Avalon Verification IP Suite User Guide

RSS

UG-01073 | 2016.12.13

Introduction to Avalon Verification IP Suite

The Avalon^®Verification IP Suite provides bus functional models (BFMs) to simulate the behavior and facilitate the verification of IP. The Verification IP Suite includes BFMs for the following interfaces and components:

Avalon Memory-Mapped (Avalon-MM) master and slave interfaces
Avalon Streaming (Avalon-ST) source and sink interfaces
Conduit interfaces and Avalon Tri-State conduit (Avalon-TC) interfaces
Clock source and reset source
Interrupt source and sink
Custom instruction master and slave
External memory

This suite also provides the following monitors to verify the respective Avalon protocols:

Avalon-MM monitor
Avalon-ST monitor

Advantages of Using BFMs and Monitors

Using these BFMs and monitors has the following advantages:

It accelerates the verification process by providing key components of the verification testbench.
It provides Avalon BFM components that implement the standard Avalon-MM and Avalon-ST protocols, serving as a reference for those protocols.
For SystemVerilog users, the verification suite provides a platform that you can use to implement constraint-driven randomized tests. For example, you can implement the following modules for random testing:
- Traffic scenario drivers
- Scoreboard and coverage facilities
- Assertion checkers

BFM Implementation

Most components in the Avalon Verification IP Suite BFMs are implemented in SystemVerilog. The exceptions are the Clock Source and Reset Source BFMs that are written in VHDL. The BFM components use primarily Verilog HDL with a few basic SystemVerilog constructs that are supported by ModelSim^® - Intel FPGA Edition.

The Quartus II software version 13.0 and higher extends VHDL BFM support in Qsys. The VHDL BFMs wrap the SystemVerilog implementation and include additional logic to support VDHL.

Table 1. BFM Language Support
BFM	Verilog HDL Support	VHDL Support
Clock Source and Reset Source	Yes	Yes
Avalon Interrupt Source and Sink	Yes	Version 13.0 and higher
Avalon-MM Master, Slave, and Monitor	Yes	Version 13.0 and higher
Avalon-ST Source, Sink, and Monitor	Yes	Version 13.0 and higher
Conduit and Tri-State Conduit	Yes	Version 14.0 and higher
External Memory	Yes	Version 13.0 and higher
Nios II Custom Instruction Master and Slave	Yes	Version 13.0 and higher

The VHDL BFM has four parts as shown in the figure below.

SystemVerilog BFM—Contains the BFM implementation and behavioral model, and the SystemVerilog API. The SystemVerilog code is IEEE encrypted for use in single-language simulators.
VHDL package—Provides the VHDL API used to control the BFM and interface with your test program. The package contains VHDL procedures and events.
API handler logic—SystemVerilog logic block that translates your test program’s VHDL API calls to SystemVerilog API calls. The SystemVerilog code is IEEE encrypted for use in single-language simulators.
API communication interface—Bridges the VHDL API to the API handler logic.
Figure 1. VHDL Component BFM

The monitor components use the SystemVerilog Assertion (SVA) language and are supported only by simulators that support SVA, including:

ModelSim^® - Intel FPGA Edition
Synopsys VCS
Mentor Graphics^® Questa.

Application Programming Interface

Intel provides you with a set of application programming interfaces (API) for each Avalon Verification IP Suite BFM. You can use the APIs to construct, instantiate, control, and query signals in all BFM components. Your test programs must use only these public access methods and events to communicate with each BFM.

Note: You can design custom verification environments that do not take advantage of the API. However, Altera does not guarantee continued support or backwards compatibility custom methods.

Application Example of BFMs

The figure below shows an Avalon-MM design with the following components:

An Avalon-MM device under test (DUT) that includes both Avalon-MM master and slave interfaces
An Avalon-ST DUT that includes both source and sink interfaces, although typical components might include a single Avalon interface.

This figure illustrates it is possible to write a testbench using a traditional VerilogHDL implementation or using SystemVerilog with VMM.

Figure 2. Avalon Verification IP Suite Testbench for Avalon-MM and Avalon-ST Interfaces

To verify a component with Avalon-MM interfaces, insert a monitor between the master BFM and the slave interface. To verify a component with Avalon-ST interfaces, insert a monitor between the source BFM and sink interface. You can insert a second monitor between the slave or sink BFM and the master or source interface of the DUT. You can inserted monitors anywhere in the system to provide protocol assertion checking and functional coverage reporting.

The test program drives the stimulus to the DUTs. The test program also determines whether the DUT behavior is correct, by analyzing the responses. The BFMs translate the test program stimuli. The BFMs create the signaling for the Avalon-MM and Avalon-ST protocols. The monitors verify Avalon protocol compliance and provide test coverage reports.

Clock Source BFM

The Avalon Verification IP Suite includes a Clock Source BFM that you can use to generate a clock signal for your testbench.

Note: The Clock Source BFM is only supported in Qsys.

Parameters

Table 2. Clock Source BFM Parameter Settings
Option	Default Value	Legal Values	Description
Clock rate	10	N/A	Specifies the clock rate in MHz.

Clock Source API

clock_start()

Prototype:	`clock_start`()
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Turns on the clock.
Language Support:	Verilog HDL

Clock_stop()

Prototype:	`clock_stop()`
Arguments:	Verilog HDL: None VHDL: None
Returns:	`void`
Description:	Turns off the clock.
Language support:	Verilog HDL, VHDL

get_run_state()

Prototype:	`get_run_state()`
Arguments:	Verilog HDL: None VHDL: None
Returns:	`bit`
Description:	Returns the state of the clock source; 1=running, 0=stop.
Language support:	Verilog HDL, VHDL

get_version()

Prototype:	`string get_version()`
Arguments:	Verilog HDL: None VHDL: None
Returns:	`string`
Description:	Returns BFM version as a string of three integers separated by periods. For example, version 10.1 sp1 is encoded as "10.1.1".
Language support:	Verilog HDL, VHDL

Reset Source BFM

The Avalon Verification IP Suite includes a Reset Source BFM that you can use to generate a reset signal in your testbench.

Parameters

Table 3. Reset Source BFM Parameter Settings
Option	Default Value	Legal Values	Description
Assert reset high	On	On/Off	Specifies the polarity of the reset signal. Turn on this option to set the reset signal active high.
Cycles of initial reset	0	N/A	Specifies the number of cycles that the reset signal is asserted at the initial stage of the simulation.

Reset Source API

reset_assert

Prototype:	`reset_assert`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void.`
Description:	Asserts the reset signal.
Language support:	Verilog HDL

reset_deassert

Prototype:	`reset_deassert`
Arguments:	Verilog HDL: None VHDL: None
Returns:	`void.`
Description:	Deasserts the reset signal.
Language support:	Verilog HDL, VHDL

get_version()

Prototype:	`string get_version()`
Arguments:	Verilog HDL: None VHDL: None
Returns:	`String`.
Description:	Returns BFM version as a string of three integers separated by periods. For example, version 10.1 sp1 is encoded as "10.1.1".
Language support:	Verilog HDL, VHDL

Avalon Interrupt Source and Interrupt Sink BFMs

The Avalon Verification IP Suite includes Avalon Interrupt Source and Avalon Interrupt Sink BFMs for you to generate interrupt signals in your testbench.

Parameters

Table 4. Clock Source BFM Parameter Settings
Option	Default Value	Legal Values	Description
Interrupt Source
Assert IRQ high	On	On/Off	Specifies the polarity of the interrupt source signal. Turn on this option to change the name of the interrupt source signal port from `irq` to `irq_n`.
IRQ width	1	1–32	Specifies the width of the interrupt source signal.
Asynchronous IRQ	Off	On/Off	Specifies whether the interrupt signal is asserted or deasserted immediately after an API call or one clock cycle after an API call. Turn on this option to allow changes to the interrupt signal immediately after an API call. Turn off this option to allow changes to the interrupt signal on the next clock edge.
VHDL BFM ID	0	1–1023	For VHDL BFMs only. Use this option to assign a unique number to each BFM in the testbench design.
Interrupt Sink
Assert IRQ high	On	On/Off	Specifies the polarity of the interrupt sink signal. Turn on this option to change the name of the interrupt source signal port from `irq` to `irq_n`.
IRQ width	1	1–32	Specifies the width of the interrupt source signal.

Interrupt Source and Sink API

clear_irq()

Prototype:	`int clear_irq()`
Arguments:	Verilog HDL: `interrupt_bit` VHDL: `interrupt_bit`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Asserts the interrupt signal and sets the interrupt signal to 0, regardless of the value you set for Assert IRQ high in the parameter editor.
Language Support:	Verilog HDL, VHDL

get_irq()

Prototype:	`get_irq()`
Arguments:	Verilog HDL: None VHDL: `irq`, `bfm_id`, `req_if(bfm_id)`
Returns:	`logic[AV_IRQ_W-1:0]void`
Description:	Returns the current value of the register holding the latched interrupt signal.
Language Support:	Verilog HDL, VHDL

get_version()

Prototype:	`string get_version()`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`String`
Description:	Returns BFM version as a string of three integers separated by periods. For example, version 13.1 sp1 is encoded as "13.1.1".
Language Support:	Verilog HDL

set_irq()

Prototype:	`set_irq()`
Arguments:	Verilog HDL: `int interrupt_bit` VHDL: `int interrupt_bit`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Asserts the interrupt signal and sets the interrupt signal to 1, regardless of the value you set for Assert IRQ high in the parameter editor.
Language Support:	Verilog HDL, VHDL

Avalon-MM Master BFM

The Avalon-MM Master BFM implements the Avalon-MM interface protocol, including: read, write, burst read, and burst write. The figure below shows the top-level modules for a testbench using the Avalon-MM BFM to verify an Avalon-MM slave component. The typical testbench includes the following components:

The Avalon-MM Master BFM
A test program
The DUT that includes an Avalon-MM slave interface

Using the Avalon-MM BFM has the following advantage. It highlights any misinterpretation of the Avalon-MM protocol that might be missed in a testbench designed by a single engineer.

Note: The BFMs allow illegal transactions so that you can test the error-handling functionality of your DUT. Consequently, the BFMs cannot be relied upon to guarantee protocol compliance. The Avalon Monitor components verify protocol compliance.

Figure 3. Top-Level Module to Verify an Avalon-MM Slave Device

Timing

The following timing diagram illustrates the sequence of events for an Avalon-MM Master BFM. The Master BFM drives interleaved writes and reads when the readdatavalid signal is present. This diagram serves as a reference for the following discussion of API and events.

Figure 4. Avalon-MM Master Driving Interleaved Write and Read Transactions

Table 5. Key to the Annotations. The following table lists the annotations used in the figure.
Symbol	Description
T_init	The initial command latency, which is two cycles for transactions 1 and 2. This time is set by the API command `set_command_init_latency`.
T_{wt_1}	The response wait time, which is three cycles. This time is determined by the number of cycles that the `waitrequest` signal is asserted by the slave.The program gets this value using the `get_response_wait_time` command.
T_wr	`waitrequest` is always sampled #1 after the falling edge of `clk`.
T_idle	The idle time after each transaction. This time is set by the command `set_command_idle.`
T_{rl_1}	The response latency for the first read, which is 3 cycles. This is the time between the read command acceptance and the read response provided by the slave. The program gets this time using the `get_response_latency` command. If an Avalon-MM slave component defines the `readLatency` interface property, the `readdatavalid` signal is not used. The `readdatavalid`signal is not necessary because the slave component has a fixed read latency. For more information refer to the Avalon Interface Specifications.
T_{rl_2}	The response latency for the second read, which is 3 cycles. The program gets this time using the `get_response_latency` command.
T_{wrl_1}	The write response latency for the first write, which is 3 cycles. This is the time between when the write command acceptance and the write response is provided by the slave. The program gets this time using the `get_response_latency` command.
S_{ci_1}–S_{ci_4}	Signals when write or read commands are presented on the interface. The event name is `signal_command_issued`.
S_{rc_1},S_{rc_3}	Signals write responses. The event name is `signal_response_complete.`
S_{rc_2},S_{rc_4}	Signals read responses. The event name is `signal_response_complete.`
S_atc	Signals the end of the test. The event name is `signal_all_transactions_complete`
T_{ID_1}–T_{ID_4}	Reference number to identify each read or write transaction.
ID_1, ID_3	Reference number to identify each write transaction.
ID_2, ID_4	Reference number to identify each read transaction.

Figure 5. Avalon-MM Master Driving Write and Read Transactions with No readdatavalid Signal. The timing in the following figure shows the sequence of events for an Avalon-MM Master BFM. The Avalon-MM Master BFM drives a write followed by a read when the readdatavalid signal is not present.

Table 6. Key to the Annotations . The following table lists the annotations used in this figure.
Symbol	Description
T_init	The initial command latency, which is 2 cycles for transactions 1 and 2. This time is set by the API command `set_command_init_latency`.
T_{wt_1}	The response wait time, which is 3 cycles. This time is determined by the number of cycles that the `waitrequest` signal is asserted by the slave.The program gets this value using the `get_response_wait_time` command.
T_{wt_2}	The response wait time for the first read, which is 2 cycles. This time is determined by the number of cycles that the `waitrequest` signal is asserted by the slave.The program gets this value using the `get_response_wait_time` command.
T_wr	`waitrequest` is always sampled #1 after the falling edge of `clk`.
T_idle	The idle time after a transaction. This time is set by the command `set_command_idle.`
S_{ci_1}–S_{ci_2}	Signals when write and read commands are presented on the interface. The event name is `signal_command_issued`.
S_{rc_1}	Signals the first read response. The event name is `signal_response_complete.`
S_atc	Signals the end of the test. The event name is `signal_all_transactions_complete.`

Block Diagram

The following figure provides a block diagram of the Avalon-MM Master BFM. As this figure illustrates, the BFM includes the following major blocks:

Avalon-MM Master API—Provides methods to create Avalon-MM transactions and query the state of all queues.
Command Descriptor—Accumulates the fields of an Avalon-MM command transaction using the set_command API call. Inserts completed commands onto the pending command queue.
Avalon-MM Interface Driver—Issues transfers to the system interconnect fabric and holds each transfer until waitrequest is deasserted. For burst transfers, there is a separate transfer for each word of the burst. The system interconnect fabric can assert waitrequest for each word of the burst, as necessary.
Timestamp Counter—Records a timestamp with commands for use in timing calculations. The driver and monitor both use the timestamp counter for timing calculations.
Avalon-MM Interface Monitor—Monitors the system interconnect fabric and records responses for read transfers in the response queue.
Response Descriptor—Collects information about completed transactions using the get_response_<rolename> API calls. The testbench uses this information for further analysis.
Public Events—Provides status response that arrives together with the data. The public event signals indicate the status of the Master’s request, such as successful completion, timeout, or error.
Figure 6. Block Diagram of the Avalon-MM Master BFM

Parameters

The Avalon-MM BFM supports the full range of signals defined for the Avalon-MM master interface. You can customize the Avalon-MM master interface using the parameters described in the following table.

Table 7. Parameters for the Avalon-MM Master BFM
Parameter	Default Value	Legal Values	Description
Port Widths
Address width	32	N/A	Address width in bits.
Symbol width	8	N/A	Data symbol width in bits. The symbol width should be 8 for byte-oriented interfaces.
Read Response width	8	N/A	Read response signal width in bits.
Write Response width	8	N/A	Write response signal width in bits.
Parameters
Number of symbols	4	N/A	Number of symbols per word.
Burstcount width	3	N/A	The width of the burst count in bits.
Port Enables
Use the read signal	On	On/Off	When On, the interface includes a `read` pin.
Use the write signal	On	On/Off	When On, the interface includes a `write` pin.
Use the address signal	On	On/Off	When On, the interface includes `address` pins.
Use the byteenable signal	On	On/Off	When On, the interface includes `byteenable` pins.
Use the burstcount signal	On	On/Off	When On, the interface includes `burstcount` pins.
Use the readdata signal	On	On/Off	When On, the interface includes a `readdata` pin.
Use the readdatavalid signal	On	On/Off	When On, the interface includes a `readdatavalid` pin.
Use the writedata signal	On	On/Off	When On, the interface includes a `writedata` pin.
Use the begintransfer signal	Off	On/Off	When On, the interface includes `writedata` pins
Use the beginbursttransfer signal	Off	On/Off	When On, the interface includes a `beginbursttransfer` pins.
Use the arbiterlock signal	Off	On/Off	When On, the interface includes an `arbiterlock` pin.
Use the lock signal	Off	On/Off	When On, the interface includes a `lock` pin.
Use the debugaccess signal	Off	On/Off	When On, the interface includes a `debugaccess` pin.
Use the waitrequest signal	On	On/Off	When On, the interface includes a `waitrequest` pin.
Use the transactionid signal	Off	On/Off	When On, the interface includes a `transactionid` pin.
Use the write response signals	Off	On/Off	When On, the interface includes a `writeresponse` pin.
Use the read response signals	Off	On/Off	When On, the interface includes a `readresponse` pin.
Use the clken signals	Off	On/Off	When On, the interface includes a `clken` pin.
Port Polarity
Assert reset high	On	On/Off	When On, `reset` is asserted high.
Assert waitrequest high	On	On/Off	When On, `waitrequest` is asserted high.
Assert read high	On	On/Off	When On, `read` is asserted high.
Assert write high	On	On/Off	When On, `write` is asserted high.
Assert byteenable high	On	On/Off	When On, `byteenable` is asserted high.
Assert readdatavalid high	On	On/Off	When On, `readdatavalid` is asserted high.
Assert arbiterlock high	On	On/Off	When On, `arbiterlock` is asserted high.
Assert lock high	On	On/Off	When On, `lock` is asserted high.
Burst Attributes
Linewrap burst	On	On/Off	When On, the address for bursts wraps instead of incrementing. With a wrapping burst, when the address reaches a burst boundary, it wraps back to the previous burst boundary. Consequently, only the low order bits are used for addressing.
Burst on burst boundaries only	On	On/Off	When On, memory bursts are aligned to the address size.
Miscellaneous
Maximum pending reads	1	N/A	The maximum number of pending reads that can be queued by the slave.
Fixed read latency (cycles)	1	N/A	Sets the read latency for fixed-latency slaves. Not used on interfaces that include the `readdatavalid` signal.
VHDL BFM ID	0	0–1023	For VHDL BFMs only. Use this option to assign a unique number to each BFM in the testbench design.
Timing
Fixed read wait time (cycles)	1	N/A	For master interfaces that do not use the `waitrequest` signal. The read wait time indicates the number of cycles before the master responds to a read. The timing is as if the master asserted `waitrequest` for this number of cycles.
Fixed write wait time (cycles)	0	N/A	For master interfaces that do not use the `waitrequest` signal. The write wait time indicates the number of cycles before the master accepts a write.
Registered waitrequest	Off	On/Off	Specifies whether to turn on the register stage.
Registered Incoming Signals	Off	On/Off	Specifies whether to register incoming signals.
Interface Address Type
Set master interface address type to symbols or words	WORDS	WORDS/SYMBOLS	Sets slave interface address type to symbols or words.

Avalon-MM Master BFM API

all_transactions_complete()

Prototype:	`bit all_()`
Arguments:	Verilog HDL: None VHDL:`transactions_complete_status`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`.
Description:	Queries the BFM component to determine whether all issued commands have been completed. A return value of 1 means that there are no more transactions in the transaction queue or in progress.
Language support:	Verilog HDL, VHDL

event_all_transactions_complete()

Prototype:	`event_all_transactions_complete()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that all commands have completed.
Language support:	VHDL

event_command_issued()

Prototype:	`event_command_issued()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench a command was driven to the bus.
Language support:	VHDL

event_max_command_queue_size()

Prototype:	`event_max_command_queue_size()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that the command queue size reached its maximum limit.
Language support:	VHDL

event_min_command_queue_size()

Prototype:	`event_min_command_queue_size()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that the command queue size reached its minimum limit.
Language support:	VHDL

event_read_response_complete()

Prototype:	`event_read_response_complete()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that a read response was received.
Language support:	VHDL

event_response_complete()

Prototype:	`event_response_complete()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that a read/write response was received.
Language support:	VHDL

event_write_response_complete()

Prototype:	`event_write_response_complete()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that a write response was received.
Language support:	VHDL

get_command_issued_queue_size()

Prototype:	`int get_command_issued_queue_size()`
Arguments:	Verilog HDL: None VHDL: `command_issued_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the issued command queue to determine the number of commands that have been driven to the system interconnect fabric, but not completed.
Language support:	Verilog HDL, VHDL

get_command_pending_queue_size()

Prototype:	`int get_command_pending_queue_size()`
Arguments:	Verilog HDL: None VHDL: `command_pending_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the command queue to determine number of pending commands waiting to be driven out as Avalon requests.
Language support:	Verilog HDL, VHDL

get_read_response_queue_size()

Prototype:	`int get_read_response_queue_size()`
Arguments:	Verilog HDL: None VHDL: `read_response_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the read response queue to determine number of response descriptors currently stored in the BFM. This is the number of responses the test program can immediately remove from the response queue for further processing.
Language support:	Verilog HDL, VHDL

get_response_address()

Prototype:	`bit [AV_ADDRESS_W-1:0] get_response_address()`
Arguments:	Verilog HDL: None VHDL: `response_address`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Returns the transaction address in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_byte_enable()

Prototype:	`bit [AV_NUMSYMBOLS-1:0] get_response_byte_enable(int index)`
Arguments:	Verilog HDL: `index` VHDL: `response_byte_enable`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Returns the value of the byte enables in the response descriptor that has been removed from the response queue. Each cycle of a burst response is addressed individually by the specified index.
Language support:	Verilog HDL, VHDL

get_response_burst_size()

Prototype:	`bit [AV_BURSTCOUNT_W-1:0]get_response_burst_size()`
Arguments:	Verilog HDL: None VHDL: `response_burst_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Returns the size of the response transaction burst count in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_data()

Prototype:	`bit [AV_DATA_W-1:0] get_response_data(int index)`
Arguments:	Verilog HDL: `index` VHDL: `response_data`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Returns the transaction read data in the response descriptor that has been removed from the response queue. Each cycle in a burst response is addressed individually by the specified index. In the case of read responses, the data is the data captured on the `avm_readdata` interface pin. In the case of write responses, the data on the driven `avm_writedata` pin is captured and reflected here.
Language support:	Verilog HDL, VHDL

get_response_latency()

Prototype:	`int get_response_latency(int index)`
Arguments:	Verilog HDL: `index` VHDL: `response_data`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Returns the transaction read latency in the response descriptor that has been removed from the response queue. Each cycle in a burst read has its own latency entry.
Language support:	Verilog HDL, VHDL

get_response_queue_size()

Prototype:	`int get_response_queue_size()`
Arguments:	Verilog HDL: None VHDL: `response_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the response queue to determine number of response descriptors currently stored in the BFM. This is the number of responses the test program can immediately remove from the response queue for further processing.
Language support:	Verilog HDL, VHDL

get_response_read_id()

Prototype:	`[AV_TRANSACTIONID_W-1:0] get_response_read_id()`
Arguments:	Verilog HDL: None VHDL: `response_read_id`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonTransactionId_t`
Description:	Returns the read id of the transaction in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_read_response()

Prototype:	`bit[2**(AV_BURSTCOUNT_W-1) - 1:0] [AV_READRESPONSE_W-1:0] get_response_read_response(int index)`
Arguments:	Verilog HDL: `int index` VHDL: `response_read_response`, `int index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonReadResponse_t`
Description:	Returns the transaction read status in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_request()

Prototype:	`enum int[REQ_READ = 0, REQ_WRITE = 1, RED_IDLE = 2] get_response_request()`
Arguments:	Verilog HDL: None VHDL: `response_request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`Request_t`
Description:	Returns the transaction command type in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_wait_time()

Prototype:	`int get_response_wait_time(int index)`
Arguments:	Verilog HDL: `index` VHDL: `response_wait_time`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Returns the wait latency for transaction in the response descriptor that has been removed from the response queue. Each cycle in a burst has its own wait latency entry.
Language support:	Verilog HDL, VHDL

get_response_write_id()

Prototype:	`bit [AV_TRANSACTIONID_W-1:0] get_response_write_id()`
Arguments:	Verilog HDL: None VHDL: `response_write_id`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonTransactionId_t`
Description:	Returns the write id of the transaction in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_response_write_response()

Prototype:	`bit [2**(AV_BURSTCOUNT_W-1)-1:0] [AV_WRITERESPONSE_W-1:0] get_response_write_response(int index)`
Arguments:	Verilog HDL: `int index` VHDL: `response_write_response`, `int index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonWriteResponse_t`
Description:	Returns the transaction write status in the response descriptor that has been removed from the response queue.
Language support:	Verilog HDL, VHDL

get_write_response_queue_size()

Prototype:	`int get_write_response_queue_size()`
Arguments:	Verilog HDL: None VHDL: `write_response_queue_size`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the write response queue to determine number of response descriptors currently stored in the BFM. This is the number of responses the test program can immediately pop off the response queue for further processing.
Language support:	Verilog HDL, VHDL

get_version()

Prototype:	`string get_version()`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`String`
Description:	Returns BFM version as a string of three integers separated by periods. For example, version 14.1 sp1 is encoded as "14.1.1".
Language support:	Verilog HDL

init()

Prototype:	`init`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Initializes the Avalon-MM master interface.
Language support:	Verilog HDL, VHDL

pop_response()

Prototype:	`void pop_response()`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Removes the oldest response descriptor from the response queue, such that transaction information is available using the `get_response_`<rolename> commands.
Language support:	Verilog HDL, VHDL

push_command()

Prototype:	`void push_command()`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Inserts the fully populated transaction descriptor onto the pending transaction command queue.
Language support:	Verilog HDL, VHDL

set_clken()

Prototype:	`void set_clken(bit state)`
Arguments:	Verilog HDL: `bit state` VHDL: `bit state`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the assertion and deassertion of the clock enable signal.
Language support:	Verilog HDL, VHDL

set_command_address()

Prototype:	`void set_command_address(bit[AV_ADDRESS_W-1:0]addr)`
Arguments:	Verilog HDL: `addr` VHDL: `addr`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction address in the command descriptor.
Language support:	Verilog HDL, VHDL

set_command_arbiterlock()

Prototype:	`void set_command_arbiterlock (bit state)`
Arguments:	Verilog HDL: `bit state` VHDL: `bit state`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Controls the assertion or deassertion of the arbiterlock interface signal. The arbiterlock control is on the transaction boundaries and is not used when the Avalon-MM Master BFM is operating in burst mode.
Language support:	Verilog HDL, VHDL

set_command_byte_enable()

Prototype:	`void set_command_byte_enable(bit[AV_NUMSYMBOLS-1:0] byte_enable, int index)`
Arguments:	Verilog HDL: `byte_enable`, `index` VHDL: `byte_enable`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction byte enable field for the cycle of the burst command descriptor indicated by index. This field applies to both read and write operations.
Language support:	Verilog HDL, VHDL

set_command_burst_count()

Prototype:	`void set_command_burst_count(bit[AV_BURSTCOUNT_W-1:0] burst_count)`
Arguments:	Verilog HDL: burst_count VHDL: `burst_count`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the value driven on the Avalon interface `burstcount` pin. Generates a warning message if the specified `burst_count`is out of range. Not available if the `USE_BURSTCOUNT` parameter is false.
Language support:	Verilog HDL, VHDL

set_command_burst_size()

Prototype:	`void set_command_burst_size (bit[AV_BURSTCOUNT_W-1:0] burst_size)`
Arguments:	Verilog HDL: burst_size VHDL: `burst_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction burst count in the command descriptor to determine the number of words driven on the write burst command. The value might be different from the value specified in `set_command_burst_count` to generate illegal traffic for testing. Generates a warning if the value is different.
Language support:	Verilog HDL, VHDL

set_command_data()

Prototype:	`void set_command_data(bit[AV_DATA_W-1:0] data, int index)`
Arguments:	Verilog HDL: `data`, `index` VHDL: `data`, `index`,`bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction write data in the command descriptor. For burst transactions, the command descriptor holds an array of data, with each element individually set by this method.
Language support:	Verilog HDL, VHDL

set_command_debugaccess()

Prototype:	`void set_command_debugaccess`
Arguments:	Verilog HDL: bit state VHDL: `bit state`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Controls the assertion or deassertion of the debugaccess interface signal. The debugaccess control is on transaction boundaries.
Language support:	Verilog HDL, VHDL

set_command_idle()

Prototype:	`void set_command_idle(int idle, int index)`
Arguments:	Verilog HDL: int idle, int index VHDL: `int idle`, `int index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets idle cycles at the end of each transaction cycle. For read commands, idle cycles are inserted at the end of the command cycle. For burst write commands, idle cycles are inserted at the end of each write data cycle within the burst.
Language support:	Verilog HDL, VHDL

set_command_init_latency()

Prototype:	`void set_command_init_latency(int cycles)`
Arguments:	Verilog HDL: `cycles` VHDL: `cycles`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the number of cycles to postpone the start of a command.
Language support:	Verilog HDL, VHDL

set_command_lock()

Prototype:	`void set_command_lock (bit state)`
Arguments:	Verilog HDL: bit state VHDL: `bit state`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Controls the assertion or deassertion of the lock interface signal. Lock control is on the transaction boundaries. It is not used when the Avalon-MM Master BFM is operating in burst mode.
Language support:	Verilog HDL, VHDL

set_command_request()

Prototype:	`void set_command_request(Request_t request)`
Arguments:	Verilog HDL: Request_t request VHDL: `Request_t request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction type to read or write in the command descriptor. The enumeration type defines `REQ_READ` = 0 and `REQ_WRITE` = 1.
Language support:	Verilog HDL, VHDL

set_command_timeout()

Prototype:	`void set_command_timeout(int cycles)`
Arguments:	Verilog HDL: int cycles VHDL: `int cycles`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the number of elapsed cycles between waiting for a `waitrequest` and when time out is asserted. Disables time-out by setting the value to 0.
Language support:	Verilog HDL, VHDL

set_command_transaction_id()

Prototype:	`void set_command_transaction_id(bit[AV_TRANSACTIONID_W-1:0] id)`
Arguments:	`AvalonTransactionId_t id.` Verilog HDL: `tid` VHDL: `tid` , `bfm_id`,`req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction id number in the command descriptor.
Language support:	Verilog HDL, VHDL

set_command_write_response_request()

Prototype:	`void set_command_write_response_request` (logic request)
Arguments:	Verilog HDL: `request` VHDL: `request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the flag that enables or disables the write response requests in the command descriptor.
Language support:	Verilog HDL, VHDL

set_max_command_queue_size()

Prototype:	`void set_max_command_queue_size(int size)`
Arguments:	Verilog HDL: int size VHDL: `int size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the pending command queue size maximum threshold.
Language support:	Verilog HDL, VHDL

set_min_command_queue_size()

Prototype:	`void set_min_command_queue_size(int size)`
Arguments:	Verilog HDL: int size VHDL: `int size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the pending command queue size minimum threshold.
Language support:	Verilog HDL, VHDL

set_response_timeout()

Prototype:	`void set_response_timeout(int cycles)`
Arguments:	Verilog HDL: int cycles VHDL: `int cycles`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the number of cycles that may elapse before response time out. Disable time-out by setting the value to 0.
Language support:	Verilog HDL, VHDL

signal_all_transactions_complete

Prototype:	`signal_all_transactions_complete`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that all queued transactions have completed.
Language support:	Verilog HDL

signal_command_issued

Prototype:	`signal_command_issued`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the currently pending command has been driven to the interface.
Language support:	Verilog HDL

signal_fatal_error

Prototype:	`signal_fatal_error`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Notifies the testbench that a fatal error has occurred in this module.
Language support:	Verilog HDL

signal_max_command_queue_size

Prototype:	`signal_max_command_queue_size`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the maximum pending transaction queue size threshold has been exceeded.
Language support:	Verilog HDL

signal_min_command_queue_size

Prototype:	`signal_min_command_queue_size`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the pending transaction queue size is below the minimum threshold.
Language support:	Verilog HDL

signal_read_response_complete

Prototype:	`signal_read_response_complete`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the read response has been received and inserted into the response queue.
Language support:	Verilog HDL

signal_response_complete

Prototype:	`signal_response_complete`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Triggers when either `signal_read_response_complete` or `signal_write_response_complete` is triggered.
Language support:	Verilog HDL

signal_write_response_complete

Prototype:	`signal_write_response_complete`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the write response has been received and inserted into the response queue.
Language support:	Verilog HDL

Avalon-MM Slave BFM

The Avalon-MM Slave BFM implements the slave side of the Avalon-MM interface protocol. The Avalon-MM protocol is a standard memory-mapped protocol. It includes the following functionality:

Reads and writes typical of simple peripherals
Reads, writes, burst reads, and burst writes for typical memory devices

This BFM also includes a procedural interface to implement the following functions:

Monitoring of incoming commands
Passing incoming commands to the test program
Accepting response transactions from the test program
Driving responses

The following figure shows the top-level modules for a testbench. This testbench uses the Avalon-MM Slave BFM to verify an Avalon-MM Master device. In addition to the The example testbench includes the following components:

Avalon-MM Slave BFM
A test program
The DUT

The test program is written in HDL. It implements the following functions:

Programs the Avalon-MM master to issue Avalon-MM transactions
Programs the Avalon-MM Slave BFM to respond
Analyzes the results

Note: The BFMs allow illegal response transactions so that you can test the error-handling functionality of your DUT. Consequently, the BFMs cannot be relied upon to guarantee protocol compliance. The Avalon Monitor components verify protocol compliance.

Figure 7. Top-Level Module to Verify an Avalon-MM Master

Timing

The following timing diagram illustrates the sequence of events for an Avalon-MM Slave BFM. It shows the slave BFM responding to interleaved writes and reads when the readdatavalid signal is present.

Figure 8. Avalon-MM Slave Responding to Interleaved Write and Read Transactions

Table 8. Key to Annotations. The following table lists the annotations used in this figure.
Symbol	Description
T_{wt_1}	The response wait time, which is three cycles. The slave sets this value using the `set_interface_wait_time` command.
T_wr	`waitrequest` is sampled #1 after the falling edge of `clk`.
T_{wt_2}	The response wait time for the first read, which is 2 cycles. The slave sets this value using the `set_interface_wait_time` command.
S_{cr_1}–S_{cr_2}	Signals when read commands were received. The event name is `signal_command_received`.
T_{rl_1},T_{rl_2}	The response latency for the reads, which is 3 cycles. The slave sets this time using the `set_response_latency` command.
T_{wrl_1}	The write response latency for the first write, which is 3 cycles. This is the time between when the write command is accepted, and the write response is provided by the slave. T
S_{rc_1},S_{rc_3}	Signals write responses. The event name is `signal_response_issued.`
S_{rc_2},S_{rc_4}	Signals read responses. The event name is `signal_response_issued.`
T_{ID_1}–T_{ID_4}	Reference number to identify each read or write transaction.
ID_1, ID_3	Reference number to identify write transactions.
ID_2, ID_4	Reference number to identify read transactions.

Figure 9. Avalon-MM Slave Receiving Write and Read Commands with No readdatavalid Signal. The following timing diagram illustrates the sequence of events for an Avalon-MM Slave BFM. The slave BFM receives a write followed by a read when the readdatavalid signal is not present.

Table 9. Key to Annotations. The following table lists the annotations used in this figure.
Symbol	Description
T_i	The initial command latency which is two cycles for transactions 1 and 2.
T_{wt_1}	The response wait time which is 3 cycles. The master gets this value using the `get_response_wait_time` command.
T_{wt_2}	The response wait time for the first read, which is 2 cycles. The slave sets this value using the `set_interface_wait_time` command.
T_wr	`waitrequest` is sampled #1 after the falling edge of `clk`.
T_{rl_1}	The response latency for the first read, which is 0 cycles. The master gets this time using the `get_response_latency` command.
S_{cr_1,}S_{cr_2}	Signals write and read commands. The event name is `signal_command_issued`.
S_{rc_1}	Signals the first read response. The event name is `signal_response_complete.`
S_atc	Signals the end of the test. The event name is `signal_all_transactions_complete`

Block Diagram

The following figure provides a block diagram of the Avalon-MM Slave BFM. The BFM includes the following major blocks:

Avalon-MM Slave API—Provides methods to get commands and create responses to commands from the Avalon-MM master (DUT).
Command Descriptor—Accumulates the fields of a command sent by the Avalon-MM master. Sends completed commands to the Avalon-MM Slave BFM when requested.
Avalon-MM Interface Monitor—Monitors activity coming from the Avalon-MM Master (DUT). Stores commands in the Client Command Queue.
Response Generator and Data Cache— In memory_mode the Slave BFM models a single port RAM. A write operation stores the data in an associative array and generates no response. A read operation fetches data from the array and drives it on the response side of the Avalon interface. This mode simplifies loopback testing.
Avalon-MM Slave Interface Driver—Drives responses to the system interconnect fabric. For burst transfers, there is a separate transfer for each word of the burst. The client testbench can instruct the Slave BFM to assert waitrequest for each word of the burst to test the functionality of the Avalon-MM master.
Public Events—Provides status response that arrives together with the data. The public event signals indicate the status of the Master’s request such as successful completion, timeout, or error.
Figure 10. Avalon-MM Slave BFM Block Diagram

Parameters

The Avalon-MM Slave BFM supports the full range of signals defined for the Avalon-MM slave interface. The following table describes parameters you can customize the Avalon-MM slave interface.

Table 10. Parameters for the Avalon-MM Slave BFM
Parameter	Default Value	Legal Values	Description
Port Widths
Address width	32	N/A	Address width in bits.
Symbol width	8	N/A	Data symbol width in bits. Set `AV_SYMBOL_W` to 8 for byte-oriented interfaces.
Read Response width	8	N/A	Read status response width in bits.
Write Response width	8	N/A	Write status response width in bits.
Parameters
Number of symbols	4	N/A	Number of symbols per word.
Burstcount width	3	N/A	The width of the burst count in bits.
Port Enables
Use the read signal	On	On/Off	When On, the interface includes a `read` pin.
Use the write signal	On	On/Off	When On, the interface includes a `write` pin.
Use the address signal	On	On/Off	When On, the interface includes `address` pins.
Use the byte enable signal	On	On/Off	When On, the interface includes `byte_enable` pins.
Use the burstcount signal	On	On/Off	When On, the interface includes `burstcount` pins.
Use the readdata signal	On	On/Off	When On, the interface includes a `readdata` pin.
Use the readdatavalid signal	On	On/Off	When On, the interface includes a `readdatavalid` pin.
Use the writedata signal	On	On/Off	When On, the interface includes a `writedata` pin.
Use the begintransfer signal	Off	On/Off	When On, the interface includes `writedata` pins.
Use the beginbursttransfer signal	Off	On/Off	When On, the interface includes a `beginbursttransfer` pin.
Use the arbiterlock signal	Off	On/Off	When On, the interface includes an `arbiterlock` pin.
Use the lock signal	Off	On/Off	When On, the interface includes a `lock` pin.
Use the debugaccess signal	Off	On/Off	When On, the interface includes a `debugaccess` pin.
Use the waitrequest signal	On	On/Off	When On, the interface includes a `waitrequest` pin.
Use the transactionid signal	Off	On/Off	When On, the interface includes a `transactionid` pin.
Use the write response signals	Off	On/Off	When On, the interface includes a `writeresponse` pin.
Use the read response signals	Off	On/Off	When On, the interface includes a `readresponse` pin.
Use the clken signals	Off	On/Off	When On, the interface includes a `clken` pin.
Port Polarity
Assert reset high	On	On/Off	When On, `reset` is asserted high.
Assert waitrequest high	On	On/Off	When On, `waitrequest` is asserted high.
Assert read high	On	On/Off	When On, `read` is asserted high.
Assert write high	On	On/Off	When On, `write` is asserted high.
Assert byteenable high	On	On/Off	When On, `byteenable` is asserted high.
Assert readdatavalid high	On	On/Off	When On, `readdatavalid` is asserted high.
Assert arbiterlock high	On	On/Off	When On, `arbiterlock` is asserted high.
Assert lock high	On	On/Off	When On, `lock` is asserted high.
Burst Attributes
Linewrap burst	On	On/Off	When On, the address for bursts wraps instead of an incrementing. With a wrapping burst, when the address reaches a burst boundary, it wraps back to the previous burst boundary. Consequently, only the low order bits need to be used for addressing.
Burst on burst boundaries only	On	On/Off	When On, memory bursts are aligned to the address size.
Miscellaneous
Maximum pending reads	1	N/A	The maximum number of pending reads which can be queued up by the slave.
VHDL BFM ID	0	0–1023	For VHDL BFMs only. Use this option to assign a unique number to each BFM in the testbench design.
Timing
Fixed read latency (cycles)	0	N/A	Sets the read latency for fixed-latency slaves. Not used on interfaces that include the `readdatavalid` signal.
Fixed read wait time (cycles)	1	N/A	For slave interfaces that do not use the `waitrequest` signal. The read wait time indicates the number of cycles before the slave responds to a read. The timing is as if the slave asserted `waitrequest` for this number of cycles.
Fixed write wait time (cycles)	0	N/A	For slave interfaces that do not use the `waitrequest` signal. The write wait time indicates the number of cycles before the slave accepts a write.
Registered waitrequest	On	On/Off	Specifies whether to turn on the register stage.
Registered Incoming Signals	On	On/Off	Specifies whether to register incoming signals.
Interface Address Type
Set slave interface address type to symbols or words	WORDS	WORDS/ SYMBOLS	Sets slave interface address type to symbols or words.

Avalon-MM Slave BFM API

event_error_exceed_max_pending_reads()

Prototype:	`event_error_exceed_max_pending_reads` `()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`, `req_if`
Returns:	`void`
Description:	Notifies the testbench that the BFM has more than the maximum pending reads in the pipelined read commands queue waiting to be processed.
Language support:	VHDL

event_command_received()

Prototype:	`event_command_received` `()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that a command was received.
Language support:	VHDL

event_response_issued()

Prototype:	`event_response_issued` `()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that a response was driven to the interface.
Language support:	VHDL

event_max_response_queue_size()

Prototype:	`event_max_response_queue_size` `()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that the response queue size has reached the threshold limit.
Language support:	VHDL

event_min_response_queue_size()

Prototype:	`event_min_response_queue_size` `()`
Arguments:	Verilog HDL: N.A. VHDL: `bfm_id`
Returns:	`void`
Description:	Notifies the testbench that the response queue size is below the minimum limit.
Language support:	VHDL

get_clken()

Prototype:	`logic get_clken()`
Arguments:	Verilog HDL: None VHDL: `clken`, `bfm_id`, `req_if(bfm_id)`
Returns:	`logic`
Description:	Returns the clock enable signal status.
Language support:	Verilog HDL, VHDL

get_command_address()

Prototype:	`bit [AV_ADDRESS_W-1:0] get_command_address()`
Arguments:	Verilog HDL: None VHDL: `command_address`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit [AV_ADDRESS_W-1:0]`
Description:	Queries the received command descriptor for the transaction address.
Language support:	Verilog HDL, VHDL

get_command_arbiterlock()

Prototype:	`bit get_command_arbiterlock()`
Arguments:	Verilog HDL: None VHDL: `command_arbiterlock`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Queries the received command descriptor for the transaction arbiterlock.
Language support:	Verilog HDL, VHDL

get_command_burst_count()

Prototype:	`[AV_BURSTCOUNT_W-1:0] get_command_burst_count()`
Arguments:	Verilog HDL: None VHDL: `command_burst_count`, `bfm_id`, `req_if(bfm_id)`
Returns:	`[AV_BURSTCOUNT_W-1:0]`
Description:	Queries the received command descriptor for the transaction burst count.
Language support:	Verilog HDL, VHDL

get_command_burst_cycle()

Prototype:	`int get_command_burst_cycle()`
Arguments:	Verilog HDL: None VHDL: `command_burst_cycle`, `bfm_id`, `req_if(bfm_id)`
Returns:	`Int`
Description:	The slave BFM receives and processes write burst commands as a sequence of discrete commands. The number of commands corresponds to the burst count. A separate command descriptor is constructed for each write burst cycle. Each command corresponds to a partially completed burst. This method returns a burst cycle field telling the testbench which burst cycle was active when this descriptor was constructed. This facility enables the testbench to query partially completed write burst operations.The testbench can query the write data word on each burst cycle as it arrives. Consequently, the testbench can begin to process it immediately rather than waiting until the entire burst has been received. This facility means you can implement pipelined write burst processing in the testbench.
Language support:	Verilog HDL, VHDL

get_command_byte_enable()

Prototype:	`bit [AV_NUMSYMBOLS-1:0] get_command_byte_enable (int index)`
Arguments:	Verilog HDL: `index` VHDL: `command_byte_enable`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit [AV_NUMSYMBOLS-1:0]`
Description:	Queries the received command descriptor for the transaction byte enable. For burst commands with burst count greater than 1, the index selects the data cycle.
Language support:	Verilog HDL, VHDL

get_command_data()

Prototype:	`bit [AV_DATA_W-1:0] get_command_data(int index)`
Arguments:	Verilog HDL: `index` VHDL: `command_data`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit [AV_DATA_W-1:0]`
Description:	Queries the received command descriptor for the transaction write data. For burst commands with burst count greater than 1, the index selects the write data cycle.
Language support:	Verilog HDL, VHDL

get_command_debugaccess()

Prototype:	`bit get_command_debugaccess()`
Arguments:	Verilog HDL: None VHDL:`command_debugaccess`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Queries the received command descriptor for the transaction debug access.
Language support:	Verilog HDL, VHDL

get_command_queue_size()

Prototype:	`int get_command_queue_size()`
Arguments:	Verilog HDL: None VHDL: `command_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the command queue to determine number of pending commands.
Language support:	Verilog HDL, VHDL

get_command_lock()

Prototype:	`bit get_command_lock()`
Arguments:	Verilog HDL: None VHDL: `command_lock`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Queries the received command descriptor for the transaction lock.
Language support:	Verilog HDL, VHDL

get_command_request()

Prototype:	`Request_t get_command_request()`
Arguments:	Verilog HDL: None VHDL: `command_request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`Request_t` (enumerated type)
Description:	Gets the received command descriptor to determine command request type. A command type may be `REQ_READ` or `REQ_WRITE`. These type values are defined in the enumerated type called `Request_t`, which is imported with the package named `altera_avalon_mm_pkg`.
Language support:	Verilog HDL, VHDL

get_command_transaction_id()

Prototype:	`AvalonTransactionId_t get_command_transaction_id()`
Arguments:	Verilog HDL: None VHDL: `command_transaction`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonTransactionId_t`
Description:	Queries the received command descriptor for the transaction ID.
Language support:	Verilog HDL, VHDL

get_command_write_response_request()

Prototype:	`AvalonTransactionId_t get_command_write_response_request()`
Arguments:	Verilog HDL: None VHDL: `command_write_response_request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`AvalonTransactionId_t`
Description:	Queries the received command descriptor for the `write_response_request` field value. A value of 1 indicates that the master has requested for a write response.
Language support:	Verilog HDL, VHDL

get_pending_read_latency_cycle()

Prototype:	`int get_pending_read_latency_cycle()`
Arguments:	Verilog HDL: None VHDL: `pending_read_latency_cycle`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the read command queue to determine the cycles needed for the Slave BFM to complete the current read response. This method notifies the master when the Slave BFM is ready to receive a command.
Language support:	Verilog HDL, VHDL

get_pending_write_latency_cycle()

Prototype:	`int get__cycle()`
Arguments:	Verilog HDL: None VHDL: `pending_write_latency`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the write command queue to determine the cycles needed for the Slave BFM to complete the current write response.
Language support:	Verilog HDL, VHDL

get_response_queue_size()

Prototype:	`int get_response_queue_size()`
Arguments:	Verilog HDL: None VHDL: `response_queue_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`int`
Description:	Queries the response queue to determine number of response descriptors pending.
Language support:	Verilog HDL, VHDL

vget_slave_bfm_status

Prototype:	`bit get_slave_bfm_status`
Arguments:	Verilog HDL: None VHDL: `slave_bfm_status`, `bfm_id`, `req_if(bfm_id)`
Returns:	`bit`
Description:	Queries the Slave BFM component to determine when the read transaction in the Slave BFM has reached the maximum read transactions. A return value of 1 means that the Slave BFM can no longer accept a new read command.
Language support:	Verilog HDL, VHDL

get_version()

Prototype:	`string get_version()`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`String`
Description:	Returns BFM version as a string of three integers separated by periods. For example, version 10.1 sp1 is encoded as "10.1.1".
Language support:	Verilog HDL

init()

Prototype:	`init()`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Initializes the Avalon-MM slave interface.
Language support:	Verilog HDL, VHDL

pop_command()

Prototype:	`void pop_command()`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Removes the command descriptor from the queue so that the testbench can query it using the `get_command` methods.
Language support:	Verilog HDL, VHDL

push_response()

Prototype:	`void push_response()`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Inserts the fully populated response transaction descriptor onto the response queue. The BFM removes response descriptors from the queue as soon as they are available. The BFM reads them and drives the Avalon-MM interface response plane.
Language support:	Verilog HDL, VHDL

set_command_transaction_mode()

Prototype:	`void set_command_transaction_mode (int mode)`;
Arguments:	Verilog HDL: `mode` VHDL: `mode`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	By default, write burst commands are consolidated into a single command transaction. The single command transaction contains the write data for all burst cycles in that command. This mode is set when the mode argument equals 0. When the mode argument is set to 1, the write burst commands yield one command transaction per burst cycle.
Language support:	Verilog HDL, VHDL

set_interface_wait_time()

Prototype:	`void set_interface_wait_time(int wait_cycles, int index)`
Arguments:	Verilog HDL: `wait_cycles`, `index` VHDL: `wait_cycles`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Specifies zero or more wait states to assert in each Avalon burst cycle by driving `waitrequest` active. With write burst commands, each write data cycle must wait the number of cycles corresponding to the cycle index. With read burst commands, there is only one command cycle corresponding to index 0 which can be forced to wait.
Language support:	Verilog HDL, VHDL

vset_max_response_queue_size()

Prototype:	`void set_max_response_queue_size(int size)`
Arguments:	Verilog HDL: `int size` VHDL: `int size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the maximum pending response queue size threshold.
Language support:	Verilog HDL, VHDL

set_min_response_queue_size()

Prototype:	`void set_min_response_queue_size(int size)`
Arguments:	Verilog HDL: `int size` VHDL: `int size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the minimum pending response queue size threshold.
Language support:	Verilog HDL, VHDL

set_read_response_id()

Prototype:	`void set_read_respose_id(AvalonTransactionId_t id)`
Arguments:	Verilog HDL: `AvalonTransactionId_t id` VHDL: `AvalonTransactionId_t id`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction ID on the `avs_readid` pin.
Language support:	Verilog HDL, VHDL

set_read_response_status()

Prototype:	`void set_read_respose_status(AvalonReadResponse_t status, int index)`
Arguments:	Verilog HDL: `AvalonReadResponse_t status`, `int index` VHDL: `AvalonReadResponse_t status`, `int index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the read response status code.
Language support:	Verilog HDL, VHDL

set_response_burst_size()

Prototype:	`void set_response_burst_size(bit [AV_BURSTCOUNT_W-1:0] burst_size)`.
Arguments:	Verilog HDL: `burst_size` VHDL: `burst_size`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction burst count in the response descriptor.
Language support:	Verilog HDL, VHDL

set_response_data()

Prototype:	`void set_response_data(bit [AV_DATA_W-1:0] data, int index)`.
Arguments:	Verilog HDL: `data`, `index` VHDL: `data`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction read data in the response descriptor. For burst transactions, the command descriptor holds an array of data, with each element individually set by this method.
Language support:	Verilog HDL, VHDL

set_response_latency()

Prototype:	`void set_response_latency(bit [31:0]latency, int index)`
Arguments:	Verilog HDL: `latency`, `index` VHDL: `latency`, `index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the response latency for read commands. The response is driven `latency` number of cycles after receiving the read command. Designs that set `USE_READDATAVALID` to 1, cannot set the response latency to 0. For read burst commands the following algorithm determines the read latency: If there are no pending read responses for prior read commands, the response latency is counted from the cycle that the read command is accepted. The read is accepted when the read command is asserted and `waitrequest` is deasserted. If there are pending responses for prior read commands, the response latency is counted from the cycle in which the read command is presented. The read command is presented when the read command is asserted even if `waitrequest` is asserted.
Language support:	Verilog HDL, VHDL

set_response_request()

Prototype:	`void set_response_request(Request_t request)`
Arguments:	Verilog HDL: `Request_t request` VHDL: `Request_t request`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction type to read or write in the response descriptor. The enumeration type defines `REQ_READ` = `0` and `REQ_WRITE` = `1`.
Language support:	Verilog HDL, VHDL

set_response_timeout()

Prototype:	`void set_response_timeout(int cycles)`
Arguments:	Verilog HDL: None VHDL: `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the number of cycles that may elapse before timing out.
Language support:	Verilog HDL, VHDL

set_write_response_id()

Prototype:	`void set_write_respose_id(AvalonTransactionId_t id)`
Arguments:	Verilog HDL: `AvalonTransactionId_t id` VHDL: `AvalonTransactionId_t id`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the transaction ID on the `avs_writeid` pin.
Language support:	Verilog HDL, VHDL

set_write_response_status()

Prototype:	`void set_write_respose_status(AvalonWriteResponse_t status, int index)`
Arguments:	Verilog HDL: `AvalonWriteResponse_t status`, `int index` VHDL: `AvalonWriteResponse_t status`, `int index`, `bfm_id`, `req_if(bfm_id)`
Returns:	`void`
Description:	Sets the write response status code.
Language support:	Verilog HDL, VHDL

signal_command_received()

Prototype:	`signal_command_received`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Notifies the testbench that a command has been detected on an Avalon-MM port. The testbench can respond with a `set_command_wait_time` call on receiving this event to dynamically back pressure the driving Avalon-MM master. Alternatively, the previously set `wait_time` might be used continuously for a set of transactions.
Language support:	Verilog HDL

signal_error_exceed_max_pending_reads

Prototype:	`signal_error_exceed_max_pending_reads`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Notifies the testbench of the error condition, in which the slave has more than `max_pending_reads` pipelined read commands queued and waiting to be processed.
Language support:	Verilog HDL

signal_max_response_queue_size

Prototype:	`signal_max_response_queue_size`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the maximum pending transaction queue size threshold has been exceeded.
Language support:	Verilog HDL

signal_min_command_queue_size

Prototype:	`signal_min_response_queue_size`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Signals that the pending transaction queue size is below the minimum threshold.
Language support:	Verilog HDL

signal_fatal_error

Prototype:	`signal_fatal_error`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Notifies the testbench that a fatal error has occurred in this module.
Language support:	Verilog HDL

signal_response_issued

Prototype:	`signal_response_issued`
Arguments:	Verilog HDL: None VHDL: N.A.
Returns:	`void`
Description:	Notifies the testbench that a response has been driven out on the Avalon bus.
Language support:	Verilog HDL

Avalon-MM Monitor

The Avalon-MM Monitor verifies Avalon-MM interfaces using SystemVerilog assertions. In addition, it provides test coverage reports. The coverage reports provide the information necessary to determine when your test vectors provide sufficient test coverage of the DUT.

The Avalon-MM Monitor is implemented in SystemVerilog and uses the SystemVerilog Assertion (SVA) language. The SVA language is supported by the Synopsys VCS, and Mentor Graphics Questa simulators. If you are using ModelSim, the monitor component still compiles and simulates. However, the assertion checking is disabled.

The following figure shows a testbench that uses an Avalon-MM Monitor to test components with Avalon-MM interfaces. The monitor’s Avalon-MM Master interface is connected to a component’s Avalon-MM slave interface. An Avalon-MM Slave interface is connected to a component’s Avalon-MM master interface. The test program communicates with the monitor. The test program can use the monitor’s assertion checking and coverage groups to ensure that all legal parameter values for the DUT’s Avalon-MM interface are tested. The Avalon-MM Monitor also includes a transaction collector feature to collect and monitor transaction status.

Figure 11. Testbench Using an Avalon-MM Monitor with Avalon-MM Interfaces

Parameters

The Avalon-MM Monitor supports the full range of signals defined for the Avalon-MM master and slave interfaces. You can customize the Avalon-MM master and slave interfaces using the parameters described in the following table.

Table 11. Parameters for the Avalon-MM Monitor
Parameter	Default Value	Legal Values	Description
Port Widths
Address width	32	N/A	Address width in bits.
Symbol width	8	N/A	Data symbol width in bits. The symbol width should be 8 for byte-oriented interfaces.
Number of symbols	4	N/A	Numbers of symbols per word.
Burstcount width	3	N/A	The width of the burst count in bits.
Readresponse width	8	N/A	Read response signal width in bits.
Writeresponse width	8	N/A	Write response signal width in bits.
Port Enables
Use the read signal	On	On/Off	When On, the interface includes a `read` pin.
Use the write signal	On	On/Off	When On, the interface includes a `write` pin.
Use the address signal	On	On/Off	When On, the interface includes `address` pins.
Use the byte enable signal	On	On/Off	When On, the interface includes `byte_enable` pins.
Use the burstcount signal	On	On/Off	When On, the interface includes `burstcount` pins.
Use the readdata signal	On	On/Off	When On, the interface includes a `readdata` pin.
Use the readdatavalid signal	On	On/Off	When On, the interface includes a `readdatavalid` pin.
Use the writedata signal	On	On/Off	When On, the interface includes a `writedata` pin.
Use the begintransfer signal	Off	On/Off	When On, the interface includes `writedata` pins.
Use the beginbursttransfer signal	Off	On/Off	When On, the interface includes a `beginbursttransfer` pins.
Use the waitrequest signal	On	On/Off	When On, the interface includes a `waitrequest` pin.
Use the arbiterlock signal	Off	On/Off	When On, the interface includes an `arbiterlock`pin.
Use the lock signal	Off	On/Off	When On, the interface includes a `lock` pin.
Use the debugaccess signal	Off	On/Off