Altera Avalon Verification IP Suite - Manual (Page 28)

Chapter 1: Avalon-MM Master BFM 1–5
Functional Description
May 2011 Altera Corporation Avalon Verification IP Suite User Guide
Block Diagram
Figure 1–4 shows 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 calls and 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.
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.
Table 1–2. Key to Annotations in Figure 1–3 (Part 2 of 2)
Symbol Description