Understanding the test steps, Understanding the test steps -2 – Altera Avalon Verification IP Suite User Manual

Page 205

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• The test program controls the BFMs using the BFM API to drive and monitor transactions.

Figure 16-1: Top-Level Testbench for Avalon-ST DUT Component

Qsys Generated Testbench

Top-Level File

Test

Program

Avalon-ST

Single-Clock

FIFO Buffer

(DUT)

Avalon Clock

Source BFM

Avalon-ST

Source BFM

Avalon-ST

Sink BFM

Avalon Reset

Source BFM

Understanding the Test Steps

The test flow includes the following steps:

1. The test program initializes the BFMs.
2. The test program runs the following three parallel processes:

a. Process 1 creates and sends four test transactions to the source BFM. The transactions consist of the

following six Avalon-ST signals:

data

,

channel

,

error

,

empty

,

startofpacket

,

endofpacket

, and

idle

. The Avalon-ST Source BFM drives the transactions to the Avalon-ST Single-Clock FIFO buffer.

In addition, the Avalon-ST Source BFM keeps a local copy of the transactions for future reference.
The Avalon-ST Source BFM prints the transaction values in the ModelSim transcript console.

b. Process 2 controls the Avalon-ST Sink BFM. When the Avalon-ST Sink BFM receives a transaction,

it completes the following steps:

• It reads the transaction values.
• It prints the transaction values on the ModelSim transcript console.
• It compares the values it receives to the values from the Avalon-ST Source BFM.
• It reports any mismatch in values as failures.
• During this process, the Avalon-ST Sink BFM backpressures the Avalon-ST Single-Clock FIFO

buffer.

c. Process 3 measures the response latency when the Avalon-ST Single-Clock FIFO buffer backpressures

the Avalon-ST Source BFM. The Avalon-ST Source BFM prints the transaction values on the ModelSim
transcript console.

Avalon-ST Verilog HDL Testbench

Altera Corporation

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Understanding the Test Steps

16-2

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