countzero: Add a testbench

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
jtag-port
Paul Mackerras 5 years ago
parent e527e3a9b7
commit 4396eddc31

@ -3,7 +3,7 @@ GHDLFLAGS=--std=08 -Psim-unisim
CFLAGS=-O2 -Wall

all = core_tb simple_ram_behavioural_tb soc_reset_tb icache_tb multiply_tb dmi_dtm_tb divider_tb \
rotator_tb
rotator_tb countzero_tb

# XXX
# loadstore_tb fetch_tb
@ -19,6 +19,7 @@ core_tb.o: common.o wishbone_types.o core.o soc.o sim_jtag.o
core.o: common.o wishbone_types.o fetch1.o fetch2.o icache.o decode1.o decode2.o register_file.o cr_file.o execute1.o execute2.o loadstore1.o loadstore2.o multiply.o writeback.o core_debug.o divider.o
core_debug.o: common.o
countzero.o:
countzero_tb.o: common.o glibc_random.o countzero.o
cr_file.o: common.o
crhelpers.o: common.o
decode1.o: common.o decode_types.o
@ -95,6 +96,9 @@ divider_tb: divider_tb.o
rotator_tb: rotator_tb.o
$(GHDL) -e $(GHDLFLAGS) $@

countzero_tb: countzero_tb.o
$(GHDL) -e $(GHDLFLAGS) $@

simple_ram_tb: simple_ram_tb.o
$(GHDL) -e $(GHDLFLAGS) $@


@ -0,0 +1,105 @@
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

library work;
use work.common.all;
use work.glibc_random.all;

entity countzero_tb is
end countzero_tb;

architecture behave of countzero_tb is
constant clk_period: time := 10 ns;
signal rs: std_ulogic_vector(63 downto 0);
signal is_32bit, count_right: std_ulogic := '0';
signal result: std_ulogic_vector(63 downto 0);
signal randno: std_ulogic_vector(63 downto 0);

begin
zerocounter_0: entity work.zero_counter
port map (
rs => rs,
result => result,
count_right => count_right,
is_32bit => is_32bit
);

stim_process: process
variable r: std_ulogic_vector(63 downto 0);
begin
-- test with input = 0
report "test zero input";
rs <= (others => '0');
is_32bit <= '0';
count_right <= '0';
wait for clk_period;
assert result = x"0000000000000040"
report "bad cntlzd 0 = " & to_hstring(result);
count_right <= '1';
wait for clk_period;
assert result = x"0000000000000040"
report "bad cnttzd 0 = " & to_hstring(result);
is_32bit <= '1';
count_right <= '0';
wait for clk_period;
assert result = x"0000000000000020"
report "bad cntlzw 0 = " & to_hstring(result);
count_right <= '1';
wait for clk_period;
assert result = x"0000000000000020"
report "bad cnttzw 0 = " & to_hstring(result);

report "test cntlzd/w";
count_right <= '0';
for j in 0 to 100 loop
r := pseudorand(64);
r(63) := '1';
for i in 0 to 63 loop
rs <= r;
is_32bit <= '0';
wait for clk_period;
assert to_integer(unsigned(result)) = i
report "bad cntlzd " & to_hstring(rs) & " -> " & to_hstring(result);
rs <= r(31 downto 0) & r(63 downto 32);
is_32bit <= '1';
wait for clk_period;
if i < 32 then
assert to_integer(unsigned(result)) = i
report "bad cntlzw " & to_hstring(rs) & " -> " & to_hstring(result);
else
assert to_integer(unsigned(result)) = 32
report "bad cntlzw " & to_hstring(rs) & " -> " & to_hstring(result);
end if;
r := '0' & r(63 downto 1);
end loop;
end loop;

report "test cnttzd/w";
count_right <= '1';
for j in 0 to 100 loop
r := pseudorand(64);
r(0) := '1';
for i in 0 to 63 loop
rs <= r;
is_32bit <= '0';
wait for clk_period;
assert to_integer(unsigned(result)) = i
report "bad cnttzd " & to_hstring(rs) & " -> " & to_hstring(result);
is_32bit <= '1';
wait for clk_period;
if i < 32 then
assert to_integer(unsigned(result)) = i
report "bad cnttzw " & to_hstring(rs) & " -> " & to_hstring(result);
else
assert to_integer(unsigned(result)) = 32
report "bad cnttzw " & to_hstring(rs) & " -> " & to_hstring(result);
end if;
r := r(62 downto 0) & '0';
end loop;
end loop;

assert false report "end of test" severity failure;
wait;
end process;
end behave;
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