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microwatt/soc.vhdl

761 lines
24 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.math_real.all;
use std.textio.all;
use std.env.stop;
library work;
use work.common.all;
use work.wishbone_types.all;
-- Memory map. *** Keep include/microwatt_soc.h updated on changes ***
--
-- Main bus:
-- 0x00000000: Block RAM (MEMORY_SIZE) or DRAM depending on syscon
-- 0x40000000: DRAM (when present)
-- 0x80000000: Block RAM (aliased & repeated)
-- IO Bus:
-- 0xc0000000: SYSCON
-- 0xc0002000: UART0
-- 0xc0004000: XICS ICP
-- 0xc0005000: XICS ICS
-- 0xc0006000: SPI Flash controller
-- 0xc8nnnnnn: External IO bus
-- 0xf0000000: Flash "ROM" mapping
-- 0xff000000: DRAM init code (if any) or flash ROM (**)
-- External IO bus:
-- 0xc8000000: LiteDRAM control (CSRs)
-- (**) DRAM init code is currently special and goes to the external
-- IO bus, this will be fixed when it's moved out of litedram and
-- into the main SoC once we have a common "firmware".
-- Interrupt numbers:
--
-- 0 : UART0
entity soc is
generic (
MEMORY_SIZE : natural;
RAM_INIT_FILE : string;
CLK_FREQ : positive;
SIM : boolean;
DISABLE_FLATTEN_CORE : boolean := false;
HAS_DRAM : boolean := false;
DRAM_SIZE : integer := 0;
DRAM_INIT_SIZE : integer := 0;
HAS_SPI_FLASH : boolean := false;
SPI_FLASH_DLINES : positive := 1;
SPI_FLASH_OFFSET : integer := 0;
SPI_FLASH_DEF_CKDV : natural := 2;
SPI_FLASH_DEF_QUAD : boolean := false;
LOG_LENGTH : natural := 512
);
port(
rst : in std_ulogic;
system_clk : in std_ulogic;
-- "Large" (64-bit) DRAM wishbone
wb_dram_in : out wishbone_master_out;
wb_dram_out : in wishbone_slave_out := wishbone_slave_out_init;
-- "Small" (32-bit) external IO wishbone
wb_ext_io_in : out wb_io_master_out;
wb_ext_io_out : in wb_io_slave_out := wb_io_slave_out_init;
wb_ext_is_dram_csr : out std_ulogic;
wb_ext_is_dram_init : out std_ulogic;
-- UART0 signals:
uart0_txd : out std_ulogic;
uart0_rxd : in std_ulogic := '0';
-- SPI Flash signals
spi_flash_sck : out std_ulogic;
spi_flash_cs_n : out std_ulogic;
spi_flash_sdat_o : out std_ulogic_vector(SPI_FLASH_DLINES-1 downto 0);
spi_flash_sdat_oe : out std_ulogic_vector(SPI_FLASH_DLINES-1 downto 0);
spi_flash_sdat_i : in std_ulogic_vector(SPI_FLASH_DLINES-1 downto 0) := (others => '1');
-- DRAM controller signals
alt_reset : in std_ulogic := '0'
);
end entity soc;
architecture behaviour of soc is
-- Wishbone master signals:
signal wishbone_dcore_in : wishbone_slave_out;
signal wishbone_dcore_out : wishbone_master_out;
signal wishbone_icore_in : wishbone_slave_out;
signal wishbone_icore_out : wishbone_master_out;
signal wishbone_debug_in : wishbone_slave_out;
signal wishbone_debug_out : wishbone_master_out;
-- Arbiter array (ghdl doesnt' support assigning the array
-- elements in the entity instantiation)
constant NUM_WB_MASTERS : positive := 3;
signal wb_masters_out : wishbone_master_out_vector(0 to NUM_WB_MASTERS-1);
signal wb_masters_in : wishbone_slave_out_vector(0 to NUM_WB_MASTERS-1);
-- Wishbone master (output of arbiter):
signal wb_master_in : wishbone_slave_out;
signal wb_master_out : wishbone_master_out;
-- Main "IO" bus, from main slave decoder to the latch
signal wb_io_in : wishbone_master_out;
signal wb_io_out : wishbone_slave_out;
-- Secondary (smaller) IO bus after the IO bus latch
signal wb_sio_out : wb_io_master_out;
signal wb_sio_in : wb_io_slave_out;
-- Syscon signals
signal dram_at_0 : std_ulogic;
signal do_core_reset : std_ulogic;
signal wb_syscon_in : wb_io_master_out;
signal wb_syscon_out : wb_io_slave_out;
-- UART0 signals:
signal wb_uart0_in : wb_io_master_out;
signal wb_uart0_out : wb_io_slave_out;
signal uart0_dat8 : std_ulogic_vector(7 downto 0);
signal uart0_irq : std_ulogic;
-- SPI Flash controller signals:
signal wb_spiflash_in : wb_io_master_out;
signal wb_spiflash_out : wb_io_slave_out;
signal wb_spiflash_is_reg : std_ulogic;
signal wb_spiflash_is_map : std_ulogic;
-- XICS signals:
signal wb_xics_icp_in : wb_io_master_out;
signal wb_xics_icp_out : wb_io_slave_out;
signal wb_xics_ics_in : wb_io_master_out;
signal wb_xics_ics_out : wb_io_slave_out;
signal int_level_in : std_ulogic_vector(15 downto 0);
signal ics_to_icp : ics_to_icp_t;
signal core_ext_irq : std_ulogic;
-- Main memory signals:
signal wb_bram_in : wishbone_master_out;
signal wb_bram_out : wishbone_slave_out;
-- DMI debug bus signals
signal dmi_addr : std_ulogic_vector(7 downto 0);
signal dmi_din : std_ulogic_vector(63 downto 0);
signal dmi_dout : std_ulogic_vector(63 downto 0);
signal dmi_req : std_ulogic;
signal dmi_wr : std_ulogic;
signal dmi_ack : std_ulogic;
-- Per slave DMI signals
signal dmi_wb_dout : std_ulogic_vector(63 downto 0);
signal dmi_wb_req : std_ulogic;
signal dmi_wb_ack : std_ulogic;
signal dmi_core_dout : std_ulogic_vector(63 downto 0);
signal dmi_core_req : std_ulogic;
signal dmi_core_ack : std_ulogic;
-- Delayed/latched resets and alt_reset
signal rst_core : std_ulogic := '1';
signal rst_uart : std_ulogic := '1';
signal rst_xics : std_ulogic := '1';
signal rst_spi : std_ulogic := '1';
signal rst_bram : std_ulogic := '1';
signal rst_dtm : std_ulogic := '1';
signal rst_wbar : std_ulogic := '1';
signal rst_wbdb : std_ulogic := '1';
signal alt_reset_d : std_ulogic;
-- IO branch split:
type slave_io_type is (SLAVE_IO_SYSCON,
SLAVE_IO_UART,
SLAVE_IO_ICP,
SLAVE_IO_ICS,
SLAVE_IO_SPI_FLASH_REG,
SLAVE_IO_SPI_FLASH_MAP,
SLAVE_IO_EXTERNAL,
SLAVE_IO_NONE);
signal slave_io_dbg : slave_io_type;
begin
resets: process(system_clk)
begin
if rising_edge(system_clk) then
rst_core <= rst or do_core_reset;
rst_uart <= rst;
rst_spi <= rst;
rst_xics <= rst;
rst_bram <= rst;
rst_dtm <= rst;
rst_wbar <= rst;
rst_wbdb <= rst;
alt_reset_d <= alt_reset;
end if;
end process;
-- Processor core
processor: entity work.core
generic map(
SIM => SIM,
DISABLE_FLATTEN => DISABLE_FLATTEN_CORE,
ALT_RESET_ADDRESS => (23 downto 0 => '0', others => '1'),
LOG_LENGTH => LOG_LENGTH
)
port map(
clk => system_clk,
rst => rst_core,
alt_reset => alt_reset_d,
wishbone_insn_in => wishbone_icore_in,
wishbone_insn_out => wishbone_icore_out,
wishbone_data_in => wishbone_dcore_in,
wishbone_data_out => wishbone_dcore_out,
dmi_addr => dmi_addr(3 downto 0),
dmi_dout => dmi_core_dout,
dmi_din => dmi_dout,
dmi_wr => dmi_wr,
dmi_ack => dmi_core_ack,
dmi_req => dmi_core_req,
ext_irq => core_ext_irq
);
-- Wishbone bus master arbiter & mux
wb_masters_out <= (0 => wishbone_dcore_out,
1 => wishbone_icore_out,
2 => wishbone_debug_out);
wishbone_dcore_in <= wb_masters_in(0);
wishbone_icore_in <= wb_masters_in(1);
wishbone_debug_in <= wb_masters_in(2);
wishbone_arbiter_0: entity work.wishbone_arbiter
generic map(
NUM_MASTERS => NUM_WB_MASTERS
)
port map(
clk => system_clk,
rst => rst_wbar,
wb_masters_in => wb_masters_out,
wb_masters_out => wb_masters_in,
wb_slave_out => wb_master_out,
wb_slave_in => wb_master_in
);
-- Top level Wishbone slaves address decoder & mux
--
-- From CPU to BRAM, DRAM, IO, selected on top 3 bits and dram_at_0
-- 0000 - BRAM
-- 0001 - DRAM
-- 01xx - DRAM
-- 10xx - BRAM
-- 11xx - IO
--
slave_top_intercon: process(wb_master_out, wb_bram_out, wb_dram_out, wb_io_out, dram_at_0)
type slave_top_type is (SLAVE_TOP_BRAM,
SLAVE_TOP_DRAM,
SLAVE_TOP_IO);
variable slave_top : slave_top_type;
variable top_decode : std_ulogic_vector(3 downto 0);
begin
-- Top-level address decoder
top_decode := wb_master_out.adr(31 downto 29) & dram_at_0;
slave_top := SLAVE_TOP_BRAM;
if std_match(top_decode, "0000") then
slave_top := SLAVE_TOP_BRAM;
elsif std_match(top_decode, "0001") then
slave_top := SLAVE_TOP_DRAM;
elsif std_match(top_decode, "01--") then
slave_top := SLAVE_TOP_DRAM;
elsif std_match(top_decode, "10--") then
slave_top := SLAVE_TOP_BRAM;
elsif std_match(top_decode, "11--") then
slave_top := SLAVE_TOP_IO;
end if;
-- Top level wishbone muxing.
wb_bram_in <= wb_master_out;
wb_bram_in.cyc <= '0';
wb_dram_in <= wb_master_out;
wb_dram_in.cyc <= '0';
wb_io_in <= wb_master_out;
wb_io_in.cyc <= '0';
case slave_top is
when SLAVE_TOP_BRAM =>
wb_bram_in.cyc <= wb_master_out.cyc;
wb_master_in <= wb_bram_out;
when SLAVE_TOP_DRAM =>
if HAS_DRAM then
wb_dram_in.cyc <= wb_master_out.cyc;
wb_master_in <= wb_dram_out;
else
wb_master_in.ack <= wb_master_out.cyc and wb_master_out.stb;
wb_master_in.dat <= (others => '1');
wb_master_in.stall <= '0';
end if;
when SLAVE_TOP_IO =>
wb_io_in.cyc <= wb_master_out.cyc;
wb_master_in <= wb_io_out;
end case;
end process slave_top_intercon;
-- IO wishbone slave 64->32 bits converter
--
-- For timing reasons, this adds a one cycle latch on the way both
-- in and out. This relaxes timing and routing pressure on the "main"
-- memory bus by moving all simple IOs to a slower 32-bit bus.
--
-- This implementation is rather dumb at the moment, no stash buffer,
-- so we stall whenever that latch is busy. This can be improved.
--
slave_io_latch: process(system_clk)
-- State
type state_t is (IDLE, WAIT_ACK_BOT, WAIT_ACK_TOP);
variable state : state_t;
-- Misc
variable has_top : boolean;
variable has_bot : boolean;
begin
if rising_edge(system_clk) then
if (rst) then
state := IDLE;
wb_io_out.ack <= '0';
wb_io_out.stall <= '0';
wb_sio_out.cyc <= '0';
wb_sio_out.stb <= '0';
has_top := false;
has_bot := false;
else
case state is
when IDLE =>
-- Clear ACK in case it was set
wb_io_out.ack <= '0';
-- Do we have a cycle ?
if wb_io_in.cyc = '1' and wb_io_in.stb = '1' then
-- Stall master until we are done, we are't (yet) pipelining
-- this, it's all slow IOs.
wb_io_out.stall <= '1';
-- Start cycle downstream
wb_sio_out.cyc <= '1';
wb_sio_out.stb <= '1';
-- Copy write enable to IO out, copy address as well
wb_sio_out.we <= wb_io_in.we;
wb_sio_out.adr <= wb_io_in.adr(wb_sio_out.adr'left downto 3) & "000";
-- Do we have a top word and/or a bottom word ?
has_top := wb_io_in.sel(7 downto 4) /= "0000";
has_bot := wb_io_in.sel(3 downto 0) /= "0000";
-- If we have a bottom word, handle it first, otherwise
-- send the top word down. XXX Split the actual mux out
-- and only generate a control signal.
if has_bot then
if wb_io_in.we = '1' then
wb_sio_out.dat <= wb_io_in.dat(31 downto 0);
end if;
wb_sio_out.sel <= wb_io_in.sel(3 downto 0);
-- Wait for ack
state := WAIT_ACK_BOT;
else
if wb_io_in.we = '1' then
wb_sio_out.dat <= wb_io_in.dat(63 downto 32);
end if;
wb_sio_out.sel <= wb_io_in.sel(7 downto 4);
-- Bump address
wb_sio_out.adr(2) <= '1';
-- Wait for ack
state := WAIT_ACK_TOP;
end if;
end if;
when WAIT_ACK_BOT =>
-- If we aren't stalled by the device, clear stb
if wb_sio_in.stall = '0' then
wb_sio_out.stb <= '0';
end if;
-- Handle ack
if wb_sio_in.ack = '1' then
-- If it's a read, latch the data
if wb_sio_out.we = '0' then
wb_io_out.dat(31 downto 0) <= wb_sio_in.dat;
end if;
-- Do we have a "top" part as well ?
if has_top then
-- Latch data & sel
if wb_io_in.we = '1' then
wb_sio_out.dat <= wb_io_in.dat(63 downto 32);
end if;
wb_sio_out.sel <= wb_io_in.sel(7 downto 4);
-- Bump address and set STB
wb_sio_out.adr(2) <= '1';
wb_sio_out.stb <= '1';
-- Wait for new ack
state := WAIT_ACK_TOP;
else
-- We are done, ack up, clear cyc downstram
wb_sio_out.cyc <= '0';
-- And ack & unstall upstream
wb_io_out.ack <= '1';
wb_io_out.stall <= '0';
-- Wait for next one
state := IDLE;
end if;
end if;
when WAIT_ACK_TOP =>
-- If we aren't stalled by the device, clear stb
if wb_sio_in.stall = '0' then
wb_sio_out.stb <= '0';
end if;
-- Handle ack
if wb_sio_in.ack = '1' then
-- If it's a read, latch the data
if wb_sio_out.we = '0' then
wb_io_out.dat(63 downto 32) <= wb_sio_in.dat;
end if;
-- We are done, ack up, clear cyc downstram
wb_sio_out.cyc <= '0';
-- And ack & unstall upstream
wb_io_out.ack <= '1';
wb_io_out.stall <= '0';
-- Wait for next one
state := IDLE;
end if;
end case;
end if;
end if;
end process;
-- IO wishbone slave intercon.
--
slave_io_intercon: process(wb_sio_out, wb_syscon_out, wb_uart0_out,
wb_ext_io_out, wb_xics_icp_out, wb_xics_ics_out,
wb_spiflash_out)
variable slave_io : slave_io_type;
variable match : std_ulogic_vector(31 downto 12);
variable ext_valid : boolean;
begin
-- Simple address decoder.
slave_io := SLAVE_IO_NONE;
match := "11" & wb_sio_out.adr(29 downto 12);
if std_match(match, x"FF---") and HAS_DRAM then
slave_io := SLAVE_IO_EXTERNAL;
elsif std_match(match, x"F----") then
slave_io := SLAVE_IO_SPI_FLASH_MAP;
elsif std_match(match, x"C0000") then
slave_io := SLAVE_IO_SYSCON;
elsif std_match(match, x"C0002") then
slave_io := SLAVE_IO_UART;
elsif std_match(match, x"C8---") then
slave_io := SLAVE_IO_EXTERNAL;
elsif std_match(match, x"C0004") then
slave_io := SLAVE_IO_ICP;
elsif std_match(match, x"C0005") then
slave_io := SLAVE_IO_ICS;
elsif std_match(match, x"C0006") then
slave_io := SLAVE_IO_SPI_FLASH_REG;
end if;
slave_io_dbg <= slave_io;
wb_uart0_in <= wb_sio_out;
wb_uart0_in.cyc <= '0';
wb_spiflash_in <= wb_sio_out;
wb_spiflash_in.cyc <= '0';
wb_spiflash_is_reg <= '0';
wb_spiflash_is_map <= '0';
-- Only give xics 8 bits of wb addr (for now...)
wb_xics_icp_in <= wb_sio_out;
wb_xics_icp_in.adr <= (others => '0');
wb_xics_icp_in.adr(7 downto 0) <= wb_sio_out.adr(7 downto 0);
wb_xics_icp_in.cyc <= '0';
wb_xics_ics_in <= wb_sio_out;
wb_xics_ics_in.adr <= (others => '0');
wb_xics_ics_in.adr(11 downto 0) <= wb_sio_out.adr(11 downto 0);
wb_xics_ics_in.cyc <= '0';
wb_ext_io_in <= wb_sio_out;
wb_ext_io_in.cyc <= '0';
wb_syscon_in <= wb_sio_out;
wb_syscon_in.cyc <= '0';
wb_ext_is_dram_csr <= '0';
wb_ext_is_dram_init <= '0';
-- Default response, ack & return all 1's
wb_sio_in.dat <= (others => '1');
wb_sio_in.ack <= wb_sio_out.stb and wb_sio_out.cyc;
wb_sio_in.stall <= '0';
case slave_io is
when SLAVE_IO_EXTERNAL =>
-- Ext IO "chip selects"
--
-- DRAM init is special at 0xFF* so we just test the top
-- bit. Everything else is at 0xC8* so we test only bits
-- 23 downto 16.
--
ext_valid := false;
if wb_sio_out.adr(29) = '1' and HAS_DRAM then -- DRAM init is special
wb_ext_is_dram_init <= '1';
ext_valid := true;
elsif wb_sio_out.adr(23 downto 16) = x"00" and HAS_DRAM then
wb_ext_is_dram_csr <= '1';
ext_valid := true;
end if;
if ext_valid then
wb_ext_io_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_ext_io_out;
end if;
when SLAVE_IO_SYSCON =>
wb_syscon_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_syscon_out;
when SLAVE_IO_UART =>
wb_uart0_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_uart0_out;
when SLAVE_IO_ICP =>
wb_xics_icp_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_xics_icp_out;
when SLAVE_IO_ICS =>
wb_xics_ics_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_xics_ics_out;
when SLAVE_IO_SPI_FLASH_MAP =>
-- Clear top bits so they don't make their way to the
-- fash chip.
wb_spiflash_in.adr(29 downto 28) <= "00";
wb_spiflash_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_spiflash_out;
wb_spiflash_is_map <= '1';
when SLAVE_IO_SPI_FLASH_REG =>
wb_spiflash_in.cyc <= wb_sio_out.cyc;
wb_sio_in <= wb_spiflash_out;
wb_spiflash_is_reg <= '1';
when others =>
end case;
end process;
-- Syscon slave
syscon0: entity work.syscon
generic map(
HAS_UART => true,
HAS_DRAM => HAS_DRAM,
BRAM_SIZE => MEMORY_SIZE,
DRAM_SIZE => DRAM_SIZE,
DRAM_INIT_SIZE => DRAM_INIT_SIZE,
CLK_FREQ => CLK_FREQ,
HAS_SPI_FLASH => HAS_SPI_FLASH,
SPI_FLASH_OFFSET => SPI_FLASH_OFFSET
)
port map(
clk => system_clk,
rst => rst,
wishbone_in => wb_syscon_in,
wishbone_out => wb_syscon_out,
dram_at_0 => dram_at_0,
core_reset => do_core_reset,
soc_reset => open -- XXX TODO
);
-- Simulated memory and UART
-- UART0 wishbone slave
uart0: entity work.pp_soc_uart
generic map(
FIFO_DEPTH => 32
)
port map(
clk => system_clk,
reset => rst_uart,
txd => uart0_txd,
rxd => uart0_rxd,
irq => uart0_irq,
wb_adr_in => wb_uart0_in.adr(11 downto 0),
wb_dat_in => wb_uart0_in.dat(7 downto 0),
wb_dat_out => uart0_dat8,
wb_cyc_in => wb_uart0_in.cyc,
wb_stb_in => wb_uart0_in.stb,
wb_we_in => wb_uart0_in.we,
wb_ack_out => wb_uart0_out.ack
);
wb_uart0_out.dat <= x"000000" & uart0_dat8;
wb_uart0_out.stall <= not wb_uart0_out.ack;
spiflash_gen: if HAS_SPI_FLASH generate
spiflash: entity work.spi_flash_ctrl
generic map (
DATA_LINES => SPI_FLASH_DLINES,
DEF_CLK_DIV => SPI_FLASH_DEF_CKDV,
DEF_QUAD_READ => SPI_FLASH_DEF_QUAD
)
port map(
rst => rst_spi,
clk => system_clk,
wb_in => wb_spiflash_in,
wb_out => wb_spiflash_out,
wb_sel_reg => wb_spiflash_is_reg,
wb_sel_map => wb_spiflash_is_map,
sck => spi_flash_sck,
cs_n => spi_flash_cs_n,
sdat_o => spi_flash_sdat_o,
sdat_oe => spi_flash_sdat_oe,
sdat_i => spi_flash_sdat_i
);
end generate;
no_spi0_gen: if not HAS_SPI_FLASH generate
wb_spiflash_out.dat <= (others => '1');
wb_spiflash_out.ack <= wb_spiflash_in.cyc and wb_spiflash_in.stb;
wb_spiflash_out.stall <= wb_spiflash_in.cyc and not wb_spiflash_out.ack;
end generate;
xics_icp: entity work.xics_icp
port map(
clk => system_clk,
rst => rst_xics,
wb_in => wb_xics_icp_in,
wb_out => wb_xics_icp_out,
ics_in => ics_to_icp,
core_irq_out => core_ext_irq
);
xics_ics: entity work.xics_ics
generic map(
SRC_NUM => 16
)
port map(
clk => system_clk,
rst => rst_xics,
wb_in => wb_xics_ics_in,
wb_out => wb_xics_ics_out,
int_level_in => int_level_in,
icp_out => ics_to_icp
);
-- Assign external interrupts
interrupts: process(all)
begin
int_level_in <= (others => '0');
int_level_in(0) <= uart0_irq;
end process;
-- BRAM Memory slave
bram: if MEMORY_SIZE /= 0 generate
bram0: entity work.wishbone_bram_wrapper
generic map(
MEMORY_SIZE => MEMORY_SIZE,
RAM_INIT_FILE => RAM_INIT_FILE
)
port map(
clk => system_clk,
rst => rst_bram,
wishbone_in => wb_bram_in,
wishbone_out => wb_bram_out
);
end generate;
no_bram: if MEMORY_SIZE = 0 generate
wb_bram_out.ack <= wb_bram_in.cyc and wb_bram_in.stb;
wb_bram_out.dat <= x"FFFFFFFFFFFFFFFF";
wb_bram_out.stall <= not wb_bram_out.ack;
end generate;
-- DMI(debug bus) <-> JTAG bridge
dtm: entity work.dmi_dtm
generic map(
ABITS => 8,
DBITS => 64
)
port map(
sys_clk => system_clk,
sys_reset => rst_dtm,
dmi_addr => dmi_addr,
dmi_din => dmi_din,
dmi_dout => dmi_dout,
dmi_req => dmi_req,
dmi_wr => dmi_wr,
dmi_ack => dmi_ack
);
-- DMI interconnect
dmi_intercon: process(dmi_addr, dmi_req,
dmi_wb_ack, dmi_wb_dout,
dmi_core_ack, dmi_core_dout)
-- DMI address map (each address is a full 64-bit register)
--
-- Offset: Size: Slave:
-- 0 4 Wishbone
-- 10 16 Core
type slave_type is (SLAVE_WB,
SLAVE_CORE,
SLAVE_NONE);
variable slave : slave_type;
begin
-- Simple address decoder
slave := SLAVE_NONE;
if std_match(dmi_addr, "000000--") then
slave := SLAVE_WB;
elsif std_match(dmi_addr, "0001----") then
slave := SLAVE_CORE;
end if;
-- DMI muxing
dmi_wb_req <= '0';
dmi_core_req <= '0';
case slave is
when SLAVE_WB =>
dmi_wb_req <= dmi_req;
dmi_ack <= dmi_wb_ack;
dmi_din <= dmi_wb_dout;
when SLAVE_CORE =>
dmi_core_req <= dmi_req;
dmi_ack <= dmi_core_ack;
dmi_din <= dmi_core_dout;
when others =>
dmi_ack <= dmi_req;
dmi_din <= (others => '1');
end case;
-- SIM magic exit
if SIM and dmi_req = '1' and dmi_addr = "11111111" and dmi_wr = '1' then
stop;
end if;
end process;
-- Wishbone debug master (TODO: Add a DMI address decoder)
wishbone_debug: entity work.wishbone_debug_master
port map(clk => system_clk,
rst => rst_wbdb,
dmi_addr => dmi_addr(1 downto 0),
dmi_dout => dmi_wb_dout,
dmi_din => dmi_dout,
dmi_wr => dmi_wr,