Altera Avalon Verification IP Suite - Manual (Page 92)

Chapter 1: Avalon-ST Source BFM 1–3
Functional Description
May 2011 Altera Corporation Avalon Verification IP Suite User Guide
Block Diagram
Figure 1–3 shows a block diagram of the Avalon-ST Source BFM. This figure
illustrates, the BFM includes the following six major blocks:
■ Avalon-ST Source API—Provides methods to create Avalon-ST transactions and
query the state of all queues.
■ Transaction Descriptor—Accumulates the fields of an Avalon-ST command and
inserts completed commands onto the pending command queue.
■ Avalon-ST Physical Driver—Issues transfers and holds each transfer until ready is
asserted.
■ Physical Bus Monitor—Monitors the physical layer and reports on the status of the
ready signal to the Physical Bus Driver and the Public Events module.
■ Public Events—Signals the events described in the API.
■ Response Descriptor—Collects information about completed transactions.
Figure 1–3. Block Diagram of the Avalon-ST Source BFM
Transaction Descriptor
Public
Events
Avalon-ST Source BFM API
(Transaction Level Commands)
Avalon-ST Interface
Physical Layer
Response Descriptor
Transaction
Queue
Pending
Response
Queue
Physical
Bus Driver
Physical
Bus Monior
valid
data
channel
startofpacket
endofpacket
error
empty ready
push_transaction() pop_transaction()
Backpressure (ready)
Backpressure
latency
Signals
Events