 downto 0)	The number of data transfers in a read transaction transaction. Default value is 0x0.
constant	arsize_value	in	integer	The number of bytes in each data transfer in a read transaction (must be a power of 2). Default value is 4.
constant	arburst_value	in	t_axburst	Burst type, indicates how address changes between each transfer in a read transaction. Default value is INCR.
constant	arlock_value	in	t_axlock	Provides information about the atomic characteristics of a read transaction. Default value is NORMAL.
constant	arcache_value	in	std_logic_vector(3 downto 0)	Indicates how a read transaction is required to progress through a system. Default value is 0x0.
constant	arprot_value	in	t_axprot	Protection attributes of a read transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	arqos_value	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a read transaction. Default value is 0x0.
constant	arregion_value	in	std_logic_vector(3 downto 0)	Region indicator for a read transaction. Default value is 0x0.
constant	aruser_value	in	std_logic_vector	User-defined extension for the read address channel. Default value is 0x0.
variable	rdata_value	out	t_slv_array	Output variable containing an array of read data
variable	rresp_value	out	t_xresp_array	Output variable containing an array of read responses which indicates the status of a read transfer
variable	ruser_value	out	t_slv_array	Output variable containing an array of user-defined extensions for the read data channel
constant	msg	in	string	A custom message to be appended in the log/alert
signal	clk	in	std_logic	The clock signal used to read and write data in/out of the AXI4 BFM
signal	axi_if	inout	t_axi_if	AXI4 signal interface record
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“AXI_BFM”).
constant	msg_id_panel	in	t_msg_id_panel	Controls verbosity within a specified scope. Default value is shared_msg_id_panel.
constant	config	in	t_axi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_AXI_BFM_CONFIG_DEFAULT.

-- Examples:
axi_read(
  arid_value     => x"01",
  araddr_value   => x"00000004",
  arlen_value    => x"01",
  arsize_value   => 4,
  arburst_value  => INCR,
  arlock_value   => NORMAL,
  arcache_value  => "0000",
  arprot_value   => UNPRIVILEGED_NONSECURE_DATA,
  arqos_value    => "0000",
  arregion_value => "0000",
  aruser_value   => x"01",
  rdata_value    => v_rdata_value,
  rresp_value    => v_rresp_value,
  ruser_value    => v_ruser_value,
  msg            => "Read from Peripheral 1",
  clk            => clk,
  axi_if         => axi_if,
  scope          => C_SCOPE,
  msg_id_panel   => shared_msg_id_panel,
  config         => C_AXI_BFM_CONFIG_DEFAULT);

axi_read(
  araddr_value   => x"00000004",
  rdata_value    => v_rdata_value,
  rresp_value    => v_rresp_value,
  ruser_value    => v_ruser_value,
  msg            => "Read from Peripheral 1",
  clk            => clk,
  axi_if         => axi_if);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
axi_read(C_ADDR_IO, v_data_out, "Reading from IO device");
axi_read(C_ADDR_MEMORY, x"FF", v_data_array_out, "Reading 256 data words from MEMORY");

axi_check()

Reads data from the DUT at the given address, using the AXI4 protocol. For protocol details, see the AXI4 specification. After reading data from the AXI4 bus, the read data is compared with the expected data, and if they don’t match, an alert with severity ‘alert_level’ is reported. The procedure also report alerts for the same conditions as the axi_read() procedure.

axi_check(arid_value, araddr_value, arlen_value, arsize_value, arburst_value, arlock_value, arcache_value, arprot_value, arqos_value,
          arregion_value, aruser_value, rdata_exp, rresp_exp, ruser_exp, msg, clk, axi_if, [alert_level, [scope, [msg_id_panel, [config]]]])

Object	Name	Dir.	Type	Description
constant	arid_value	in	std_logic_vector	Identification tag for a read transaction. Default value is 0x0.
constant	araddr_value	in	unsigned	The address of the first transfer in a read transaction
constant	arlen_value	in	unsigned(7 downto 0)	The number of data transfers in a read transaction transaction. Default value is 0x0.
constant	arsize_value	in	integer	The number of bytes in each data transfer in a read transaction (must be a power of 2). Default value is 4.
constant	arburst_value	in	t_axburst	Burst type, indicates how address changes between each transfer in a read transaction. Default value is INCR.
constant	arlock_value	in	t_axlock	Provides information about the atomic characteristics of a read transaction. Default value is NORMAL.
constant	arcache_value	in	std_logic_vector(3 downto 0)	Indicates how a read transaction is required to progress through a system. Default value is 0x0.
constant	arprot_value	in	t_axprot	Protection attributes of a read transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	arqos_value	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a read transaction. Default value is 0x0.
constant	arregion_value	in	std_logic_vector(3 downto 0)	Region indicator for a read transaction. Default value is 0x0.
constant	aruser_value	in	std_logic_vector	User-defined extension for the read address channel. Default value is 0x0.
constant	rdata_exp	in	t_slv_array	Array of expected read data values. A mismatch results in an alert ‘alert_level’
constant	rresp_exp	in	t_xresp_array	Array of expected read responses which indicates the status of a read transfer. Default value is OKAY for all words.
constant	ruser_exp	in	t_slv_array	Array of expected user-defined extensions for the read data channel. Default value is 0x0 for all words.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	clk	in	std_logic	The clock signal used to read and write data in/out of the AXI4 BFM
signal	axi_if	inout	t_axi_if	AXI4 signal interface record
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is C_AXI_BFM_CONFIG_DEFAULT.general_severity.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“AXI_BFM”).
constant	msg_id_panel	in	t_msg_id_panel	Controls verbosity within a specified scope. Default value is shared_msg_id_panel.
constant	config	in	t_axi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_AXI_BFM_CONFIG_DEFAULT.

-- Examples:
axi_check(
  arid_value     => x"01",
  araddr_value   => x"00000004",
  arlen_value    => x"01",
  arsize_value   => 4,
  arburst_value  => INCR,
  arlock_value   => NORMAL,
  arcache_value  => "0000",
  arprot_value   => UNPRIVILEGED_NONSECURE_DATA,
  arqos_value    => "0000",
  arregion_value => "0000",
  aruser_value   => x"01",
  rdata_exp      => t_slv_array'(x"12345678", x"33333333"),
  rresp_exp      => t_xresp_array'(OKAY, OKAY),
  ruser_exp      => t_slv_array'(x"00", x"00"),
  msg            => "Check data from Peripheral 1",
  clk            => clk,
  axi_if         => axi_if,
  alert_level    => ERROR,
  scope          => C_SCOPE,
  msg_id_panel   => shared_msg_id_panel,
  config         => C_AXI_BFM_CONFIG_DEFAULT);

axi_check(
  araddr_value   => x"00000004",
  rdata_exp      => v_rdata_exp,
  msg            => "Check data from Peripheral 1",
  clk            => clk,
  axi_if         => axi_if);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
axi_check(C_ADDR_UART_RX, x"3B", "Checking data in UART RX register");
axi_check(C_ADDR_MEMORY, x"FF", v_rdata_exp_array, "Checking 256 data words from MEMORY");

init_axi_if_signals()

Initializes the AXI4 interface. All the BFM outputs are set to ‘0’, and BFM inputs are set to ‘Z’. This function assumes that awid, bid, arid and rid shares a common width (id_width) and that awuser, buser, aruser, ruser also share a common width (user_width).

t_axi_if := init_axi_if_signals(addr_width, data_width, id_width, user_width)

Object	Name	Dir.	Type	Description
constant	addr_width	in	natural	Width of the address signals
constant	data_width	in	natural	Width of the data signals
constant	id_width	in	natural	Width of the id signals
constant	user_width	in	natural	Width of the user signals

-- Examples:
axi_if <= init_axi_if_signals(addr_width, data_width, id_width, user_width)

Local types

t_axi_write_address_channel

Record element	Type
awid	std_logic_vector
awaddr	std_logic_vector
awlen	std_logic_vector(7 downto 0)
awsize	std_logic_vector(2 downto 0)
awburst	std_logic_vector(1 downto 0)
awlock	std_logic
awcache	std_logic_vector(3 downto 0)
awprot	std_logic_vector(2 downto 0)
awqos	std_logic_vector(3 downto 0)
awregion	std_logic_vector(3 downto 0)
awuser	std_logic_vector
awvalid	std_logic
awready	std_logic

t_axi_write_data_channel

Record element	Type
wdata	std_logic_vector
wstrb	std_logic_vector
wlast	std_logic
wuser	std_logic_vector
wvalid	std_logic
wready	std_logic

t_axi_write_response_channel

Record element	Type
bid	std_logic_vector
bresp	std_logic_vector(1 downto 0)
buser	std_logic_vector
bvalid	std_logic
bready	std_logic

t_axi_read_address_channel

Record element	Type
arid	std_logic_vector
araddr	std_logic_vector
arlen	std_logic_vector(7 downto 0)
arsize	std_logic_vector(2 downto 0)
arburst	std_logic_vector(1 downto 0)
arlock	std_logic
arcache	std_logic_vector(3 downto 0)
arprot	std_logic_vector(2 downto 0)
arqos	std_logic_vector(3 downto 0)
arregion	std_logic_vector(3 downto 0)
aruser	std_logic_vector
arvalid	std_logic
arready	std_logic

t_axi_read_data_channel

Record element	Type
rid	std_logic_vector
rdata	std_logic_vector
rresp	std_logic_vector(1 downto 0)
rlast	std_logic
ruser	std_logic_vector
rvalid	std_logic
rready	std_logic

t_axburst

FIXED, INCR, WRAP

t_axlock

NORMAL, EXCLUSIVE

t_axprot

UNPRIVILEGED_NONSECURE_DATA, UNPRIVILEGED_NONSECURE_INSTRUCTION, UNPRIVILEGED_SECURE_DATA, UNPRIVILEGED_SECURE_INSTRUCTION, PRIVILEGED_NONSECURE_DATA, PRIVILEGED_NONSECURE_INSTRUCTION, PRIVILEGED_SECURE_DATA, PRIVILEGED_SECURE_INSTRUCTION

t_xresp

OKAY, EXOKAY, SLVERR, DECERR, ILLEGAL

t_xresp_array

array (natural range <>) of t_xresp;

Local BFM overloads

A good approach for better readability and maintainability is to make simple, local overloads for the BFM procedures in the TB process. This allows calling the BFM procedures with the key parameters only, e.g.

axi_write(C_ADDR_PERIPHERAL_1, C_TEST_DATA, "Sending data to Peripheral 1");

rather than

axi_write(
  awid_value     => x"01",
  awaddr_value   => x"00000004",
  awlen_value    => x"01",
  awsize_value   => 4,
  awburst_value  => INCR,
  awlock_value   => NORMAL,
  awcache_value  => "0000",
  awprot_value   => UNPRIVILEGED_NONSECURE_DATA,
  awqos_value    => "0000",
  awregion_value => "0000",
  awuser_value   => x"01",
  wdata_value    => t_slv_array'(x"12345678", x"33333333"),
  wstrb_value    => t_slv_array'(x"F", x"F"),
  wuser_value    => t_slv_array'(x"01", x"01"),
  buser_value    => v_buser_value,
  bresp_value    => v_bresp_value,
  msg            => "Writing data to Peripheral 1",
  clk            => clk,
  axi_if         => axi_if,
  scope          => C_SCOPE,
  msg_id_panel   => shared_msg_id_panel,
  config         => C_AXI_BFM_CONFIG_DEFAULT);

By defining the local overload as e.g.

procedure axi_write(
  constant addr_value   : in unsigned;
  constant data_value   : in std_logic_vector;
  constant msg          : in string
) is
  variable v_buser_value : std_logic_vector(C_USER_WIDTH - 1 downto 0);
  variable v_bresp_value : t_xresp;
begin
  axi_write(
    awid_value     => x"00",                       -- Setting a default value
    awaddr_value   => addr_value,                  -- Keep as is
    awlen_value    => x"00",                       -- Set to length=1
    awsize_value   => 4,                           -- Setting a default value
    awburst_value  => INCR,                        -- Setting a default value
    awlock_value   => NORMAL,                      -- Setting a default value
    awcache_value  => "0000",                      -- Setting a default value
    awprot_value   => UNPRIVILEGED_NONSECURE_DATA, -- Setting a default value
    awqos_value    => "0000",                      -- Setting a default value
    awregion_value => "0000",                      -- Setting a default value
    awuser_value   => x"01",                       -- Setting a default value
    wdata_value    => data_value,                  -- Keep as is
    wstrb_value    => x"f"                         -- Setting a default value
    wuser_value    => x"01",                       -- Setting a default value
    buser_value    => v_buser_value,               -- Assigning to a local variable
    bresp_value    => v_bresp_value,               -- Assigning to a local variable
    msg            => msg,                         -- Keep as is
    clk            => clk,                         -- Signal must be visible in local process scope
    axi_if         => axi_if,                      -- Signal must be visible in local process scope
    scope          => C_SCOPE,                     -- Setting a default value
    msg_id_panel   => shared_msg_id_panel,         -- Use global, shared msg_id_panel
    config         => C_AXI_BFM_CONFIG_LOCAL);     -- Use locally defined configuration or C_AXI_BFM_CONFIG_DEFAULT
end procedure;

Using a local overload like this also allows the following – if wanted:

Have address value as natural – and convert in the overload
Set up defaults for constants. May be different for two overloads of the same BFM
Apply dedicated message ID panel to allow dedicated verbosity control

Compilation

This BFM package may only be compiled with VHDL-2008 or newer. It is dependent on the Utility Library, which is only compatible with VHDL-2008 or newer.
After UVVM-Util has been compiled, the BFM package can be compiled into any desired library.
See Essential Mechanisms - Compile Scripts for information about compile scripts.

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

For more information on the AXI4 specification, refer to “AMBA® AXI™ and ACE™ Protocol Specification”, Part A (ARM IHI 0022G), available from ARM.

Important

This is a simplified Bus Functional Model (BFM) for AXI4.
The given BFM complies with the basic AXI4 protocol and thus allows a normal access towards an AXI4 interface.
This BFM is not an AXI4 protocol checker.
For a more advanced BFM please contact UVVM support at info@uvvm.org

VVC

VVC functionality is implemented in axi_vvc.vhd
For general information see VVC Framework - Essential Mechanisms.

Entity

Generics

Name	Type	Default	Description
GC_ADDR_WIDTH	integer	8	Width of the AXI4 address bus (AWADDR, ARADDR)
GC_DATA_WIDTH	integer	32	Width of the AXI4 data bus (WDATA, RDATA). The write strobe (WSTRB) is derived from this (GC_DATA_WIDTH/8)
GC_ID_WIDTH	integer	8	Width of the AXI4 ID signals (AWID, BID, ARID, RID)
GC_USER_WIDTH	integer	8	Width of the AXI4 User signals (AWUSER, WUSER, BUSER, ARUSER, RUSER)
GC_INSTANCE_IDX	natural	1	Instance number to assign the VVC
GC_AXI_CONFIG	t_axi_bfm_config	C_AXI_BFM_CONFIG_DEFAULT	Configuration for the AXI4 BFM
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

Signals

Object	Name	Dir.	Type	Description
signal	clk	in	std_logic	VVC Clock signal
signal	axi_vvc_master_if	inout	t_axi_if	AXI4 signal interface record

In this VVC, the interface has been encapsulated in a signal record of type t_axi_if in order to improve readability of the code. Since the AXI4 interface buses can be of arbitrary size, the interface vectors have been left unconstrained. These unconstrained vectors need to be constrained when the interface signals are instantiated. For this interface, it could look like:

signal axi_if : t_axi_if(write_address_channel(awid  (C_ID_WIDTH      -1 downto 0),
                                               awaddr(C_ADDR_WIDTH    -1 downto 0),
                                               awuser(C_USER_WIDTH    -1 downto 0)),
                         write_data_channel   (wdata (C_DATA_WIDTH    -1 downto 0),
                                               wstrb ((C_DATA_WIDTH/8)-1 downto 0),
                                               wuser (C_USER_WIDTH    -1 downto 0)),
                         write_response_channel(bid  (C_ID_WIDTH      -1 downto 0),
                                                buser(C_USER_WIDTH    -1 downto 0)),
                         read_address_channel (arid  (C_ID_WIDTH      -1 downto 0),
                                               araddr(C_ADDR_WIDTH    -1 downto 0),
                                               aruser(C_USER_WIDTH    -1 downto 0)),
                         read_data_channel    (rid   (C_ID_WIDTH      -1 downto 0),
                                               rdata (C_DATA_WIDTH    -1 downto 0),
                                               ruser (C_USER_WIDTH    -1 downto 0)));

Configuration Record

vvc_config accessible via shared_axi_vvc_config

Record element	Type	Default	Description
inter_bfm_delay	t_inter_bfm_delay	C_AXI_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_axi_bfm_config	C_AXI_BFM_CONFIG_DEFAULT	Configuration for the AXI4 BFM
msg_id_panel	t_msg_id_panel	C_VVC_MSG_ID_PANEL_DEFAULT	VVC dedicated message ID panel. See Scope of Verbosity Control for how to use verbosity control.
force_single_pending_transac/ tion	boolean	false	Waits until the previous transaction is completed before starting the next one
unwanted_activity_severity	t_alert_level	C_UNWANTED_ACTIVITY_SEVERITY	Severity of alert to be issued if unwanted activity on the DUT outputs is detected. It is enabled with ERROR severity by default.

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_axi_vvc_config(1).inter_bfm_delay.delay_in_time := 50 ns;
shared_axi_vvc_config(1).bfm_config.clock_period := 10 ns;

Status Record

vvc_status accessible via shared_axi_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.

axi_write()

Adds a write command to the AXI4 VVC executor queue, which will distribute this command to the various channel executors which in turn will run as soon as all preceding commands have completed. When the command is scheduled to run, the executors call the AXI4 procedures in axi_channel_handler_pkg.vhd. This procedure can be called with or without parameters that already have a default value.

axi_write(VVCT, vvc_instance_idx, awid, awaddr, awlen, awsize, awburst, awlock, awcache, awprot, awqos, awregion, awuser, wdata,
          wstrb, wuser, bresp_exp, buser_exp, 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	awid	in	std_logic_vector	Identification tag for a write transaction. Default value is 0x0.
constant	awaddr	in	unsigned	The address of the first transfer in a write transaction
constant	awlen	in	unsigned(7 downto 0)	The number of data transfers in a write transaction transaction. Default value is 0x0.
constant	awsize	in	integer	The number of bytes in each data transfer in a write transaction (must be a power of 2). Default value is 4.
constant	awburst	in	t_axburst	Burst type, indicates how address changes between each transfer in a write transaction. Default value is INCR.
constant	awlock	in	t_axlock	Provides information about the atomic characteristics of a write transaction. Default value is NORMAL.
constant	awcache	in	std_logic_vector(3 downto 0)	Indicates how a write transaction is required to progress through a system. Default value is 0x0.
constant	awprot	in	t_axprot	Protection attributes of a write transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	awqos	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a write transaction. Default value is 0x0.
constant	awregion	in	std_logic_vector(3 downto 0)	Region indicator for a write transaction. Default value is 0x0.
constant	awuser	in	std_logic_vector	User-defined extension for the write address channel. Default value is 0x0.
constant	wdata	in	t_slv_array	Array of data values to be written to the addressed registers
constant	wstrb	in	t_slv_array	Array of write strobes, indicates which byte lanes hold valid data (all ‘1’ means all bytes are updated). Default value is C_EMPTY_SLV_ARRAY.
constant	wuser	in	t_slv_array	Array of user-defined extension for the write data channel. Default value is C_EMPTY_SLV_ARRAY.
constant	bresp_exp	in	t_xresp	Expected write response which indicates the status of a write transaction. Default value is OKAY.
constant	buser_exp	in	std_logic_vector	Expected user-defined extension for the write response channel. Default value is 0x0.
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:
axi_write(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  awid             => x"01",
  awaddr           => x"00000004",
  awlen            => x"01",
  awsize           => 4,
  awburst          => INCR,
  awlock           => NORMAL,
  awcache          => "0000",
  awprot           => UNPRIVILEGED_NONSECURE_DATA,
  awqos            => "0000",
  awregion         => "0000",
  awuser           => x"01",
  wdata            => t_slv_array'(x"12345678", x"33333333"),
  wstrb            => t_slv_array'(x"F", x"F"),
  wuser            => t_slv_array'(x"01", x"01"),
  bresp_exp        => OKAY,
  buser_exp        => x"00",
  msg              => "Writing data to Peripheral 1");

axi_write(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  awaddr           => x"00000004",
  wdata            => t_slv_array'(x"12345678", x"33333333"),
  msg              => "Writing data to Peripheral 1");

axi_read()

Adds a read command to the AXI4 VVC executor queue, which will distribute this command to the various channel executors which in turn will run as soon as all preceding commands have completed. When the command is scheduled to run, the executors call the AXI4 procedures in axi_channel_handler_pkg.vhd.

The value read from the DUT will not be returned in this procedure call since it is non-blocking for the sequencer/caller. If the data_routing parameter is set to TO_BUFFER, the read data will be stored in the VVC for a potential future fetch (see example with fetch_result below). If the data_routing parameter is set to TO_SB, the received data will be sent to the AXI4 VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench).

axi_read(VVCT, vvc_instance_idx, arid, araddr, arlen, arsize, arburst, arlock, arcache, arprot, arqos, arregion, aruser, 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	arid	in	std_logic_vector	Identification tag for a read transaction. Default value is 0x0.
constant	araddr	in	unsigned	The address of the first transfer in a read transaction
constant	arlen	in	unsigned(7 downto 0)	The number of data transfers in a read transaction transaction. Default value is 0x0.
constant	arsize	in	integer	The number of bytes in each data transfer in a read transaction (must be a power of 2). Default value is 4.
constant	arburst	in	t_axburst	Burst type, indicates how address changes between each transfer in a read transaction. Default value is INCR.
constant	arlock	in	t_axlock	Provides information about the atomic characteristics of a read transaction. Default value is NORMAL.
constant	arcache	in	std_logic_vector(3 downto 0)	Indicates how a read transaction is required to progress through a system. Default value is 0x0.
constant	arprot	in	t_axprot	Protection attributes of a read transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	arqos	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a read transaction. Default value is 0x0.
constant	arregion	in	std_logic_vector(3 downto 0)	Region indicator for a read transaction. Default value is 0x0.
constant	aruser	in	std_logic_vector	User-defined extension for the read address channel. Default value is 0x0.
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:
axi_read(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  arid             => x"01",
  araddr           => x"00000004",
  arlen            => x"01",
  arsize           => 4,
  arburst          => INCR,
  arlock           => NORMAL,
  arcache          => "0000",
  arprot           => UNPRIVILEGED_UNSECURE_DATA,
  arqos            => "0000",
  arregion         => "0000",
  aruser           => x"01",
  data_routing     => TO_SB,
  msg              => "Read from Peripheral 1 and send result to scoreboard");

axi_read(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  araddr           => x"00000004",
  data_routing     => TO_BUFFER,
  msg              => "Read from Peripheral 1 and send result to read buffer");

-- Example with fetch_result() call: Result is placed in v_result
variable v_cmd_idx : natural;                       -- Command index for the last read
variable v_result  : work.vvc_cmd_pkg.t_vvc_result; -- Result from read.
...
axi_read(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  araddr           => x"00000004",
  data_routing     => TO_BUFFER,
  msg              => "Read from Peripheral 1 and send result to read buffer");
v_cmd_idx := get_last_received_cmd_idx(AXI_VVCT, 0);
await_completion(AXI_VVCT, 0, v_cmd_idx, 100 ns, "Wait for read to finish");
fetch_result(AXI_VVCT, 0, v_cmd_idx, v_result, "Fetching result from read operation");

Hint

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

axi_check()

Adds a check command to the AXI4 VVC executor queue, which will distribute this command to the various channel executors which in turn will run as soon as all preceding commands have completed. When the command is scheduled to run, the executors call the AXI4 procedures in axi_channel_handler_pkg.vhd. The axi_check() procedure will perform a read operation, then check if the read result is equal to the rdata_exp, rresp_exp and ruser_exp parameters. If the result is not equal to the expected result, an alert with severity ‘alert_level’ will be issued. The read data will not be stored by this procedure.

axi_check(VVCT, vvc_instance_idx, arid, araddr, arlen, arsize, arburst, arlock, arcache, arprot, arqos, arregion, aruser, rdata_exp,
          rresp_exp, ruser_exp, 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	arid	in	std_logic_vector	Identification tag for a read transaction. Default value is 0x0.
constant	araddr	in	unsigned	The address of the first transfer in a read transaction
constant	arlen	in	unsigned(7 downto 0)	The number of data transfers in a read transaction transaction. Default value is 0x0.
constant	arsize	in	integer	The number of bytes in each data transfer in a read transaction (must be a power of 2). Default value is 4.
constant	arburst	in	t_axburst	Burst type, indicates how address changes between each transfer in a read transaction. Default value is INCR.
constant	arlock	in	t_axlock	Provides information about the atomic characteristics of a read transaction. Default value is NORMAL.
constant	arcache	in	std_logic_vector(3 downto 0)	Indicates how a read transaction is required to progress through a system. Default value is 0x0.
constant	arprot	in	t_axprot	Protection attributes of a read transaction. Privilege, security level and access type. Default value is UNPRIVILEGED_NONSECURE_DATA.
constant	arqos	in	std_logic_vector(3 downto 0)	Quality of Service identifier for a read transaction. Default value is 0x0.
constant	arregion	in	std_logic_vector(3 downto 0)	Region indicator for a read transaction. Default value is 0x0.
constant	aruser	in	std_logic_vector	User-defined extension for the read address channel. Default value is 0x0.
constant	rdata_exp	in	t_slv_array	Array of expected read data values. A mismatch results in an alert ‘alert_level’
constant	rresp_exp	in	t_xresp_array	Array of expected read responses which indicates the status of a read transfer. Default value is OKAY for all words.
constant	ruser_exp	in	t_slv_array	Array of expected user-defined extensions for the read data channel. Default value is 0x0 for all words.
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:
axi_check(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  arid             => x"01",
  araddr           => x"00000004",
  arlen            => x"01",
  arsize           => 4,
  arburst          => INCR,
  arlock           => NORMAL,
  arcache          => "0000",
  arprot           => UNPRIVILEGED_UNSECURE_DATA,
  arqos            => "0000",
  arregion         => "0000",
  aruser           => x"01",
  rdata_exp        => t_slv_array'(x"12345678", x"33333333"),
  rresp_exp        => t_xresp_array'(OKAY, OKAY),
  ruser_exp        => t_slv_array'(x"00", x"00"),
  msg              => "Check data from Peripheral 1");

axi_check(
  VVCT             => AXI_VVCT,
  vvc_instance_idx => 0,
  araddr           => x"00000004",
  rdata_exp        => t_slv_array'(x"12345678", x"33333333"),
  msg              => "Check data from Peripheral 1");

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.

AXI4 transaction info record fields. Transaction Type: t_base_transaction (BT) - accessible via **shared_axi_vvc_transaction_info.bt_wr** and **shared_axi_vvc_transaction_info.bt_rd**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
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

AXI4 transaction info record fields. Transaction type: t_arw_transaction (ST) - accessible via **shared_axi_vvc_transaction_info.st_aw** and **shared_axi_vvc_transaction_info.st_ar**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
arwid	std_logic_vector(31 downto 0)	0x0	Identification tag for a read or write transaction
arwaddr	unsigned(31 downto 0)	0x0	The address for a read or write transaction
arwlen	unsigned(7 downto 0)	0x0	Burst length for a read or write transaction
arwsize	integer	4	Burst size for a read or write transaction
arwburst	t_axburst	INCR	Burst type for a read or write transaction
arwlock	t_axlock	NORMAL	Lock value for a read or write transaction
arwcache	std_logic_vector(3 downto 0)	0x0	Cache value for a read or write transaction
arwprot	t_axprot	UNPRIVILEGED_NONSECURE_DATA	Protection value for a read or write transaction
arwqos	std_logic_vector(3 downto 0)	0x0	QoS value for a read or write transaction
arwregion	std_logic_vector(3 downto 0)	0x0	Region value for a read or write transaction
arwuser	std_logic_vector(127 downto 0)	0x0	User value for a read or write transaction
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

AXI4 transaction info record fields. Transaction type: t_w_transaction (ST) - accessible via **shared_axi_vvc_transaction_info.st_w**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
wdata	t_slv_array(0 to 255)(255 downto 0)	0x0	Write data
wstrb	t_slv_array(0 to 255)(31 downto 0)	0x0	Write strobe
wuser	t_slv_array(0 to 255)(127 downto 0)	0x0	User value
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

AXI4 transaction info record fields. Transaction type: t_b_transaction (ST) - accessible via **shared_axi_vvc_transaction_info.st_b**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
bid	std_logic_vector(31 downto 0)	0x0	Identification tag
bresp	t_xresp	OKAY	Write response
buser	std_logic_vector(127 downto 0)	0x0	User value for write response channel
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

AXI4 transaction info record fields. Transaction type: t_r_transaction (ST) - accessible via **shared_axi_vvc_transaction_info.st_r**
Info field	Type	Default	Description
operation	t_operation	NO_OPERATION	Current VVC operation, e.g. INSERT_DELAY, POLL_UNTIL, READ, WRITE
rid	std_logic_vector(31 downto 0)	0x0	Identification tag for read data channel
rdata	t_slv_array(0 to 255)(255 downto 0)	0x0	Read data array
rresp	t_xresp_array(0 to 255)	OKAY	Read response array
ruser	t_slv_array(0 to 255)(127 downto 0)	0x0	Read user extension array
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. axi_read(). 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 AXI4 scoreboard is accessible from the testbench as a shared variable AXI_VVC_SB, located in the vvc_methods_pkg.vhd, e.g.

AXI_VVC_SB.add_expected(C_AXI_VVC_IDX, v_expected, "Adding expected");

The AXI4 scoreboard is per default the maximum width of rid, rdata, rresp and ruser. When sending expected result to the scoreboard, where the result width is smaller than the default scoreboard width, we recommend zero-padding the data.

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 AXI4 VVC scoreboard using the AXI_VVC_SB.

Unwanted Activity Detection

This VVC supports detection of unwanted activity from the DUT. This mechanism will give an alert if the DUT generates any unexpected bus activity. It assures that no data is output from the DUT when it is not expected, i.e. read/receive/check/expect VVC methods are not called. Once the VVC is inactive, it starts to monitor continuously on the DUT outputs. When unwanted activity is detected, the VVC issues an alert.

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.

shared_axi_vvc_config(C_VVC_INDEX).unwanted_activity_severity := NO_ALERT;

Note that the ready signals (awready, wready, arready) are not monitored in this VVC. The ready signals are allowed to be set independently of the valid signals (awvalid, wvalid, arvalid), and there is no method to differentiate between the unwanted activity and intended activity. See the AXI4 protocol specification for more information.

The unwanted activity detection is ignored when the valid signals (bvalid, rvalid) go low within one clock period after the VVC becomes inactive. This is to handle the situation when the read command exits before the next rising edge, causing signal transitions during the first clock cycle after the VVC is inactive.

For AXI4 VVC, the unwanted activity detection is enabled by default with severity ERROR.

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

Compilation

The AXI4 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

AXI4 BFM

Before compiling the AXI4 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 AXI4 VVC
Compile to library	File	Comment
bitvis_vip_axi	axi_bfm_pkg.vhd	AXI4 BFM
bitvis_vip_axi	transaction_pkg.vhd	AXI4 transaction package with DTT types, constants, etc.
bitvis_vip_axi	vvc_cmd_pkg.vhd	AXI4 VVC command types and operations
bitvis_vip_axi	axi_read_data_queue_pkg.vhd	Package for storing read data responses in a queue to support out-of-order read data
bitvis_vip_axi	axi_channel_handler_pkg.vhd	Package containing procedures for accessing AXI4 channels. Only for use by the VVC.
bitvis_vip_axi	../uvvm_vvc_framework/src_target_dependent/td_target_support_pkg.vhd	UVVM VVC target support package, compiled into this VVC library
bitvis_vip_axi	../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_axi	vvc_sb_pkg.vhd	AXI4 VVC scoreboard
bitvis_vip_axi	vvc_methods_pkg.vhd	AXI4 VVC methods
bitvis_vip_axi	../uvvm_vvc_framework/src_target_dependent/td_queue_pkg.vhd	UVVM queue package for this VVC
bitvis_vip_axi	../uvvm_vvc_framework/src_target_dependent/td_vvc_entity_support_pkg.vhd	UVVM VVC entity support compiled into this VVC library
bitvis_vip_axi	axi_vvc.vhd	AXI4 VVC
bitvis_vip_axi	vvc_context.vhd	AXI4 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

For more information on the AXI4 specification, refer to “AMBA® AXI™ and ACE™ Protocol Specification”, Part A (ARM IHI 0022G), available from ARM.

Important

This is a simplified Verification IP (VIP) for AXI4.
The given VIP complies with the basic AXI4 protocol and thus allows a normal access towards an AXI4 interface.
This VIP is not an AXI4 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.