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;