Write burst transaction creation and execution, The code excerpt in, Example 11-3 – Altera Mentor Verification IP Altera Edition AMBA AXI3/4TM User Manual

Page 630

Mentor VIP AE AXI3/4 User Guide, V10.2b

610

VHDL Tutorials
Verifying a Slave DUT

September 2013

The read data is obtained using the

get_data_words()

procedure to get the data_words[0]

transaction field value. The result of the read data is compared with the expected data—and a
report message displays the transcript.

Example 11-3. Read Transaction Creation and Execution

--Read data from address 1.
create_read_transaction(1, tr_id, index, axi_tr_if_0(index));
set_id(1, tr_id, index, axi_tr_if_0(index));
set_size(AXI_BYTES_1, tr_id, index, axi_tr_if_0(index));
execute_transaction(tr_id, index, axi_tr_if_0(index));

get_data_words(data_words, tr_id, index, axi_tr_if_0(index));
if(data_words(31 downto 0) = x"00000100") then

report "master_test_program: Read correct data (1) at address (1)";

else

hwrite(lp, data_words(31 downto 0));
report "master_test_program: Error: Expected data (1) at address 1,
but got " & lp.all;

end if;

In the complete Master Test Program, three subsequent read transactions are created and
executed in a similar manner to that shown in

code listing for details.

Write Burst Transaction Creation and Execution

The code excerpt in

Example 11-4

calls the

create_write_transaction()

procedure to create a

write burst transaction by providing the start address and burst length arguments. The actual
length of the burst on the protocol signals is 7+1=8.

Note

The burst length argument passed to the

create_write_transaction()

procedure is 1 less

than the number of transfers (beats) in the burst. This aligns the burst length argument
value with the value placed on the AWLEN protocol signals.

The

set_data_words()

procedure is then called eight times to set the data_words field of the

write transaction for each beat of the data burst. For this write transaction, all data byte lanes
contain valid data on each beat of the data burst, therefore a ‘for loop’ calls the

set_write_strobes()

procedure to set the write_strobes fields of the transaction to 15 for each

beat of the burst.

The call to

set_write_data_mode()

procedure configures the write burst transaction to allow the

write address phase and write data burst to start simultaneously
(AXI_DATA_WITH_ADDRESS) when executed. The write transaction is then executed onto
the protocol signals.