Altera Mentor Verification IP Altera Edition AMBA AXI4-Lite - Manual (Page 346)

Mentor Verification IP AE AXI4-Lite User Guide, V10.3 346
VHDL Tutorials
Verifying a Master DUT
April 2014
The maximum number of outstanding read transactions is configured before the processing of
read transactions begins an ACLK period after the ARESETn signal is inactive, as shown in
Example 11-13 .
Each slave transaction has a unique transaction_id number associated with it that is
automatically incremented for each new slave transaction created. In a loop, the
create_slave_transaction() procedure call returns the transaction_id for the slave BFM,
indexed by the index argument. A read_trans variable is previously defined to hold the
transaction_id.
A call to the get_read_addr_phase() procedure blocks the code until a read address phase has
completed. The call to the push_transaction_id() procedure pushes read_trans into the
AXI4_QUEUE_ID_1 queue.
The loop completes and restarts by creating a new slave transaction and blocks for another write
address phase to occur.
Example 11-13. process_read
-- process_read : read address phase through path 3
-- This process keep receiving read address phase and push
-- the transaction into queue through push_transaction_id API.
process
variable read_trans: integer;
begin
wait_on(AXI4_RESET_0_TO_1, index, AXI4_PATH_3,
axi4_tr_if_3(index));
wait_on(AXI4_CLOCK_POSEDGE, index, AXI4_PATH_3,
axi4_tr_if_3(index));
loop
create_slave_transaction(read_trans, index, AXI4_PATH_3,
axi4_tr_if_3(index));
get_read_addr_phase(read_trans, index, AXI4_PATH_3,
axi4_tr_if_3(index));
get_config(AXI4_CONFIG_NUM_OUTSTANDING_RD_PHASE,
tmp_config_num_outstanding_rd_phase, index,
AXI4_PATH_3, axi4_tr_if_3(index));
push_transaction_id(read_trans, AXI4_QUEUE_ID_1, index,
AXI4_PATH_3, axi4_tr_if_3(index));
end loop;
wait;
end process;
handle_read
The handle_read process gets read data from the Internal Memory as a phase (beat). It uses
unique path and queue identifiers to work concurrently with other processes.
In a loop, the pop_transaction_id() procedure call returns the transaction_id from the queue for
the slave BFM, indexed by the index argument, as shown in Example 11-14 . A read_trans