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Reformat loadstore2

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Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
pull/65/head
Anton Blanchard 5 years ago committed by Anton Blanchard
parent e1a71e4545
commit 6e442e07a5
1 changed files with 147 additions and 147 deletions
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294
loadstore2.vhdl
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@ -11,157 +11,157 @@ use work.wishbone_types.all;
-- In this cycle we read or write any data and do sign extension and update if required.

entity loadstore2 is
port (
clk : in std_ulogic;
port (
clk : in std_ulogic;

l_in : in Loadstore1ToLoadstore2Type;
w_out : out Loadstore2ToWritebackType;
l_in : in Loadstore1ToLoadstore2Type;
w_out : out Loadstore2ToWritebackType;

m_in : in wishbone_slave_out;
m_out : out wishbone_master_out
);
m_in : in wishbone_slave_out;
m_out : out wishbone_master_out
);
end loadstore2;

architecture behave of loadstore2 is
signal l_saved : Loadstore1ToLoadstore2Type;
signal w_tmp : Loadstore2ToWritebackType;
signal m_tmp : wishbone_master_out;

type state_t is (IDLE, WAITING_FOR_READ_ACK, WAITING_FOR_WRITE_ACK);
signal state : state_t := IDLE;

function length_to_sel(length : in std_logic_vector(3 downto 0)) return std_ulogic_vector is
begin
case length is
when "0001" =>
return "00000001";
when "0010" =>
return "00000011";
when "0100" =>
return "00001111";
when "1000" =>
return "11111111";
when others =>
return "00000000";
end case;
end function length_to_sel;

function wishbone_data_shift(address : in std_ulogic_vector(63 downto 0)) return natural is
begin
return to_integer(unsigned(address(2 downto 0))) * 8;
end function wishbone_data_shift;

function wishbone_data_sel(size : in std_logic_vector(3 downto 0); address : in std_logic_vector(63 downto 0)) return std_ulogic_vector is
begin
return std_ulogic_vector(shift_left(unsigned(length_to_sel(size)), to_integer(unsigned(address(2 downto 0)))));
end function wishbone_data_sel;
signal l_saved : Loadstore1ToLoadstore2Type;
signal w_tmp : Loadstore2ToWritebackType;
signal m_tmp : wishbone_master_out;

type state_t is (IDLE, WAITING_FOR_READ_ACK, WAITING_FOR_WRITE_ACK);
signal state : state_t := IDLE;

function length_to_sel(length : in std_logic_vector(3 downto 0)) return std_ulogic_vector is
begin
case length is
when "0001" =>
return "00000001";
when "0010" =>
return "00000011";
when "0100" =>
return "00001111";
when "1000" =>
return "11111111";
when others =>
return "00000000";
end case;
end function length_to_sel;

function wishbone_data_shift(address : in std_ulogic_vector(63 downto 0)) return natural is
begin
return to_integer(unsigned(address(2 downto 0))) * 8;
end function wishbone_data_shift;

function wishbone_data_sel(size : in std_logic_vector(3 downto 0); address : in std_logic_vector(63 downto 0)) return std_ulogic_vector is
begin
return std_ulogic_vector(shift_left(unsigned(length_to_sel(size)), to_integer(unsigned(address(2 downto 0)))));
end function wishbone_data_sel;
begin
w_out <= w_tmp;
m_out <= m_tmp;

loadstore2_0: process(clk)
variable tmp : std_ulogic_vector(63 downto 0);
variable data : std_ulogic_vector(63 downto 0);
variable sign_extend_byte_reverse : std_ulogic_vector(1 downto 0);
begin
if rising_edge(clk) then
tmp := (others => '0');
data := (others => '0');

w_tmp <= Loadstore2ToWritebackInit;

l_saved <= l_saved;

case_0: case state is
when IDLE =>
if l_in.valid = '1' then
m_tmp <= wishbone_master_out_init;

m_tmp.sel <= wishbone_data_sel(l_in.length, l_in.addr);
m_tmp.adr <= l_in.addr(63 downto 3) & "000";
m_tmp.cyc <= '1';
m_tmp.stb <= '1';

l_saved <= l_in;

if l_in.load = '1' then
m_tmp.we <= '0';

-- Load with update instructions write two GPR destinations.
-- We don't want the expense of two write ports, so make it
-- single in the pipeline and write back the update GPR now
-- and the load once we get the data back. We'll have to
-- revisit this when loads can take exceptions.
if l_in.update = '1' then
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_in.update_reg;
w_tmp.write_data <= l_in.addr;
end if;

state <= WAITING_FOR_READ_ACK;
else
m_tmp.we <= '1';

data := l_in.data;
m_tmp.dat <= std_logic_vector(shift_left(unsigned(data), wishbone_data_shift(l_in.addr)));

assert l_in.sign_extend = '0' report "sign extension doesn't make sense for stores" severity failure;

state <= WAITING_FOR_WRITE_ACK;
end if;
end if;

when WAITING_FOR_READ_ACK =>
if m_in.ack = '1' then
tmp := std_logic_vector(shift_right(unsigned(m_in.dat), wishbone_data_shift(l_saved.addr)));
case to_integer(unsigned(l_saved.length)) is
when 0 =>
when 1 =>
data(7 downto 0) := tmp(7 downto 0);
when 2 =>
data(15 downto 0) := tmp(15 downto 0);
when 4 =>
data(31 downto 0) := tmp(31 downto 0);
when 8 =>
data(63 downto 0) := tmp(63 downto 0);
when others =>
assert false report "invalid length" severity failure;
end case;

sign_extend_byte_reverse := l_saved.sign_extend & l_saved.byte_reverse;

case sign_extend_byte_reverse is
when "10" =>
data := sign_extend(data, to_integer(unsigned(l_saved.length)));
when "01" =>
data := byte_reverse(data, to_integer(unsigned(l_saved.length)));
when others =>
end case;

w_tmp.write_data <= data;

-- write data to register file
w_tmp.valid <= '1';
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_saved.write_reg;

m_tmp <= wishbone_master_out_init;
state <= IDLE;
end if;

when WAITING_FOR_WRITE_ACK =>
if m_in.ack = '1' then
w_tmp.valid <= '1';
if l_saved.update = '1' then
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_saved.update_reg;
w_tmp.write_data <= l_saved.addr;
end if;

m_tmp <= wishbone_master_out_init;
state <= IDLE;
end if;
end case;
end if;
end process;
w_out <= w_tmp;
m_out <= m_tmp;

loadstore2_0: process(clk)
variable tmp : std_ulogic_vector(63 downto 0);
variable data : std_ulogic_vector(63 downto 0);
variable sign_extend_byte_reverse : std_ulogic_vector(1 downto 0);
begin
if rising_edge(clk) then
tmp := (others => '0');
data := (others => '0');

w_tmp <= Loadstore2ToWritebackInit;

l_saved <= l_saved;

case_0: case state is
when IDLE =>
if l_in.valid = '1' then
m_tmp <= wishbone_master_out_init;

m_tmp.sel <= wishbone_data_sel(l_in.length, l_in.addr);
m_tmp.adr <= l_in.addr(63 downto 3) & "000";
m_tmp.cyc <= '1';
m_tmp.stb <= '1';

l_saved <= l_in;

if l_in.load = '1' then
m_tmp.we <= '0';

-- Load with update instructions write two GPR destinations.
-- We don't want the expense of two write ports, so make it
-- single in the pipeline and write back the update GPR now
-- and the load once we get the data back. We'll have to
-- revisit this when loads can take exceptions.
if l_in.update = '1' then
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_in.update_reg;
w_tmp.write_data <= l_in.addr;
end if;

state <= WAITING_FOR_READ_ACK;
else
m_tmp.we <= '1';

data := l_in.data;
m_tmp.dat <= std_logic_vector(shift_left(unsigned(data), wishbone_data_shift(l_in.addr)));

assert l_in.sign_extend = '0' report "sign extension doesn't make sense for stores" severity failure;

state <= WAITING_FOR_WRITE_ACK;
end if;
end if;

when WAITING_FOR_READ_ACK =>
if m_in.ack = '1' then
tmp := std_logic_vector(shift_right(unsigned(m_in.dat), wishbone_data_shift(l_saved.addr)));
case to_integer(unsigned(l_saved.length)) is
when 0 =>
when 1 =>
data(7 downto 0) := tmp(7 downto 0);
when 2 =>
data(15 downto 0) := tmp(15 downto 0);
when 4 =>
data(31 downto 0) := tmp(31 downto 0);
when 8 =>
data(63 downto 0) := tmp(63 downto 0);
when others =>
assert false report "invalid length" severity failure;
end case;

sign_extend_byte_reverse := l_saved.sign_extend & l_saved.byte_reverse;

case sign_extend_byte_reverse is
when "10" =>
data := sign_extend(data, to_integer(unsigned(l_saved.length)));
when "01" =>
data := byte_reverse(data, to_integer(unsigned(l_saved.length)));
when others =>
end case;

w_tmp.write_data <= data;

-- write data to register file
w_tmp.valid <= '1';
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_saved.write_reg;

m_tmp <= wishbone_master_out_init;
state <= IDLE;
end if;

when WAITING_FOR_WRITE_ACK =>
if m_in.ack = '1' then
w_tmp.valid <= '1';
if l_saved.update = '1' then
w_tmp.write_enable <= '1';
w_tmp.write_reg <= l_saved.update_reg;
w_tmp.write_data <= l_saved.addr;
end if;

m_tmp <= wishbone_master_out_init;
state <= IDLE;
end if;
end case;
end if;
end process;
end;

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