Altera Mentor Verification IP Altera Edition AMBA AXI3/4TM - Manual (Page 643)

VHDL Tutorials
Verifying a Master DUT
Mentor VIP AE AXI3/4 User Guide, V10.2b 623
September 2013
AXI3 Basic Slave API Definition
The Slave Test Program Basic API contains:
•
Procedures that read and write a byte of data to internal memory do_byte_read() and
do_byte_write() , respectively.
•
Procedures to configure the AXI3 protocol channel handshake delays
set_read_address_ready_delay() , set_write_address_ready_delay() ,
set_write_data_ready_delay() , set_read_data_valid_delay() and
set_wr_resp_valid_delay() .
•
Procedures to process read and write transactions, process_read and process write ,
respectively. If you need to create other responses, such as EXOKAY, DECERR, or
SLVERR, then you must edit these procedures to provide the required response.
•
A slave_mode transaction field to control the behavior of reading and writing to the
internal memory.
•
Configuration variables m_max_outstanding_read_trans and
m_max_outstanding_write_trans back-pressure a master from transmitting additional
read and write transactions when the configured value has been reached.
The internal memory for the slave is defined as an array of 8-bits, so that each byte of data is
stored as an address/data pair.
Example 11-16. internal memory
type memory_t is array (0 to 2**16-1) of std_logic_vector(7 downto 0);
shared variable mem : memory_t;
The do_byte_read() procedure, when called, reads a data byte from the internal memory mem,
given an address location addr, as demonstrated in Example 11-17 .
You can edit this procedure to modify the way the read data is extracted from the internal
memory.
Example 11-17. do_byte_read()
-- Procedure : do_byte_read
-- Procedure to provide read data byte from memory at particular input
-- address
procedure do_byte_read
(
addr : in std_logic_vector(AXI_MAX_BIT_SIZE-1 downto 0);
data : out std_logic_vector(7 downto 0)
) is
begin
data := mem(to_integer(addr));
end do_byte_read;