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antonblanchard.microwatt/core.vhdl
Benjamin Herrenschmidt e4f475e17f sprs: Store common SPRs in register file
This stores the most common SPRs in the register file.

This includes CTR and LR and a not yet final list of others.

The register file is set to 64 entries for now. Specific types
are defined that can represent a GPR index (gpr_index_t) or
a GPR/SPR index (gspr_index_t) along with conversion functions
between the two.

On order to deal with some forms of branch updating both LR and
CTR, we introduced a delayed update of LR after a branch link.

Note: We currently stall the pipeline on such a delayed branch,
but we could avoid stalling fetch in that specific case as we
know we have a branch delay. We could also limit that to the
specific case where we need to update both CTR and LR.

This allows us to make bcreg, mtspr and mfspr pipelined. decode1
will automatically force the single issue flag on mfspr/mtspr to
a "slow" SPR.

[paulus@ozlabs.org - fix direction of decode2.stall_in]

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-12-07 15:30:40 +11:00

307 lines
9.2 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
library work;
use work.common.all;
use work.wishbone_types.all;
entity core is
generic (
SIM : boolean := false;
DISABLE_FLATTEN : boolean := false
);
port (
clk : in std_logic;
rst : in std_logic;
wishbone_insn_in : in wishbone_slave_out;
wishbone_insn_out : out wishbone_master_out;
wishbone_data_in : in wishbone_slave_out;
wishbone_data_out : out wishbone_master_out;
dmi_addr : in std_ulogic_vector(3 downto 0);
dmi_din : in std_ulogic_vector(63 downto 0);
dmi_dout : out std_ulogic_vector(63 downto 0);
dmi_req : in std_ulogic;
dmi_wr : in std_ulogic;
dmi_ack : out std_ulogic;
terminated_out : out std_logic
);
end core;
architecture behave of core is
-- fetch signals
signal fetch2_to_decode1: Fetch2ToDecode1Type;
-- icache signals
signal fetch1_to_icache : Fetch1ToIcacheType;
signal icache_to_fetch2 : IcacheToFetch2Type;
-- decode signals
signal decode1_to_decode2: Decode1ToDecode2Type;
signal decode2_to_execute1: Decode2ToExecute1Type;
-- register file signals
signal register_file_to_decode2: RegisterFileToDecode2Type;
signal decode2_to_register_file: Decode2ToRegisterFileType;
signal writeback_to_register_file: WritebackToRegisterFileType;
-- CR file signals
signal decode2_to_cr_file: Decode2ToCrFileType;
signal cr_file_to_decode2: CrFileToDecode2Type;
signal writeback_to_cr_file: WritebackToCrFileType;
-- execute signals
signal execute1_to_writeback: Execute1ToWritebackType;
signal execute1_to_fetch1: Execute1ToFetch1Type;
-- load store signals
signal decode2_to_loadstore1: Decode2ToLoadstore1Type;
signal loadstore1_to_dcache: Loadstore1ToDcacheType;
signal dcache_to_writeback: DcacheToWritebackType;
-- multiply signals
signal decode2_to_multiply: Decode2ToMultiplyType;
signal multiply_to_writeback: MultiplyToWritebackType;
-- divider signals
signal decode2_to_divider: Decode2ToDividerType;
signal divider_to_writeback: DividerToWritebackType;
-- local signals
signal fetch1_stall_in : std_ulogic;
signal icache_stall_out : std_ulogic;
signal fetch2_stall_in : std_ulogic;
signal decode1_stall_in : std_ulogic;
signal decode2_stall_in : std_ulogic;
signal decode2_stall_out : std_ulogic;
signal ex1_icache_inval: std_ulogic;
signal ex1_stall_out: std_ulogic;
signal flush: std_ulogic;
signal complete: std_ulogic;
signal terminate: std_ulogic;
signal core_rst: std_ulogic;
signal icache_rst: std_ulogic;
-- Debug actions
signal dbg_core_stop: std_ulogic;
signal dbg_core_rst: std_ulogic;
signal dbg_icache_rst: std_ulogic;
-- Debug status
signal dbg_core_is_stopped: std_ulogic;
function keep_h(disable : boolean) return string is
begin
if disable then
return "yes";
else
return "no";
end if;
end function;
attribute keep_hierarchy : string;
attribute keep_hierarchy of fetch1_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of icache_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of fetch2_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of decode1_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of decode2_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of register_file_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of cr_file_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of execute1_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of multiply_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of divider_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of loadstore1_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of dcache_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of writeback_0 : label is keep_h(DISABLE_FLATTEN);
attribute keep_hierarchy of debug_0 : label is keep_h(DISABLE_FLATTEN);
begin
core_rst <= dbg_core_rst or rst;
fetch1_0: entity work.fetch1
generic map (
RESET_ADDRESS => (others => '0')
)
port map (
clk => clk,
rst => core_rst,
stall_in => fetch1_stall_in,
flush_in => flush,
stop_in => dbg_core_stop,
e_in => execute1_to_fetch1,
i_out => fetch1_to_icache
);
fetch1_stall_in <= icache_stall_out or decode2_stall_out;
icache_0: entity work.icache
generic map(
LINE_SIZE => 64,
NUM_LINES => 32,
NUM_WAYS => 2
)
port map(
clk => clk,
rst => icache_rst,
i_in => fetch1_to_icache,
i_out => icache_to_fetch2,
flush_in => flush,
stall_out => icache_stall_out,
wishbone_out => wishbone_insn_out,
wishbone_in => wishbone_insn_in
);
icache_rst <= rst or dbg_icache_rst or ex1_icache_inval;
fetch2_0: entity work.fetch2
port map (
clk => clk,
rst => core_rst,
stall_in => fetch2_stall_in,
flush_in => flush,
i_in => icache_to_fetch2,
f_out => fetch2_to_decode1
);
fetch2_stall_in <= decode2_stall_out;
decode1_0: entity work.decode1
port map (
clk => clk,
rst => core_rst,
stall_in => decode1_stall_in,
flush_in => flush,
f_in => fetch2_to_decode1,
d_out => decode1_to_decode2
);
decode1_stall_in <= decode2_stall_out;
decode2_0: entity work.decode2
port map (
clk => clk,
rst => core_rst,
stall_in => decode2_stall_in,
stall_out => decode2_stall_out,
flush_in => flush,
complete_in => complete,
stopped_out => dbg_core_is_stopped,
d_in => decode1_to_decode2,
e_out => decode2_to_execute1,
l_out => decode2_to_loadstore1,
m_out => decode2_to_multiply,
d_out => decode2_to_divider,
r_in => register_file_to_decode2,
r_out => decode2_to_register_file,
c_in => cr_file_to_decode2,
c_out => decode2_to_cr_file
);
decode2_stall_in <= ex1_stall_out;
register_file_0: entity work.register_file
generic map (
SIM => SIM
)
port map (
clk => clk,
d_in => decode2_to_register_file,
d_out => register_file_to_decode2,
w_in => writeback_to_register_file,
sim_dump => terminate
);
cr_file_0: entity work.cr_file
port map (
clk => clk,
d_in => decode2_to_cr_file,
d_out => cr_file_to_decode2,
w_in => writeback_to_cr_file
);
execute1_0: entity work.execute1
port map (
clk => clk,
flush_out => flush,
stall_out => ex1_stall_out,
e_in => decode2_to_execute1,
f_out => execute1_to_fetch1,
e_out => execute1_to_writeback,
icache_inval => ex1_icache_inval,
terminate_out => terminate
);
loadstore1_0: entity work.loadstore1
port map (
clk => clk,
l_in => decode2_to_loadstore1,
l_out => loadstore1_to_dcache
);
dcache_0: entity work.dcache
generic map(
LINE_SIZE => 64,
NUM_LINES => 32,
NUM_WAYS => 2
)
port map (
clk => clk,
rst => core_rst,
d_in => loadstore1_to_dcache,
d_out => dcache_to_writeback,
wishbone_in => wishbone_data_in,
wishbone_out => wishbone_data_out
);
multiply_0: entity work.multiply
port map (
clk => clk,
m_in => decode2_to_multiply,
m_out => multiply_to_writeback
);
divider_0: entity work.divider
port map (
clk => clk,
rst => core_rst,
d_in => decode2_to_divider,
d_out => divider_to_writeback
);
writeback_0: entity work.writeback
port map (
clk => clk,
e_in => execute1_to_writeback,
l_in => dcache_to_writeback,
m_in => multiply_to_writeback,
d_in => divider_to_writeback,
w_out => writeback_to_register_file,
c_out => writeback_to_cr_file,
complete_out => complete
);
debug_0: entity work.core_debug
port map (
clk => clk,
rst => rst,
dmi_addr => dmi_addr,
dmi_din => dmi_din,
dmi_dout => dmi_dout,
dmi_req => dmi_req,
dmi_wr => dmi_wr,
dmi_ack => dmi_ack,
core_stop => dbg_core_stop,
core_rst => dbg_core_rst,
icache_rst => dbg_icache_rst,
terminate => terminate,
core_stopped => dbg_core_is_stopped,
nia => fetch1_to_icache.nia,
terminated_out => terminated_out
);
end behave;