@ -25,7 +25,7 @@ entity litedram_wrapper is
-- Wishbone ports:
wb_in : in wishbone_master_out;
wb_out : out wishbone_slave_out;
wb_is_csr : in std_ulogic;
wb_is_ctrl : in std_ulogic;
wb_is_init : in std_ulogic;
-- Init core serial debug
@ -58,32 +58,39 @@ end entity litedram_wrapper;
architecture behaviour of litedram_wrapper is
component litedram_core port (
clk : in std_ulogic;
rst : in std_ulogic;
pll_locked : out std_ulogic;
ddram_a : out std_ulogic_vector(DRAM_ALINES-1 downto 0);
ddram_ba : out std_ulogic_vector(2 downto 0);
ddram_ras_n : out std_ulogic;
ddram_cas_n : out std_ulogic;
ddram_we_n : out std_ulogic;
ddram_cs_n : out std_ulogic;
ddram_dm : out std_ulogic_vector(1 downto 0);
ddram_dq : inout std_ulogic_vector(15 downto 0);
ddram_dqs_p : inout std_ulogic_vector(1 downto 0);
ddram_dqs_n : inout std_ulogic_vector(1 downto 0);
ddram_clk_p : out std_ulogic;
ddram_clk_n : out std_ulogic;
ddram_cke : out std_ulogic;
ddram_odt : out std_ulogic;
ddram_reset_n : out std_ulogic;
init_done : out std_ulogic;
init_error : out std_ulogic;
user_clk : out std_ulogic;
user_rst : out std_ulogic;
csr_port0_adr : in std_ulogic_vector(13 downto 0);
csr_port0_we : in std_ulogic;
csr_port0_dat_w : in std_ulogic_vector(31 downto 0);
csr_port0_dat_r : out std_ulogic_vector(31 downto 0);
clk : in std_ulogic;
rst : in std_ulogic;
pll_locked : out std_ulogic;
ddram_a : out std_ulogic_vector(DRAM_ALINES-1 downto 0);
ddram_ba : out std_ulogic_vector(2 downto 0);
ddram_ras_n : out std_ulogic;
ddram_cas_n : out std_ulogic;
ddram_we_n : out std_ulogic;
ddram_cs_n : out std_ulogic;
ddram_dm : out std_ulogic_vector(1 downto 0);
ddram_dq : inout std_ulogic_vector(15 downto 0);
ddram_dqs_p : inout std_ulogic_vector(1 downto 0);
ddram_dqs_n : inout std_ulogic_vector(1 downto 0);
ddram_clk_p : out std_ulogic;
ddram_clk_n : out std_ulogic;
ddram_cke : out std_ulogic;
ddram_odt : out std_ulogic;
ddram_reset_n : out std_ulogic;
init_done : out std_ulogic;
init_error : out std_ulogic;
user_clk : out std_ulogic;
user_rst : out std_ulogic;
wb_ctrl_adr : in std_ulogic_vector(29 downto 0);
wb_ctrl_dat_w : in std_ulogic_vector(31 downto 0);
wb_ctrl_dat_r : out std_ulogic_vector(31 downto 0);
wb_ctrl_sel : in std_ulogic_vector(3 downto 0);
wb_ctrl_cyc : in std_ulogic;
wb_ctrl_stb : in std_ulogic;
wb_ctrl_ack : out std_ulogic;
wb_ctrl_we : in std_ulogic;
wb_ctrl_cti : in std_ulogic_vector(2 downto 0);
wb_ctrl_bte : in std_ulogic_vector(1 downto 0);
wb_ctrl_err : out std_ulogic;
user_port_native_0_cmd_valid : in std_ulogic;
user_port_native_0_cmd_ready : out std_ulogic;
user_port_native_0_cmd_we : in std_ulogic;
@ -112,20 +119,19 @@ architecture behaviour of litedram_wrapper is
signal ad3 : std_ulogic;
signal dram_user_reset : std_ulogic;
signal csr_port0_adr : std_ulogic_vector(13 downto 0);
signal csr_port0_we : std_ulogic;
signal csr_port0_dat_w : std_ulogic_vector(31 downto 0);
signal csr_port0_dat_r : std_ulogic_vector(31 downto 0);
signal csr_port_read_comb : std_ulogic_vector(63 downto 0);
signal csr_valid : std_ulogic;
signal csr_write_valid : std_ulogic;
signal wb_ctrl_adr : std_ulogic_vector(29 downto 0);
signal wb_ctrl_dat_w : std_ulogic_vector(31 downto 0);
signal wb_ctrl_dat_r : std_ulogic_vector(31 downto 0);
signal wb_ctrl_sel : std_ulogic_vector(3 downto 0);
signal wb_ctrl_cyc : std_ulogic;
signal wb_ctrl_stb : std_ulogic;
signal wb_ctrl_ack : std_ulogic;
signal wb_ctrl_we : std_ulogic;
signal wb_init_in : wishbone_master_out;
signal wb_init_out : wishbone_slave_out;
type state_t is (CMD, MWRITE, MREAD, CSR);
type state_t is (CMD, MWRITE, MREAD);
signal state : state_t;
constant INIT_RAM_SIZE : integer := 16384;
@ -192,7 +198,7 @@ begin
ad3 <= wb_in.adr(3);
-- DRAM data interface signals
user_port0_cmd_valid <= (wb_in.cyc and wb_in.stb and not wb_is_csr and not wb_is_init)
user_port0_cmd_valid <= (wb_in.cyc and wb_in.stb and not wb_is_ctrl and not wb_is_init)
when state = CMD else '0';
user_port0_cmd_we <= wb_in.we when state = CMD else '0';
user_port0_wdata_valid <= '1' when state = MWRITE else '0';
@ -202,31 +208,28 @@ begin
user_port0_wdata_we <= wb_in.sel & "00000000" when ad3 = '1' else
"00000000" & wb_in.sel;
-- DRAM CSR interface signals. We only support access to the bottom byte
csr_valid <= wb_in.cyc and wb_in.stb and wb_is_csr;
csr_write_valid <= wb_in.we and wb_in.sel(0);
csr_port0_adr <= wb_in.adr(15 downto 2) when wb_is_csr = '1' else (others => '0');
csr_port0_dat_w <= wb_in.dat(31 downto 0);
csr_port0_we <= (csr_valid and csr_write_valid) when state = CMD else '0';
-- DRAM ctrl interface signals
wb_ctrl_adr <= x"0000" & wb_in.adr(15 downto 2);
wb_ctrl_dat_w <= wb_in.dat(31 downto 0);
wb_ctrl_sel <= wb_in.sel(3 downto 0);
wb_ctrl_cyc <= wb_in.cyc and wb_is_ctrl;
wb_ctrl_stb <= wb_in.stb and wb_is_ctrl;
wb_ctrl_we <= wb_in.we;
-- Wishbone out signals
wb_out.ack <= '1' when state = CSR else
wb_out.ack <= wb_ctrl_ack when wb_is_ctrl ='1' else
wb_init_out.ack when wb_is_init = '1' else
user_port0_wdata_ready when state = MWRITE else
user_port0_rdata_valid when state = MREAD else '0';
csr_port_read_comb <= x"00000000" & csr_port0_dat_r;
wb_out.dat <= csr_port_read_comb when wb_is_csr = '1' else
wb_out.dat <= (x"00000000" & wb_ctrl_dat_r) when wb_is_ctrl = '1' else
wb_init_out.dat when wb_is_init = '1' else
user_port0_rdata_data(127 downto 64) when ad3 = '1' else
user_port0_rdata_data(63 downto 0);
-- We don't do pipelining yet.
wb_out.stall <= '0' when wb_in.cyc = '0' else not wb_out.ack;
-- Reset ignored, the reset controller use the pll lock signal,
-- and alternate core reset address set when DRAM is not initialized.
--
system_reset <= '0';
-- Use alternate core reset address set when DRAM is not initialized.
core_alt_reset <= not init_done;
-- State machine
@ -234,14 +237,12 @@ begin
begin
if rising_edge(system_clk) then
if dram_user_reset = '1' then
if system_reset = '1' then
state <= CMD;
else
case state is
when CMD =>
if csr_valid = '1' then
state <= CSR;
elsif (user_port0_cmd_ready and user_port0_cmd_valid) = '1' then
if (user_port0_cmd_ready and user_port0_cmd_valid) = '1' then
state <= MWRITE when wb_in.we = '1' else MREAD;
end if;
when MWRITE =>
@ -252,8 +253,6 @@ begin
if user_port0_rdata_valid = '1' then
state <= CMD;
end if;
when CSR =>
state <= CMD;
end case;
end if;
end if;
@ -282,11 +281,18 @@ begin
init_done => init_done,
init_error => init_error,
user_clk => system_clk,
user_rst => dram_user_reset,
csr_port0_adr => csr_port0_adr,
csr_port0_we => csr_port0_we,
csr_port0_dat_w => csr_port0_dat_w,
csr_port0_dat_r => csr_port0_dat_r,
user_rst => system_reset,
wb_ctrl_adr => wb_ctrl_adr,
wb_ctrl_dat_w => wb_ctrl_dat_w,
wb_ctrl_dat_r => wb_ctrl_dat_r,
wb_ctrl_sel => wb_ctrl_sel,
wb_ctrl_cyc => wb_ctrl_cyc,
wb_ctrl_stb => wb_ctrl_stb,
wb_ctrl_ack => wb_ctrl_ack,
wb_ctrl_we => wb_ctrl_we,
wb_ctrl_cti => "000",
wb_ctrl_bte => "00",
wb_ctrl_err => open,
user_port_native_0_cmd_valid => user_port0_cmd_valid,
user_port_native_0_cmd_ready => user_port0_cmd_ready,
user_port_native_0_cmd_we => user_port0_cmd_we,
Benjamin Herrenschmidt
4 years ago