Subversion Repositories neo430

-- #################################################################################################

-- #  << NEO430 - System Configuration Memory >>                                                   #

-- # ********************************************************************************************* #

-- # This is a read only memory providing information about the processor configuration obtained   #

-- # from the top entity's generics.                                                               #

-- # ********************************************************************************************* #

-- # BSD 3-Clause License                                                                          #

-- #                                                                                               #

-- # Copyright (c) 2020, Stephan Nolting. All rights reserved.                                     #

-- #                                                                                               #

-- # Redistribution and use in source and binary forms, with or without modification, are          #

-- # permitted provided that the following conditions are met:                                     #

-- #                                                                                               #

-- # 1. Redistributions of source code must retain the above copyright notice, this list of        #

-- #    conditions and the following disclaimer.                                                   #

-- #                                                                                               #

-- # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #

-- #    conditions and the following disclaimer in the documentation and/or other materials        #

-- #    provided with the distribution.                                                            #

-- #                                                                                               #

-- # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #

-- #    endorse or promote products derived from this software without specific prior written      #

-- #    permission.                                                                                #

-- #                                                                                               #

-- # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #

-- # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #

-- # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #

-- # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #

-- # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #

-- # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #

-- # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #

-- # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #

-- # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #

-- # ********************************************************************************************* #

-- # The NEO430 Processor - https://github.com/stnolting/neo430                                    #

-- #################################################################################################

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

library neo430;

use neo430.neo430_package.all;

entity neo430_sysconfig is

  generic (

    -- general configuration --

    CLOCK_SPEED  : natural := 100000000; -- main clock in Hz

    IMEM_SIZE    : natural := 4*1024; -- internal IMEM size in bytes

    DMEM_SIZE    : natural := 2*1024; -- internal DMEM size in bytes

    -- additional configuration --

    USER_CODE    : std_ulogic_vector(15 downto 0) := x"0000"; -- custom user code

    -- module configuration --

    MULDIV_USE   : boolean := true; -- implement multiplier/divider unit?

    WB32_USE     : boolean := true; -- implement WB32 unit?

    WDT_USE      : boolean := true; -- implement WDT?

    GPIO_USE     : boolean := true; -- implement GPIO unit?

    TIMER_USE    : boolean := true; -- implement timer?

    UART_USE     : boolean := true; -- implement UART?

    CRC_USE      : boolean := true; -- implement CRC unit?

    CFU_USE      : boolean := true; -- implement CF unit?

    PWM_USE      : boolean := true; -- implement PWM controller?

    TWI_USE      : boolean := true; -- implement TWI?

    SPI_USE      : boolean := true; -- implement SPI?

    TRNG_USE     : boolean := true; -- implement TRNG?

    EXIRQ_USE    : boolean := true; -- implement EXIRQ?

    FREQ_GEN_USE : boolean := true; -- implement FREQ_GEN?

    -- boot configuration --

    BOOTLD_USE   : boolean := true; -- implement and use bootloader?

    IMEM_AS_ROM  : boolean := false -- implement IMEM as read-only memory?

  );

  port (

    clk_i  : in  std_ulogic; -- global clock line

    rden_i : in  std_ulogic; -- read enable

    wren_i : in  std_ulogic; -- write enable

    addr_i : in  std_ulogic_vector(15 downto 0); -- address

    data_i : in  std_ulogic_vector(15 downto 0); -- data in

    data_o : out std_ulogic_vector(15 downto 0)  -- data out

  );

end neo430_sysconfig;

architecture neo430_sysconfig_rtl of neo430_sysconfig is

  -- IO space: module base address --

  constant hi_abb_c : natural := index_size_f(io_size_c)-1; -- high address boundary bit

  constant lo_abb_c : natural := index_size_f(sysconfig_size_c); -- low address boundary bit

  -- access control --

  signal acc_en    : std_ulogic; -- access enable

  signal addr      : std_ulogic_vector(15 downto 0);

  signal rden      : std_ulogic;

  signal info_addr : std_ulogic_vector(02 downto 0);

  -- misc --

  signal f_clk : std_ulogic_vector(31 downto 0);

  -- system information ROM --

  type info_mem_t is array (0 to 7) of std_ulogic_vector(15 downto 0);

  signal sysinfo_mem : info_mem_t; -- ROM

begin

  -- Access Control -----------------------------------------------------------

  -- -----------------------------------------------------------------------------

  acc_en <= '1' when (addr_i(hi_abb_c downto lo_abb_c) = sysconfig_base_c(hi_abb_c downto lo_abb_c)) else '0';

  addr   <= sysconfig_base_c(15 downto lo_abb_c) & addr_i(lo_abb_c-1 downto 1) & '0'; -- word aligned

  rden   <= acc_en and rden_i;

  info_addr <= addr(index_size_f(sysconfig_size_c)-1 downto 1);

  -- Construct Info ROM -------------------------------------------------------

  -- -----------------------------------------------------------------------------

  -- CPUID0: HW version --

  sysinfo_mem(0) <= hw_version_c; -- HW version

  -- CPUID1: System setup (available HW units / IO / peripheral devices) --

  sysinfo_mem(1)(00) <= '1' when (MULDIV_USE   = true) else '0'; -- MULDIV present?

  sysinfo_mem(1)(01) <= '1' when (WB32_USE     = true) else '0'; -- WB32 present?

  sysinfo_mem(1)(02) <= '1' when (WDT_USE      = true) else '0'; -- WDT present?

  sysinfo_mem(1)(03) <= '1' when (GPIO_USE     = true) else '0'; -- GPIO present?

  sysinfo_mem(1)(04) <= '1' when (TIMER_USE    = true) else '0'; -- TIMER present?

  sysinfo_mem(1)(05) <= '1' when (UART_USE     = true) else '0'; -- UART present?

  sysinfo_mem(1)(06) <= '1' when (FREQ_GEN_USE = true) else '0'; -- FREQ_GEN present?

  sysinfo_mem(1)(07) <= '1' when (BOOTLD_USE   = true) else '0'; -- bootloader present?

  sysinfo_mem(1)(08) <= '1' when (IMEM_AS_ROM  = true) else '0'; -- IMEM implemented as true ROM?

  sysinfo_mem(1)(09) <= '1' when (CRC_USE      = true) else '0'; -- CRC present?

  sysinfo_mem(1)(10) <= '1' when (CFU_USE      = true) else '0'; -- CFU present?

  sysinfo_mem(1)(11) <= '1' when (PWM_USE      = true) else '0'; -- PWM present?

  sysinfo_mem(1)(12) <= '1' when (TWI_USE      = true) else '0'; -- TWI present?

  sysinfo_mem(1)(13) <= '1' when (SPI_USE      = true) else '0'; -- SPI present?

  sysinfo_mem(1)(14) <= '1' when (TRNG_USE     = true) else '0'; -- TRNG present?

  sysinfo_mem(1)(15) <= '1' when (EXIRQ_USE    = true) else '0'; -- EXIRQ present?

  -- CPUID2: User code --

  sysinfo_mem(2) <= USER_CODE;

  -- CPUID3: IMEM (ROM/RAM) size --

  sysinfo_mem(3) <= std_ulogic_vector(to_unsigned(IMEM_SIZE, 16)); -- size in bytes

  -- CPUID4: Advanced hardware configuration --

  sysinfo_mem(4)(00) <= '1' when (use_dsp_mul_c    = true) else '0'; -- use DSP blocks for MULDIV.multiplier

  sysinfo_mem(4)(01) <= '1' when (use_xalu_c       = true) else '0'; -- implement eXtended ALU functions

  sysinfo_mem(4)(02) <= '1' when (low_power_mode_c = true) else '0'; -- use (experimental) low-power mode

  sysinfo_mem(4)(15 downto 03) <= (others => '0'); -- reserved

  -- CPUID5: DMEM (RAM) size --

  sysinfo_mem(5) <= std_ulogic_vector(to_unsigned(DMEM_SIZE, 16)); -- size in bytes

  -- CPUID6/CPUID7: Clock speed --

  f_clk <= std_ulogic_vector(to_unsigned(CLOCK_SPEED, 32));

  sysinfo_mem(6) <= f_clk(15 downto 00); -- clock speed LO

  sysinfo_mem(7) <= f_clk(31 downto 16); -- clock speed HI

  -- Read Access --------------------------------------------------------------

  -- -----------------------------------------------------------------------------

  read_access: process(clk_i)

  begin

    if rising_edge(clk_i) then

      if (rden = '1') then

        data_o <= sysinfo_mem(to_integer(unsigned(info_addr)));

      else

        data_o <= (others => '0');

      end if;

    end if;

  end process read_access;

end neo430_sysconfig_rtl;