Altera Mentor Verification IP Altera Edition AMBA AXI3/4TM - Manual (Page 666)

Mentor VIP AE AXI3/4 User Guide, V10.2b 646
VHDL Tutorials
Verifying a Master DUT
September 2013
If the slave_mode configuration is set to the default of AXI4_TRANSACTION_SLAVE then the
burst_length loop continues until the read data has been set for the whole burst. Otherwise the
individual read data phase is executed over the protocol signals by calling the
execute_read_data_phase() .
After the burst_length loop is complete, execute_read_data_burst() is called for the default
configuration of slave_mode and the read burst is executed over the protocol signals.
The loop completes and restarts by waiting for another transaction_id to be placed into the
queue.
Example 11-37. handle_read
-- handle_read : read data and response through path 4
-- This process reads data from memory and send read data/response either
-- at burst or phase level depending upon slave working mode.
process
variable read_trans: integer;
variable burst_length : integer;
variable byte_length : integer;
variable addr : std_logic_vector(AXI4_MAX_BIT_SIZE-1 downto 0);
variable data : std_logic_vector(7 downto 0);
begin
loop
pop_transaction_id(read_trans, AXI4_QUEUE_ID_1, index, AXI4_PATH_4,
axi4_tr_if_4(index));
set_read_data_valid_delay(read_trans, AXI4_PATH_4,
axi4_tr_if_4(index));
get_burst_length(burst_length, read_trans, index, AXI4_PATH_4,
axi4_tr_if_4(index));
for i in 0 to burst_length loop
get_read_addr(read_trans, i, 0, byte_length, addr, index,
AXI4_PATH_4, axi4_tr_if_4(index));
do_byte_read(addr, data);
set_read_data(read_trans, i, 0, byte_length, addr, data, index,
AXI4_PATH_4, axi4_tr_if_4(index));
if byte_length > 1 then
for j in 1 to byte_length-1 loop
get_read_addr(read_trans, i, j, byte_length, addr, index,
AXI4_PATH_4, axi4_tr_if_4(index));
do_byte_read(addr, data);
set_read_data(read_trans, i, j, byte_length, addr, data,
index, AXI4_PATH_4, axi4_tr_if_4(index));
end loop;
end if;
if slave_mode = AXI4_PHASE_SLAVE then
execute_read_data_phase(read_trans, i, index, AXI4_PATH_4,
axi4_tr_if_4(index));
end if;
end loop;
if slave_mode = AXI4_TRANSACTION_SLAVE then
execute_read_data_burst(read_trans, index, AXI4_PATH_4,
axi4_tr_if_4(index));
end if;