Bitvis VIP SPI

Quick Access

• BFM

  • spi_master_transmit_and_receive()

  • spi_master_transmit_and_check()

  • spi_master_transmit()

  • spi_master_receive()

  • spi_master_check()

  • init_spi_if_signals()

  • spi_slave_transmit_and_receive()

  • spi_slave_transmit_and_check()

  • spi_slave_transmit()

  • spi_slave_receive()

  • spi_slave_check()

• VVC

  • spi_master_transmit_and_receive()

  • spi_master_transmit_and_check()

  • spi_master_transmit_only()

  • spi_master_receive_only()

  • spi_master_check_only()

  • spi_slave_transmit_and_receive()

  • spi_slave_transmit_and_check()

  • spi_slave_transmit_only()

  • spi_slave_receive_only()

  • spi_slave_check_only()

---

BFM

BFM functionality is implemented in spi_bfm_pkg.vhd

Signal Record

t_spi_if

Record element	Type
ss_n	std_logic
sclk	std_logic
mosi	std_logic
miso	std_logic

Note

Some BFM calls can also be made with listing of single signals rather than t_spi_if.

Configuration Record

t_spi_bfm_config

Default value for the record is C_SPI_BFM_CONFIG_DEFAULT.

Record element	Type	Default	Description
CPOL	std_logic	‘0’	sclk polarity, i.e. the base value of the clock. If CPOL is ‘0’, the clock will be set to ‘0’ when inactive, i.e., positive polarity.
CPHA	std_logic	‘0’	sclk phase, i.e. when data is sampled and transmitted w.r.t. sclk. If ‘0’, sampling occurs on the first sclk edge and data is transmitted on the sclk active to idle state. If ‘1’, data is sampled on the second sclk edge and transmitted on sclk idle to active state.
spi_bit_time	time	-1 ns	Used in master for dictating the sclk period. Will give a TB_ERROR if not set to a different value than -1.
ss_n_to_sclk	time	20 ns	Time from ss_n low until sclk active
sclk_to_ss_n	time	20 ns	Time from last sclk until ss_n is released
inter_word_delay	time	0 ns	Minimum time between words, from ss_n inactive to ss_n active
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.
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	DEPRECATED
id_for_bfm_poll	t_msg_id	ID_BFM_POLL	DEPRECATED

Methods

• The record t_spi_if can be replaced with the signals listed in said record in some methods.

• All signals are active high.

• All parameters in brackets are optional.

Note

The BFM configuration has to be defined and used when calling the SPI BFM procedures. See Local BFM configuration for an example of how to define a local BFM config.

spi_master_transmit_and_receive()

Transmits the data in ‘tx_data’ to the DUT and stores the received data in ‘rx_data’, using the SPI protocol. For protocol details, see the SPI specification.

When called, the procedure will set ss_n low. For a slave DUT to be able to transmit to a receiving master BFM, the master BFM must drive the sclk and ss_n signals and transmit data to the slave DUT.

• This procedure is responsible for driving sclk and ss_n.

• The SPI bit timing is given by config.spi_bit_time, config.spi_ss_n_to_sclk and config.sclk_to_ss_n.

• An error is reported if ss_n is not kept low during the entire transmission.

• Note that action_between_words only apply for t_slv_array multi-word transfers.

spi_master_transmit_and_receive(tx_data(slv), rx_data(slv), msg, spi_if, [action_when_transfer_is_done, [scope, [msg_id_panel, [config]]]])
spi_master_transmit_and_receive(tx_data(slv_array), rx_data(slv_array), msg, spi_if, [action_when_transfer_is_done, [action_between_words, [scope, [msg_id_panel, [config]]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
variable	rx_data	out	std_logic_vector t_slv_array	The data value received from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_master_transmit_and_receive(x"AA", v_data_out, "Transmitting data to peripheral 1 and receiving data back", spi_if);
spi_master_transmit_and_receive((x"AA", x"BB"), v_data_out, "Transmitting data to peripheral 1 and receiving data back", spi_if,
                                RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS, C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_master_transmit_and_receive(C_ASCII_A, v_data_out, "Transmitting ASCII A to DUT and receiving data from DUT");

spi_master_transmit_and_check()

Transmits the data in ‘tx_data’ and receives data from the DUT, using the transmit and receive procedure as described in spi_master_transmit_and_receive(). After receiving data, the data is compared with the expected data.

• If the check was successful, and the received data matches the expected data, a log message is written with ID ‘config.id_for_bfm’.

• If the received data did not match the expected data, an alert with severity ‘alert_level’ will be reported.

• The procedure will report alerts for the same conditions and use similar default values as the spi_master_transmit_and_receive() procedure.

• Note that action_between_words only apply for t_slv_array multi-word transfers.

spi_master_transmit_and_check(tx_data(slv), data_exp(slv), msg, spi_if, [alert_level, [action_when_transfer_is_done, [scope, [msg_id_panel, [config]]]]])
spi_master_transmit_and_check(tx_data(slv_array), data_exp(slv_array), msg, spi_if, [alert_level, [action_when_transfer_is_done, [action_between_words, [scope, [msg_id_panel, [config]]]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is ERROR.
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_master_transmit_and_check(x"AA", x"3B", "Transmitting data and checking received data on SPI interface", spi_if);
spi_master_transmit_and_check((x"AA", x"BB"), (x"3A", x"3B"), "Transmitting data and checking received data on SPI interface",
                              spi_if, ERROR, RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS, C_SCOPE, shared_msg_id_panel,
                              C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_master_transmit_and_check(x"AA", C_CR_BYTE, "Transmitting 0xAA and expecting carriage return");

spi_master_transmit()

Transmits the data in ‘tx_data’ using the transmit and receive procedure as described in spi_master_transmit_and_receive().

• The received data from the DUT is ignored.

• The procedure will report alerts for the same conditions and use similar default values as the spi_master_transmit_and_receive() procedure.

• Note that action_between_words only apply for t_slv_array multi-word transfers.

spi_master_transmit(tx_data(slv), msg, spi_if, [action_when_transfer_is_done, [scope, [msg_id_panel, [config]]]])
spi_master_transmit(tx_data(slv_array), msg, spi_if, [action_when_transfer_is_done, [action_between_words, [scope, [msg_id_panel, [config]]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_master_transmit(x"AA", "Transmitting data to peripheral 1", spi_if);
spi_master_transmit((x"AA", x"BB"), "Transmitting data to peripheral 1", spi_if, RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS,
                    C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_master_transmit(C_ASCII_A, "Transmitting ASCII A to DUT");

spi_master_receive()

Receives data from the DUT using the transmit and receive procedure as described in spi_master_transmit_and_receive().

• The procedure will transmit dummy data (0x0) to the DUT.

• The procedure will report alerts for the same conditions and use similar default values as the spi_master_transmit_and_receive() procedure.

• Note that action_between_words only apply for t_slv_array multi-word transfers.

spi_master_receive(rx_data(slv), msg, spi_if, [action_when_transfer_is_done, [scope, [msg_id_panel, [config]]]])
spi_master_receive(rx_data(slv_array), msg, spi_if, [action_when_transfer_is_done, [action_between_words, [scope, [msg_id_panel, [config]]]]])

Object	Name	Dir.	Type	Description
variable	rx_data	out	std_logic_vector t_slv_array	The data value received from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_master_receive(v_data_out, "Receive from Peripheral 1", spi_if);
spi_master_receive(v_data_out, "Receive from Peripheral 1", spi_if, RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS,
                   C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_master_receive(v_data_out, "Receive from Peripheral 1");

spi_master_check()

Receives data from the DUT, using the transmit and receive procedure as described in spi_master_transmit_and_receive(). After receiving data, the data is compared with the expected data.

• If the check was successful, and the received data matches the expected data, a log message is written with ID ‘config.id_for_bfm’.

• If the received data did not match the expected data, an alert with severity ‘alert_level’ will be reported.

• The procedure will transmit dummy data (0x0) to the DUT.

• The procedure will report alerts for the same conditions and use similar default values as the spi_master_transmit_and_receive() procedure.

• Note that action_between_words only apply for t_slv_array multi-word transfers.

spi_master_check(data_exp(slv), msg, spi_if, [alert_level, [action_when_transfer_is_done, [scope, [msg_id_panel, [config]]]]])
spi_master_check(data_exp(slv_array), msg, spi_if, [alert_level, [action_when_transfer_is_done, [action_between_words, [scope, [msg_id_panel, [config]]]]]])

Object	Name	Dir.	Type	Description
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is ERROR.
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_master_check(x"3B", "Checking data on SPI interface", spi_if);
spi_master_check((x"AA", x"BB"), "Checking data on SPI interface", spi_if, ERROR, RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS,
                 C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_master_check(C_CR_BYTE, "Expecting carriage return");

spi_slave_transmit_and_receive()

Transmits the data in ‘tx_data’ to the DUT and stores the received data in ‘rx_data’, using the SPI protocol. For protocol details, see the SPI specification.

When called, the procedure will wait for next ss_n, or start transfer and receive immediately, depending on the selection of when_to_start_transfer and if ss_n is already set. If terminate_access is ‘1’ when this happens, the transfer and receive will be terminated instead.

• An error is reported if ss_n is not kept low during the entire transmission.

spi_slave_transmit_and_receive(tx_data, rx_data, aborted, msg, spi_if, terminate_access, [aborted_alert_level, [when_to_start_transfer, [scope, [msg_id_panel, [config]]]]])
spi_slave_transmit_and_receive(tx_data, rx_data, msg, spi_if, [terminate_access,] [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
variable	rx_data	out	std_logic_vector t_slv_array	The data value received from the DUT, either a single word or a word array.
variable	aborted	out	boolean	Set to true when the procedure is aborted
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
signal	terminate_access	in	std_logic	Determines if SPI slave transfer is performed. Setting this to ‘1’ before a slave command is executed terminates the command.
constant	aborted_alert_level	in	t_alert_level	Sets the severity for the alert when the procedure is aborted. Default value is ERROR.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_slave_transmit_and_receive(x"AA", v_data_out, "Transmitting and receiving data from peripheral 1", spi_if);
spi_slave_transmit_and_receive((x"AA", x"BB"), v_data_out, "Transmitting and receiving data from peripheral 1", spi_if,
                               terminate_access, START_TRANSFER_ON_NEXT_SS, C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_slave_transmit_and_receive(C_ASCII_A, v_data_out, "Transmitting ASCII A to DUT and receiving data from DUT");

spi_slave_transmit_and_check()

Transmits the data in ‘tx_data’ and receives data from the DUT, using the transmit and receive procedure as described in spi_slave_transmit_and_receive(). After receiving data, the data is compared with the expected data.

• If the check was successful, and the received data matches the expected data, a log message is written with ID ‘config.id_for_bfm’.

• If the received data did not match the expected data, an alert with severity ‘alert_level’ will be reported.

• The procedure will report alerts for the same conditions and use similar default values as the spi_slave_transmit_and_receive() procedure.

spi_slave_transmit_and_check(tx_data, data_exp, msg, spi_if, [terminate_access,] [alert_level, [when_to_start_transfer, [scope, [msg_id_panel, [config]]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
signal	terminate_access	in	std_logic	Determines if SPI slave transfer is performed. Setting this to ‘1’ before a slave command is executed terminates the command.
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is ERROR.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_slave_transmit_and_check(x"AA", x"3B", "Transmitting data and checking received data on SPI interface", spi_if);
spi_slave_transmit_and_check((x"AA", x"BB"), (x"3A", x"3B"), "Transmitting data and checking received data on SPI interface",
                              spi_if, terminate_access, ERROR, START_TRANSFER_ON_NEXT_SS, C_SCOPE, shared_msg_id_panel,
                              C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_slave_transmit_and_check(x"AA", C_CR_BYTE, "Transmitting 0xAA and expecting carriage return");

spi_slave_transmit()

Transmits the data in ‘tx_data’ using the transmit and receive procedure as described in spi_slave_transmit_and_receive().

• The received data from the DUT is ignored.

• The procedure will report alerts for the same conditions and use similar default values as the spi_slave_transmit_and_receive() procedure.

spi_slave_transmit(tx_data(slv), aborted, msg, spi_if, terminate_access, [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])
spi_slave_transmit(tx_data(slv), msg, spi_if, [terminate_access,] [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])
spi_slave_transmit(tx_data(slv_array), msg, spi_if, [terminate_access,] [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])

Object	Name	Dir.	Type	Description
constant	tx_data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
variable	aborted	out	boolean	Set to true when the procedure is aborted
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
signal	terminate_access	in	std_logic	Determines if SPI slave transfer is performed. Setting this to ‘1’ before a slave command is executed terminates the command.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_slave_transmit(x"AA", "Transmitting data to peripheral 1", spi_if);
spi_slave_transmit((x"AA", x"BB"), "Transmitting data to peripheral 1", spi_if, terminate_access, START_TRANSFER_ON_NEXT_SS,
                   C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_slave_transmit(C_ASCII_A, "Transmitting ASCII A to DUT");

spi_slave_receive()

Receives data from the DUT using the transmit and receive procedure as described in spi_slave_transmit_and_receive().

• The procedure will transmit dummy data (0x0) to the DUT.

• The procedure will report alerts for the same conditions and use similar default values as the spi_slave_transmit_and_receive() procedure.

spi_slave_receive(rx_data(slv), aborted, msg, spi_if, terminate_access, [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])
spi_slave_receive(rx_data(slv), msg, spi_if, [terminate_access,] [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])
spi_slave_receive(rx_data(slv_array), msg, spi_if, [terminate_access,] [when_to_start_transfer, [scope, [msg_id_panel, [config]]]])

Object	Name	Dir.	Type	Description
variable	rx_data	out	std_logic_vector t_slv_array	The data value received from the DUT, either a single word or a word array.
variable	aborted	out	boolean	Set to true when the procedure is aborted
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
signal	terminate_access	in	std_logic	Determines if SPI slave transfer is performed. Setting this to ‘1’ before a slave command is executed terminates the command.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_slave_receive(v_data_out, "Receive from Peripheral 1", spi_if);
spi_slave_receive(v_data_out, "Receive from Peripheral 1", spi_if, terminate_access, START_TRANSFER_ON_NEXT_SS, C_SCOPE,
                  shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_slave_receive(v_data_out, "Receive from Peripheral 1");

spi_slave_check()

Receives data from the DUT using the transmit and receive procedure as described in spi_slave_transmit_and_receive(). After receiving data, the data is compared with the expected data.

• If the check was successful, and the received data matches the expected data, a log message is written with ID ‘config.id_for_bfm’.

• If the received data did not match the expected data, an alert with severity ‘alert_level’ will be reported.

• The procedure will transmit dummy data (0x0) to the DUT.

• The procedure will report alerts for the same conditions and use similar default values as the spi_slave_transmit_and_receive() procedure.

spi_slave_check(data_exp, msg, spi_if, [terminate_access,] [alert_level, [when_to_start_transfer, [scope, [msg_id_panel, [config]]]]])

Object	Name	Dir.	Type	Description
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
signal	spi_if	inout	t_spi_if	SPI signal interface record
signal	terminate_access	in	std_logic	Determines if SPI slave transfer is performed. Setting this to ‘1’ before a slave command is executed terminates the command.
constant	alert_level	in	t_alert_level	Sets the severity for the alert. Default value is ERROR.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_BFM_SCOPE (“SPI 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_spi_bfm_config	Configuration of BFM behavior and restrictions. Default value is C_SPI_BFM_CONFIG_DEFAULT.

-- Examples:
spi_slave_check(x"3B", "Checking data on SPI interface", spi_if);
spi_slave_check((x"3A", x"3B"), "Checking data on SPI interface", spi_if, terminate_access, ERROR, START_TRANSFER_ON_NEXT_SS,
                C_SCOPE, shared_msg_id_panel, C_SPI_BFM_CONFIG_DEFAULT);

-- Suggested usage (requires local overload, see 'Local BFM overloads' section):
spi_slave_check(C_CR_BYTE, "Expecting carriage return");

init_spi_if_signals()

Initializes the SPI interface.

Master mode set true:

• ss_n initialized to ‘H’.

• if config.CPOL = ‘1’, sclk initialized to ‘H’. Otherwise, sclk initialized to ‘L’.

• miso and mosi initialized to ‘Z’.

Master mode set false:

• All signals initialized to ‘Z’.

t_spi_if := init_spi_if_signals(config, [master_mode])

Object	Name	Dir.	Type	Description
constant	config	in	t_spi_bfm_config	Configuration of BFM behavior and restrictions
constant	master_mode	in	boolean	Whether the interface is in master or slave mode. Default value is true (master).

-- Examples:
spi_if <= init_spi_if_signals(C_SPI_BFM_CONFIG_DEFAULT);        -- Implicitly master mode since default is 'true'
spi_if <= init_spi_if_signals(C_SPI_BFM_CONFIG_DEFAULT, true);  -- Explicitly indicating master mode
spi_if <= init_spi_if_signals(C_SPI_BFM_CONFIG_DEFAULT, false); -- master_mode is false, i.e., shall act as a slave

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.

spi_master_transmit_and_receive(C_ASCII_A, v_data_out, "Transmitting ASCII A");

rather than

spi_master_transmit_and_receive(C_ASCII_A, v_data_out, "Transmitting ASCII A", spi_if, RELEASE_LINE_AFTER_TRANSFER, C_SCOPE, shared_msg_id_panel, C_SPI_CONFIG_LOCAL);

By defining the local overload as e.g.

procedure spi_master_transmit_and_receive(
  constant tx_data : in  std_logic_vector;
  variable rx_data : out std_logic_vector;
  constant msg     : in  string) is
begin
  spi_master_transmit_and_receive(tx_data,                     -- Keep as is
                                  rx_data,                     -- Keep as is
                                  msg,                         -- Keep as is
                                  spi_if,                      -- Signal must be visible in local process scope
                                  RELEASE_LINE_AFTER_TRANSFER, -- Use default, unless passing SLVs to master in a multi-word transfer
                                  C_SCOPE,                     -- Use the default
                                  shared_msg_id_panel,         -- Use global, shared msg_id_panel
                                  C_SPI_CONFIG_LOCAL);         -- Use locally defined configuration or C_SPI_CONFIG_DEFAULT
end procedure;

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

• 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

Local BFM configuration

The SPI BFM requires that a local configuration is declared in the testbench and used in the BFM procedure calls. The default BFM configuration is defined with a bit period of -1 ns so that the BFM can detect and alert the user that the configuration has not been set.

Defining a local SPI BFM configuration::

constant C_SPI_CONFIG_LOCAL : t_spi_bfm_config := (
  CPOL             => '0',
  CPHA             => '0',
  spi_bit_time     => 200 ns,
  ss_n_to_sclk     => 301 ns,
  sclk_to_ss_n     => 301 ns,
  inter_word_delay => 0 ns,
  match_strictness => MATCH_EXACT,
  id_for_bfm       => ID_BFM,
  id_for_bfm_wait  => ID_BFM_WAIT,
  id_for_bfm_poll  => ID_BFM_POLL
);

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 additional documentation on the SPI protocol, please see the SPI specification, e.g. “ST TN0897 Technical note ST SPI protocol. ID 023176 Rev 2”.

Important

• This is a simplified Bus Functional Model (BFM) for SPI.

• The given BFM complies with the basic SPI protocol and thus allows a normal access towards a SPI interface.

• This BFM is not a SPI protocol checker.

• For a more advanced BFM please contact UVVM support at info@uvvm.org

---

VVC

• VVC functionality is implemented in spi_vvc.vhd

• For general information see VVC Framework - Essential Mechanisms.

Entity

Generics

Name	Type	Default	Description
GC_DATA_WIDTH	natural	8	Bits in the SPI data word
GC_DATA_ARRAY_WIDTH	natural	32	Number of SPI data words in a data word array of type t_slv_array
GC_INSTANCE_IDX	natural	1	Instance number to assign the VVC
GC_MASTER_MODE	boolean	true	Whether the VVC shall act as an SPI master or an SPI slave on the bus
GC_SPI_CONFIG	t_spi_bfm_config	C_SPI_BFM_CONFIG_DEFAULT	Configuration for the SPI 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	spi_vvc_if	inout	t_spi_if	SPI signal interface record

Configuration Record

vvc_config accessible via shared_spi_vvc_config

Record element	Type	Default	Description
inter_bfm_delay	t_inter_bfm_delay	C_SPI_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_spi_bfm_config	C_SPI_BFM_CONFIG_DEFAULT	Configuration for the SPI 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.
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_spi_vvc_config(C_VVC_IDX_MASTER).inter_bfm_delay.delay_in_time := 10 ms;
shared_spi_vvc_config(C_VVC_IDX_SLAVE).bfm_config.CPOL := '1';

Status Record

vvc_status accessible via shared_spi_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.

spi_master_transmit_and_receive()

Adds a master transmit and receive command to the SPI 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 BFM spi_master_transmit_and_receive() procedure.

The received data will not be returned in this procedure call since it is non-blocking for the sequencer/caller, but the received data 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 received data will be sent to the SPI VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench). This procedure can only be called when the SPI VVC is instantiated in master mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘true’.

spi_master_transmit_and_receive(VVCT, vvc_instance_idx, data(slv), [data_routing,] msg, [action_when_transfer_is_done, [scope]])
spi_master_transmit_and_receive(VVCT, vvc_instance_idx, data(slv_array), [data_routing,] msg, [action_when_transfer_is_done, [action_between_words, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_routing	in	t_data_routing	Selects the destination of the received data
constant	msg	in	string	A custom message to be appended in the log/alert
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_master_transmit_and_receive(SPI_VVCT, 0, x"AF", "SPI Master Tx and Rx to/from Peripheral 1. Rx data will be stored in VVC to be retrieved later using fetch_result.");
spi_master_transmit_and_receive(SPI_VVCT, 0, x"AF", TO_SB, "SPI Master Tx and Rx to/from Peripheral 1. Rx data will be sent to the SPI 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 read.
...
spi_master_transmit_and_receive(SPI_VVCT, 0, (x"AB", x"CD"), "Transmitting two bytes to Peripheral 1 and receiving from Peripheral 1");
v_cmd_idx := get_last_received_cmd_idx(SPI_VVCT, 0);
await_completion(SPI_VVCT, 0, v_cmd_idx, 1 us, "Wait for transmit and receive to finish");
fetch_result(SPI_VVCT, 0, v_cmd_idx, v_result, "Fetching first byte from transmit and receive operation");
fetch_result(SPI_VVCT, 0, v_cmd_idx, v_result, "Fetching second byte from transmit and receive operation");

Hint

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

spi_master_transmit_only()

Adds a master transmit command to the SPI 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 BFM spi_master_transmit() procedure.

This procedure will ignore the received data from the slave DUT. This procedure can only be called when the SPI VVC is instantiated in master mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘true’.

spi_master_transmit_only(VVCT, vvc_instance_idx, data(slv), msg, [action_when_transfer_is_done, [scope]])
spi_master_transmit_only(VVCT, vvc_instance_idx, data(slv_array), msg, [action_when_transfer_is_done, [action_between_words, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_master_transmit_only(SPI_VVCT, 0, x"0D", "Transmitting carriage return to Peripheral 1");
spi_master_transmit_only(SPI_VVCT, 0, (x"AA", x"BB"), "Transmitting carriage return to Peripheral 1",
                         RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS, C_SCOPE);

spi_master_receive_only()

Adds a master receive command to the SPI 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 BFM spi_master_receive() procedure.

The procedure will transmit dummy data (0x0) to the DUT. The received data will not be returned in this procedure call since it is non-blocking for the sequencer/caller, but the received data will be stored in the VVC for a potential future fetch (see example with fetch_result below). When receiving multiple words, each word must be fetched separately with the same command index. If the data_routing is set to TO_SB, the received data will be sent to the SPI VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench). This procedure can only be called when the SPI VVC is instantiated in master mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘true’.

spi_master_receive_only(VVCT, vvc_instance_idx, [data_routing,] msg, [num_words, [action_when_transfer_is_done, [action_between_words, [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	data_routing	in	t_data_routing	Selects the destination of the received data
constant	msg	in	string	A custom message to be appended in the log/alert
constant	num_words	in	positive	Number of words that shall be received. Default value is 1.
constant	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_master_receive_only(SPI_VVCT, 0, "Receiving from Peripheral 1. Rx data will be stored in VVC to be retrieved later using fetch_result.");
spi_master_receive_only(SPI_VVCT, 0, TO_SB, "Receiving 6 words from Peripheral 1. Rx data will be sent to the SPI scoreboard for checking.", 6);

-- 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 read.
...
spi_master_receive_only(SPI_VVCT, 0, "Receiving from Peripheral 1");
v_cmd_idx := get_last_received_cmd_idx(SPI_VVCT, 0);
await_completion(SPI_VVCT, 0, v_cmd_idx, 1 us, "Wait for receive to finish");
fetch_result(SPI_VVCT, 0, 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.

spi_master_transmit_and_check()

Adds a master transmit and check command to the SPI 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 BFM spi_master_transmit_and_check() procedure.

This procedure can only be called when the SPI VVC is instantiated in master mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘true’.

spi_master_transmit_and_check(VVCT, vvc_instance_idx, data(slv), data_exp(slv), msg, [alert_level, [action_when_transfer_is_done, [scope]]])
spi_master_transmit_and_check(VVCT, vvc_instance_idx, data(slv_array), data_exp(slv_array), msg, [alert_level, [action_when_transfer_is_done, [action_between_words, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
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	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_master_transmit_and_check(SPI_VVCT, 0, x"0D", x"5F", "Transmitting carriage return to Peripheral 1 and expecting data back");
spi_master_transmit_and_check(SPI_VVCT, 0, C_CR_BYTES, C_EXP_BYTES, "Transmitting carriage return to Peripheral 1 and expecting data back",
                              ERROR, RELEASE_LINE_AFTER_TRANSFER, HOLD_LINE_BETWEEN_WORDS, C_SCOPE);

spi_master_check_only()

Adds a master check command to the SPI 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 BFM spi_master_check() procedure.

The procedure will transmit dummy data (0x0) to the DUT. This procedure can only be called when the SPI VVC is instantiated in master mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘true’.

spi_master_check_only(VVCT, vvc_instance_idx, data_exp(slv), msg, [alert_level, [action_when_transfer_is_done, [scope]]])
spi_master_check_only(VVCT, vvc_instance_idx, data_exp(slv_array), msg, [alert_level, [action_when_transfer_is_done, [action_between_words, [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	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
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	action_when_transfer_is_done	in	t_action_when_transfer_is_done	Whether or not the SPI master method shall release or hold ss_n after the operation is finished. Default value is RELEASE_LINE_AFTER_TRANSFER.
constant	action_between_words	in	t_action_between_words	Whether or not the SPI master method shall release or hold ss_n between words when transmitting a word array. Default value is HOLD_LINE_BETWEEN_WORDS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_master_check_only(SPI_VVCT, 0, x"0D", "Expecting carriage return from Peripheral 1");
spi_master_check_only(SPI_VVCT, 0, C_CR_BYTE, "Expecting carriage return from Peripheral 1", ERROR, RELEASE_LINE_AFTER_TRANSFER,
                      HOLD_LINE_BETWEEN_WORDS, C_SCOPE);

spi_slave_transmit_and_receive()

Adds a slave transmit and receive command to the SPI 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 BFM spi_slave_transmit_and_receive() procedure.

The received data will not be returned in this procedure call since it is non-blocking for the sequencer/caller, but the received data 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 received data will be sent to the SPI VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench). This procedure can only be called when the SPI VVC is instantiated in slave mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘false’.

spi_slave_transmit_and_receive(VVCT, vvc_instance_idx, data, [data_routing,] msg, [when_to_start_transfer, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_routing	in	t_data_routing	Selects the destination of the received data
constant	msg	in	string	A custom message to be appended in the log/alert
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_slave_transmit_and_receive(SPI_VVCT, 0, x"0D", "Transmitting carriage return to Peripheral 1 and receiving data back");
spi_slave_transmit_and_receive(SPI_VVCT, 0, x"0D", TO_SB, "Transmitting carriage return to Peripheral 1 and receiving data back",
                               START_TRANSFER_ON_NEXT_SS, C_SCOPE);

-- 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 read.
...
spi_slave_transmit_and_receive(SPI_VVCT, 0, (x"AB", x"CD"), "Transmitting two bytes to Peripheral 1 and receiving from Peripheral 1");
v_cmd_idx := get_last_received_cmd_idx(SPI_VVCT, 0);
await_completion(SPI_VVCT, 0, v_cmd_idx, 1 us, "Wait for transmit and receive to finish");
fetch_result(SPI_VVCT, 0, v_cmd_idx, v_result, "Fetching first byte from transmit and receive operation");
fetch_result(SPI_VVCT, 0, v_cmd_idx, v_result, "Fetching second byte from transmit and receive operation");

Hint

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

spi_slave_transmit_only()

Adds a slave transmit command to the SPI 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 BFM spi_slave_transmit() procedure.

This procedure will ignore the received data from the master DUT. This procedure can only be called when the SPI VVC is instantiated in slave mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘false’.

spi_slave_transmit_only(VVCT, vvc_instance_idx, data, msg, [when_to_start_transfer, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	msg	in	string	A custom message to be appended in the log/alert
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_slave_transmit_only(SPI_VVCT, 0, x"0D", "Transmitting carriage return to Peripheral 1");
spi_slave_transmit_only(SPI_VVCT, 0, x"0D", "Transmitting carriage return to Peripheral", START_TRANSFER_ON_NEXT_SS, C_SCOPE);

spi_slave_receive_only()

Adds a slave receive command to the SPI 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 BFM spi_slave_receive() procedure.

The procedure will transmit dummy data (0x0) to the DUT. The received data will not be returned in this procedure call since it is non-blocking for the sequencer/caller, but the received data will be stored in the VVC for a potential future fetch (see example with fetch_result below). When receiving multiple words, each word must be fetched separately with the same command index. If the data_routing is set to TO_SB, the received data will be sent to the SPI VVC dedicated scoreboard where it will be checked against the expected value (provided by the testbench). This procedure can only be called when the SPI VVC is instantiated in slave mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘false’.

spi_slave_receive_only(VVCT, vvc_instance_idx, [data_routing,] msg, [num_words, [when_to_start_transfer, [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	data_routing	in	t_data_routing	Selects the destination of the received data
constant	msg	in	string	A custom message to be appended in the log/alert
constant	num_words	in	positive	Number of words that shall be received. Default value is 1.
constant	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_slave_receive_only(SPI_VVCT, 0, "Receiving from Peripheral 1");
spi_slave_receive_only(SPI_VVCT, 0, TO_SB, "Receiving from Peripheral 1", 6, START_TRANSFER_ON_NEXT_SS, C_SCOPE);

-- 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 read.
...
spi_slave_receive_only(SPI_VVCT, 0, "Receiving from Peripheral 1");
v_cmd_idx := get_last_received_cmd_idx(SPI_VVCT, 0);
await_completion(SPI_VVCT, 0, v_cmd_idx, 1 us, "Wait for receive to finish");
fetch_result(SPI_VVCT, 0, 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.

spi_slave_transmit_and_check()

Adds a slave transmit and check command to the SPI 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 BFM spi_slave_transmit_and_check() procedure.

This procedure can only be called when the SPI VVC is instantiated in slave mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘false’.

spi_slave_transmit_and_check(VVCT, vvc_instance_idx, data, data_exp, msg, [alert_level, [when_to_start_transfer, [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	data	in	std_logic_vector t_slv_array	The data value to be transmitted to the DUT, either a single word or a word array.
constant	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
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	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_slave_transmit_and_check(SPI_VVCT, 0, x"0D", x"5F", "Transmitting carriage return to Peripheral 1 and expecting data back");
spi_slave_transmit_and_check(SPI_VVCT, 0, (x"AA", x"BB"), (x"3A", x"3B"), "Transmitting carriage return to Peripheral 1 and expecting data back",
                             ERROR, START_TRANSFER_IMMEDIATE, C_SCOPE);

spi_slave_check_only()

Adds a slave check command to the SPI 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 BFM spi_slave_check() procedure.

The procedure will transmit dummy data (0x0) to the DUT. This procedure can only be called when the SPI VVC is instantiated in slave mode, i.e. setting the VVC entity generic constant ‘GC_MASTER_MODE’ to ‘false’.

spi_slave_check_only(VVCT, vvc_instance_idx, data_exp, msg, [alert_level, [when_to_start_transfer, [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	data_exp	in	std_logic_vector t_slv_array	The data value to expect when receiving data from the DUT, either a single word or a word array.
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	when_to_start_transfer	in	t_when_to_start_transfer	Determines if SPI slave shall wait for next ss_n if a transfer has already started. Default value is START_TRANSFER_ON_NEXT_SS.
constant	scope	in	string	Describes the scope from which the log/alert originates. Default value is C_VVC_CMD_SCOPE_DEFAULT.

-- Examples:
spi_slave_check_only(SPI_VVCT, 0, x"0D", "Expecting carriage return from Peripheral 1");
spi_slave_check_only(SPI_VVCT, 0, (x"3A", x"3B"), "Expecting carriage return from Peripheral 1", ERROR, START_TRANSFER_IMMEDIATE, 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.

SPI transaction info record fields. Transaction Type: t_base_transaction (BT) - accessible via shared_spi_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
data	t_slv_array(31 downto 0)(31 downto 0)	0x0	The data to be transmitted
data_exp	t_slv_array(31 downto 0)(31 downto 0)	0x0	The expected data to be received
num_words	natural	0	Number of words that shall be received
word_length	natural	0	Length of words to be sent or received
when_to_start_transfer	t_when_to_start_transfer	START_TRANSFER_IMMEDIATE	Determines if SPI slave shall wait for next ss_n if a transfer has already started
action_when_transfer_is_done	t_action_when_transfer_is_done	RELEASE_LINE_AFTER_TRANSFER	Determines if SPI master shall release or hold ss_n after the transfer is done
action_between_words	t_action_between_words	HOLD_LINE_BETWEEN_WORDS	Determines if SPI master shall release or hold ss_n between words when transmitting a word 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. spi_master_receive_only(). 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 SPI scoreboard is accessible from the testbench as a shared variable SPI_VVC_SB, located in the vvc_methods_pkg.vhd, e.g.

SPI_VVC_SB.add_expected(C_SPI_VVC_IDX, pad_spi_sb(v_expected), "Adding expected");

The SPI scoreboard is per default a 32 bits wide standard logic vector. When sending expected data to the scoreboard, where the data width is smaller than the default scoreboard width, we recommend zero-padding the data with the pad_spi_sb() function, e.g.

SPI_VVC_SB.add_expected(<SPI VVC instance number>, pad_spi_sb(<exp 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 SPI VVC scoreboard using the SPI_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_spi_vvc_config(C_VVC_INDEX).unwanted_activity_severity := NO_ALERT;

For SPI 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 SPI 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

• SPI BFM

Before compiling the SPI 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 SPI VVC

Compile to library	File	Comment
bitvis_vip_spi	spi_bfm_pkg.vhd	SPI BFM
bitvis_vip_spi	transaction_pkg.vhd	SPI transaction package with DTT types, constants, etc.
bitvis_vip_spi	vvc_cmd_pkg.vhd	SPI VVC command types and operations
bitvis_vip_spi	../uvvm_vvc_framework/src_target_dependent/td_target_support_pkg.vhd	UVVM VVC target support package, compiled into this VVC library
bitvis_vip_spi	../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_spi	vvc_sb_pkg.vhd	SPI VVC scoreboard
bitvis_vip_spi	vvc_methods_pkg.vhd	SPI VVC methods
bitvis_vip_spi	../uvvm_vvc_framework/src_target_dependent/td_queue_pkg.vhd	UVVM queue package for this VVC
bitvis_vip_spi	../uvvm_vvc_framework/src_target_dependent/td_vvc_entity_support_pkg.vhd	UVVM VVC entity support compiled into this VVC library
bitvis_vip_spi	spi_vvc.vhd	SPI VVC
bitvis_vip_spi	vvc_context.vhd	SPI 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 additional documentation on the SPI protocol, please see the SPI specification, e.g. “ST TN0897 Technical note ST SPI protocol. ID 023176 Rev 2”.

Important

• This is a simplified Verification IP (VIP) for SPI.

• The given VIP complies with the basic SPI protocol and thus allows a normal access towards a SPI interface.

• This VIP is not a SPI 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.