URL
https://opencores.org/ocsvn/light8080/light8080/trunk
Subversion Repositories light8080
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/light8080/trunk/vhdl
- from Rev 41 to Rev 42
- ↔ Reverse comparison
Rev 41 → Rev 42
/test/light8080_tb1.vhdl
1,521 → 1,549
-------------------------------------------------------------------------------- |
-- Generated from template tb_template.vhdl by hexconv.pl |
-------------------------------------------------------------------------------- |
-- Light8080 simulation test bench. |
-------------------------------------------------------------------------------- |
-- Source for the 8080 program is in asm\tb1.asm |
-------------------------------------------------------------------------------- |
-- |
-- This test bench provides a simulated CPU system to test programs. This test |
-- bench does not do any assertions or checks, all assertions are left to the |
-- software. |
-- |
-- The simulated environment has 2KB of RAM, mirror-mapped to all the memory |
-- map of the 8080, initialized with the test program object code. See the perl |
-- script 'util\hexconv.pl' and BAT files in the asm directory. |
-- |
-- Besides, it provides some means to trigger hardware irq from software, |
-- including the specification of the instructions fed to the CPU as interrupt |
-- vectors during inta cycles. |
-- |
-- We will simulate 8 possible irq sources. The software can trigger any one of |
-- them by writing at registers 0x010 and 0x011. Register 0x010 holds the irq |
-- source to be triggered (0 to 7) and register 0x011 holds the number of clock |
-- cycles that will elapse from the end of the instruction that writes to the |
-- register to the assertion of intr. |
-- |
-- When the interrupt is acknowledged and inta is asserted, the test bench reads |
-- the value at register 0x010 as the irq source, and feeds an instruction to |
-- the CPU starting from the RAM address 0040h+source*4. |
-- That is, address range 0040h-005fh is reserved for the simulated 'interrupt |
-- vectors', a total of 4 bytes for each of the 8 sources. This allows the |
-- software to easily test different interrupt vectors without any hand |
-- assembly. All of this is strictly simulation-only stuff. |
-- |
-- |
-- Upon completion, the software must write a value to register 0x020. Writing |
-- a 0x055 means 'success', writing a 0x0aa means 'failure'. Success and |
-- failure conditions are defined by the software. |
-------------------------------------------------------------------------------- |
|
library ieee; |
use ieee.std_logic_1164.ALL; |
use ieee.std_logic_unsigned.all; |
use ieee.numeric_std.ALL; |
|
entity light8080_tb1 is |
end entity light8080_tb1; |
|
architecture behavior of light8080_tb1 is |
|
-------------------------------------------------------------------------------- |
-- Simulation parameters |
|
-- T: simulated clock period |
constant T : time := 100 ns; |
|
-- MAX_SIM_LENGTH: maximum simulation time |
constant MAX_SIM_LENGTH : time := T*5000; |
|
|
-------------------------------------------------------------------------------- |
|
-- Component Declaration for the Unit Under Test (UUT) |
component light8080 |
port ( |
addr_out : out std_logic_vector(15 downto 0); |
|
inta : out std_logic; |
inte : out std_logic; |
halt : out std_logic; |
intr : in std_logic; |
|
vma : out std_logic; |
io : out std_logic; |
rd : out std_logic; |
wr : out std_logic; |
fetch : out std_logic; |
data_in : in std_logic_vector(7 downto 0); |
data_out : out std_logic_vector(7 downto 0); |
|
clk : in std_logic; |
reset : in std_logic ); |
end component; |
|
|
signal data_i : std_logic_vector(7 downto 0) := (others=>'0'); |
signal vma_o : std_logic; |
signal rd_o : std_logic; |
signal wr_o : std_logic; |
signal io_o : std_logic; |
signal data_o : std_logic_vector(7 downto 0); |
signal data_mem : std_logic_vector(7 downto 0); |
signal addr_o : std_logic_vector(15 downto 0); |
signal fetch_o : std_logic; |
signal inta_o : std_logic; |
signal inte_o : std_logic; |
signal intr_i : std_logic := '0'; |
signal halt_o : std_logic; |
|
signal reset : std_logic := '0'; |
signal clk : std_logic := '1'; |
signal done : std_logic := '0'; |
|
type t_rom is array(0 to 2047) of std_logic_vector(7 downto 0); |
|
signal rom : t_rom := ( |
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X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00" |
|
); |
|
signal irq_vector_byte: std_logic_vector(7 downto 0); |
signal irq_source : integer range 0 to 7; |
signal cycles_to_intr : integer range -10 to 255; |
signal int_vector_index : integer range 0 to 3; |
signal addr_vector_table: integer range 0 to 65535; |
|
begin |
|
-- Instantiate the Unit Under Test (UUT) |
uut: light8080 PORT MAP( |
clk => clk, |
reset => reset, |
vma => vma_o, |
rd => rd_o, |
wr => wr_o, |
io => io_o, |
fetch => fetch_o, |
addr_out => addr_o, |
data_in => data_i, |
data_out => data_o, |
|
intr => intr_i, |
inte => inte_o, |
inta => inta_o, |
halt => halt_o |
); |
|
|
-- clock: run clock until test is done |
clock: |
process(done, clk) |
begin |
if done = '0' then |
clk <= not clk after T/2; |
end if; |
end process clock; |
|
|
-- Drive reset and done |
main_test: |
process |
begin |
-- Assert reset for at least one full clk period |
reset <= '1'; |
wait until clk = '1'; |
wait for T/2; |
reset <= '0'; |
|
-- Remember to 'cut away' the preceding 3 clk semiperiods from |
-- the wait statement... |
wait for (MAX_SIM_LENGTH - T*1.5); |
|
-- Maximum sim time elapsed, assume the program ran away and |
-- stop the clk process asserting 'done' (which will stop the simulation) |
done <= '1'; |
|
assert (done = '1') |
report "Test timed out." |
severity failure; |
|
wait; |
end process main_test; |
|
|
-- Synchronous RAM; 2KB mirrored everywhere |
synchronous_ram: |
process(clk) |
begin |
if (clk'event and clk='1') then |
data_mem <= rom(conv_integer(addr_o(10 downto 0))); |
if wr_o = '1' and addr_o(15 downto 11)="00000" then |
rom(conv_integer(addr_o(10 downto 0))) <= data_o; |
end if; |
end if; |
end process synchronous_ram; |
|
|
irq_trigger_register: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if reset='1' then |
cycles_to_intr <= -10; -- meaning no interrupt pending |
intr_i <= '0'; |
else |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"11" then |
cycles_to_intr <= conv_integer(data_o) + 1; |
else |
if cycles_to_intr >= 0 then |
cycles_to_intr <= cycles_to_intr - 1; |
end if; |
if cycles_to_intr = 0 then |
intr_i <= '1'; |
else |
intr_i <= '0'; |
end if; |
end if; |
end if; |
end if; |
end process irq_trigger_register; |
|
|
irq_source_register: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if reset='1' then |
irq_source <= 0; |
else |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"10" then |
irq_source <= conv_integer(data_o(2 downto 0)); |
end if; |
end if; |
end if; |
end process irq_source_register; |
|
|
-- 'interrupt vector' logic. |
irq_vector_table: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if vma_o = '1' and rd_o='1' then |
if inta_o = '1' then |
int_vector_index <= int_vector_index + 1; |
else |
int_vector_index <= 0; |
end if; |
end if; |
-- this is the address of the byte we'll feed to the CPU |
addr_vector_table <= 64+irq_source*4+int_vector_index; |
end if; |
end process irq_vector_table; |
irq_vector_byte <= rom(addr_vector_table); |
|
data_i <= data_mem when inta_o='0' else irq_vector_byte; |
|
|
test_outcome_register: |
process(clk) |
variable outcome : std_logic_vector(7 downto 0); |
begin |
if (clk'event and clk='1') then |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"20" then |
assert (data_o /= X"55") report "Software reports SUCCESS" severity failure; |
assert (data_o /= X"aa") report "Software reports FAILURE" severity failure; |
assert ((data_o = X"aa") or (data_o = X"55")) |
report "Software reports unexpected outcome value." |
severity failure; |
end if; |
end if; |
end process test_outcome_register; |
|
|
end; |
-------------------------------------------------------------------------------- |
-- Generated from template tb_template.vhdl by hexconv.pl |
-------------------------------------------------------------------------------- |
-- Light8080 simulation test bench. |
-------------------------------------------------------------------------------- |
-- This test bench was built from a generic template. The details on what tests |
-- are performed by this test bench can be found in the assembly source for the |
-- 8080 program, in file asm\tb1.asm. |
-------------------------------------------------------------------------------- |
-- |
-- This test bench provides a simulated CPU system to test programs. This test |
-- bench does not do any assertions or checks, all assertions are left to the |
-- software. |
-- |
-- The simulated environment has 2KB of RAM, mirror-mapped to all the memory |
-- map of the 8080, initialized with the test program object code. See the perl |
-- script 'util\hexconv.pl' and BAT files in the asm directory. |
-- |
-- Besides, it provides some means to trigger hardware irq from software, |
-- including the specification of the instructions fed to the CPU as interrupt |
-- vectors during inta cycles. |
-- |
-- We will simulate 8 possible irq sources. The software can trigger any one of |
-- them by writing at ports 0x010 to 0x011. Port 0x010 holds the irq source to |
-- be triggered (0 to 7) and port 0x011 holds the number of clock cycles that |
-- will elapse from the end of the instruction that writes to the register to |
-- the assertion of intr. Port 0x012 holds the number of cycles intr will remain |
-- high. Intr will be asserted for 1 cycle at least, so writing a 0 here is the |
-- same as writing 1. |
-- |
-- When the interrupt is acknowledged and inta is asserted, the test bench reads |
-- the value at register 0x010 as the irq source, and feeds an instruction to |
-- the CPU starting from the RAM address 0040h+source*4. |
-- That is, address range 0040h-005fh is reserved for the simulated 'interrupt |
-- vectors', a total of 4 bytes for each of the 8 sources. This allows the |
-- software to easily test different interrupt vectors without any hand |
-- assembly. All of this is strictly simulation-only stuff. |
-- |
-- Upon completion, the software must write a value to register 0x020. Writing |
-- a 0x055 means 'success', writing a 0x0aa means 'failure'. The write operation |
-- will stop the simulation. Success and failure conditions are defined by the |
-- software. |
-- |
-- If a time period defined as constant MAX_SIM_LENGTH passes before anything |
-- is written to io address 0x020, the test bench assumes the software ran away |
-- and quits with an error message. |
-------------------------------------------------------------------------------- |
|
library ieee; |
use ieee.std_logic_1164.ALL; |
use ieee.std_logic_unsigned.all; |
use ieee.numeric_std.ALL; |
|
entity light8080_tb1 is |
end entity light8080_tb1; |
|
architecture behavior of light8080_tb1 is |
|
-------------------------------------------------------------------------------- |
-- Simulation parameters |
|
-- T: simulated clock period |
constant T : time := 100 ns; |
|
-- MAX_SIM_LENGTH: maximum simulation time |
constant MAX_SIM_LENGTH : time := T*7000; -- enough for the tb0 |
|
|
-------------------------------------------------------------------------------- |
|
-- Component Declaration for the Unit Under Test (UUT) |
component light8080 |
port ( |
addr_out : out std_logic_vector(15 downto 0); |
|
inta : out std_logic; |
inte : out std_logic; |
halt : out std_logic; |
intr : in std_logic; |
|
vma : out std_logic; |
io : out std_logic; |
rd : out std_logic; |
wr : out std_logic; |
fetch : out std_logic; |
data_in : in std_logic_vector(7 downto 0); |
data_out : out std_logic_vector(7 downto 0); |
|
clk : in std_logic; |
reset : in std_logic ); |
end component; |
|
|
signal data_i : std_logic_vector(7 downto 0) := (others=>'0'); |
signal vma_o : std_logic; |
signal rd_o : std_logic; |
signal wr_o : std_logic; |
signal io_o : std_logic; |
signal data_o : std_logic_vector(7 downto 0); |
signal data_mem : std_logic_vector(7 downto 0); |
signal addr_o : std_logic_vector(15 downto 0); |
signal fetch_o : std_logic; |
signal inta_o : std_logic; |
signal inte_o : std_logic; |
signal intr_i : std_logic := '0'; |
signal halt_o : std_logic; |
|
signal reset : std_logic := '0'; |
signal clk : std_logic := '1'; |
signal done : std_logic := '0'; |
|
type t_rom is array(0 to 2047) of std_logic_vector(7 downto 0); |
|
signal rom : t_rom := ( |
|
X"c3",X"60",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"c6",X"01",X"fb",X"c9",X"00",X"00",X"00",X"00", |
X"3c",X"fb",X"c9",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"3c",X"00",X"00",X"00",X"ef",X"00",X"00",X"00", |
X"23",X"00",X"00",X"00",X"3e",X"42",X"00",X"00", |
X"21",X"34",X"12",X"00",X"c3",X"2f",X"01",X"00", |
X"cd",X"34",X"01",X"00",X"cd",X"37",X"01",X"00", |
X"31",X"7a",X"01",X"3e",X"13",X"e7",X"fe",X"14", |
X"c2",X"2a",X"01",X"3e",X"00",X"d3",X"10",X"fb", |
X"3e",X"14",X"d3",X"11",X"3e",X"27",X"00",X"00", |
X"00",X"00",X"fe",X"28",X"c2",X"2a",X"01",X"3e", |
X"01",X"d3",X"10",X"fb",X"3e",X"14",X"d3",X"11", |
X"3e",X"20",X"00",X"00",X"00",X"00",X"fe",X"21", |
X"c2",X"2a",X"01",X"21",X"ff",X"13",X"3e",X"02", |
X"d3",X"10",X"fb",X"3e",X"04",X"d3",X"11",X"00", |
X"00",X"7d",X"fe",X"00",X"c2",X"2a",X"01",X"7c", |
X"fe",X"14",X"c2",X"2a",X"01",X"3e",X"03",X"d3", |
X"10",X"fb",X"3e",X"04",X"d3",X"11",X"00",X"00", |
X"fe",X"42",X"c2",X"2a",X"01",X"3e",X"04",X"d3", |
X"10",X"fb",X"3e",X"04",X"d3",X"11",X"00",X"00", |
X"7c",X"fe",X"12",X"c2",X"2a",X"01",X"7d",X"fe", |
X"34",X"c2",X"2a",X"01",X"3e",X"05",X"d3",X"10", |
X"fb",X"3e",X"04",X"d3",X"11",X"00",X"00",X"fe", |
X"79",X"c2",X"2a",X"01",X"3e",X"06",X"d3",X"10", |
X"fb",X"3e",X"04",X"d3",X"11",X"3c",X"00",X"fe", |
X"05",X"c2",X"2a",X"01",X"78",X"fe",X"19",X"c2", |
X"2a",X"01",X"f3",X"3e",X"07",X"d3",X"10",X"3e", |
X"04",X"d3",X"11",X"00",X"00",X"00",X"3e",X"50", |
X"d3",X"12",X"3e",X"01",X"d3",X"10",X"fb",X"3e", |
X"14",X"d3",X"11",X"3e",X"27",X"00",X"00",X"3c", |
X"00",X"00",X"3c",X"00",X"00",X"00",X"00",X"00", |
X"fe",X"2c",X"c2",X"2a",X"01",X"3e",X"55",X"d3", |
X"20",X"76",X"3e",X"aa",X"d3",X"20",X"76",X"3e", |
X"79",X"c3",X"df",X"00",X"06",X"19",X"c9",X"c3", |
X"2a",X"01",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00", |
X"00",X"00",X"00",X"00",X"00",X"00",X"00",X"00" |
|
); |
|
signal irq_vector_byte: std_logic_vector(7 downto 0); |
signal irq_source : integer range 0 to 7; |
signal cycles_to_intr : integer range -10 to 255; |
signal intr_width : integer range 0 to 255; |
signal int_vector_index : integer range 0 to 3; |
signal addr_vector_table: integer range 0 to 65535; |
|
begin |
|
-- Instantiate the Unit Under Test (UUT) |
uut: light8080 PORT MAP( |
clk => clk, |
reset => reset, |
vma => vma_o, |
rd => rd_o, |
wr => wr_o, |
io => io_o, |
fetch => fetch_o, |
addr_out => addr_o, |
data_in => data_i, |
data_out => data_o, |
|
intr => intr_i, |
inte => inte_o, |
inta => inta_o, |
halt => halt_o |
); |
|
|
-- clock: run clock until test is done |
clock: |
process(done, clk) |
begin |
if done = '0' then |
clk <= not clk after T/2; |
end if; |
end process clock; |
|
|
-- Drive reset and done |
main_test: |
process |
begin |
-- Assert reset for at least one full clk period |
reset <= '1'; |
wait until clk = '1'; |
wait for T/2; |
reset <= '0'; |
|
-- Remember to 'cut away' the preceding 3 clk semiperiods from |
-- the wait statement... |
wait for (MAX_SIM_LENGTH - T*1.5); |
|
-- Maximum sim time elapsed, assume the program ran away and |
-- stop the clk process asserting 'done' (which will stop the simulation) |
done <= '1'; |
|
assert (done = '1') |
report "Test timed out." |
severity failure; |
|
wait; |
end process main_test; |
|
|
-- Synchronous RAM; 2KB mirrored everywhere |
synchronous_ram: |
process(clk) |
begin |
if (clk'event and clk='1') then |
data_mem <= rom(conv_integer(addr_o(10 downto 0))); |
if wr_o = '1' and addr_o(15 downto 11)="00000" then |
rom(conv_integer(addr_o(10 downto 0))) <= data_o; |
end if; |
end if; |
end process synchronous_ram; |
|
|
irq_trigger_register: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if reset='1' then |
cycles_to_intr <= -10; -- meaning no interrupt pending |
else |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"11" then |
cycles_to_intr <= conv_integer(data_o) + 1; |
else |
if cycles_to_intr >= 0 then |
cycles_to_intr <= cycles_to_intr - 1; |
end if; |
end if; |
end if; |
end if; |
end process irq_trigger_register; |
|
irq_pulse_width_register: |
process(clk) |
variable intr_pulse_countdown : integer; |
begin |
if (clk'event and clk='1') then |
if reset='1' then |
intr_width <= 1; |
intr_pulse_countdown := 0; |
intr_i <= '0'; |
else |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"12" then |
intr_width <= conv_integer(data_o) + 1; |
end if; |
|
if cycles_to_intr = 0 then |
intr_i <= '1'; |
intr_pulse_countdown := intr_width; |
elsif intr_pulse_countdown <= 1 then |
intr_i <= '0'; |
else |
intr_pulse_countdown := intr_pulse_countdown - 1; |
end if; |
end if; |
end if; |
end process irq_pulse_width_register; |
|
irq_source_register: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if reset='1' then |
irq_source <= 0; |
else |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"10" then |
irq_source <= conv_integer(data_o(2 downto 0)); |
end if; |
end if; |
end if; |
end process irq_source_register; |
|
|
-- 'interrupt vector' logic. |
irq_vector_table: |
process(clk) |
begin |
if (clk'event and clk='1') then |
if vma_o = '1' and rd_o='1' then |
if inta_o = '1' then |
int_vector_index <= int_vector_index + 1; |
else |
int_vector_index <= 0; |
end if; |
end if; |
-- this is the address of the byte we'll feed to the CPU |
addr_vector_table <= 64+irq_source*4+int_vector_index; |
end if; |
end process irq_vector_table; |
irq_vector_byte <= rom(addr_vector_table); |
|
data_i <= data_mem when inta_o='0' else irq_vector_byte; |
|
|
test_outcome_register: |
process(clk) |
variable outcome : std_logic_vector(7 downto 0); |
begin |
if (clk'event and clk='1') then |
if io_o='1' and wr_o='1' and addr_o(7 downto 0)=X"20" then |
assert (data_o /= X"55") report "Software reports SUCCESS" severity failure; |
assert (data_o /= X"aa") report "Software reports FAILURE" severity failure; |
assert ((data_o = X"aa") or (data_o = X"55")) |
report "Software reports unexpected outcome value." |
severity failure; |
end if; |
end if; |
end process test_outcome_register; |
|
|
end; |