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-- #################################################################################################
-- # << NEORV32 - Main VHDL package file >>                                                        #
-- # ********************************************************************************************* #
-- # 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 NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
-- #################################################################################################
 
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
 
package neorv32_package is
 
  -- Architecture Constants -----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant data_width_c  : natural := 32; -- data width - FIXED!
  constant hw_version_c  : std_ulogic_vector(31 downto 0) := x"01040000"; -- no touchy!
  constant pmp_max_r_c   : natural := 8; -- max PMP regions
  constant ipb_entries_c : natural := 2; -- entries in instruction prefetch buffer, must be a power of 2, default=2
 
  -- Helper Functions -----------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function index_size_f(input : natural) return natural;
  function cond_sel_natural_f(cond : boolean; val_t : natural; val_f : natural) return natural;
  function cond_sel_stdulogicvector_f(cond : boolean; val_t : std_ulogic_vector; val_f : std_ulogic_vector) return std_ulogic_vector;
  function bool_to_ulogic_f(cond : boolean) return std_ulogic;
  function or_all_f(a : std_ulogic_vector) return std_ulogic;
  function and_all_f(a : std_ulogic_vector) return std_ulogic;
  function xor_all_f(a : std_ulogic_vector) return std_ulogic;
  function xnor_all_f(a : std_ulogic_vector) return std_ulogic;
  function to_hexchar_f(input : std_ulogic_vector(3 downto 0)) return character;
 
  -- Internal Types -------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  type pmp_ctrl_if_t is array (0 to pmp_max_r_c-1) of std_ulogic_vector(7 downto 0);
  type pmp_addr_if_t is array (0 to pmp_max_r_c-1) of std_ulogic_vector(33 downto 0);
 
  -- Processor-internal Address Space Layout ------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- Instruction Memory & Data Memory --
  -- => configured via top's generics
 
  -- Bootloader ROM --
  constant boot_base_c          : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFF0000"; -- bootloader base address, fixed!
  constant boot_size_c          : natural := 4*1024; -- bytes
  constant boot_max_size_c      : natural := 32*1024; -- bytes, fixed!
 
  -- IO: Peripheral Devices ("IO") Area --
  -- Control register(s) (including the device-enable) should be located at the base address of each device
  constant io_base_c            : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFF80";
  constant io_size_c            : natural := 32*4; -- bytes, fixed!
 
  -- General Purpose Input/Output Unit (GPIO) --
  constant gpio_base_c          : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFF80"; -- base address, fixed!
  constant gpio_size_c          : natural := 2*4; -- bytes, fixed!
  constant gpio_in_addr_c       : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(gpio_base_c) + x"00000000");
  constant gpio_out_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(gpio_base_c) + x"00000004");
 
  -- Dummy Device (with SIMULATION output) (DEVNULL) --
  constant devnull_base_c       : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFF88"; -- base address, fixed!
  constant devnull_size_c       : natural := 1*4; -- bytes, fixed!
  constant devnull_data_addr_c  : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(devnull_base_c) + x"00000000");
 
  -- Watch Dog Timer (WDT) --
  constant wdt_base_c           : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFF8C"; -- base address, fixed!
  constant wdt_size_c           : natural := 1*4; -- bytes, fixed!
  constant wdt_ctrl_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(wdt_base_c) + x"00000000");
 
  -- Machine System Timer (MTIME) --
  constant mtime_base_c         : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFF90"; -- base address, fixed!
  constant mtime_size_c         : natural := 4*4; -- bytes, fixed!
  constant mtime_time_lo_addr_c : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(mtime_base_c) + x"00000000");
  constant mtime_time_hi_addr_c : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(mtime_base_c) + x"00000004");
  constant mtime_cmp_lo_addr_c  : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(mtime_base_c) + x"00000008");
  constant mtime_cmp_hi_addr_c  : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(mtime_base_c) + x"0000000C");
 
  -- Universal Asynchronous Receiver/Transmitter (UART) --
  constant uart_base_c          : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFA0"; -- base address, fixed!
  constant uart_size_c          : natural := 2*4; -- bytes, fixed!
  constant uart_ctrl_addr_c     : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(uart_base_c) + x"00000000");
  constant uart_rtx_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(uart_base_c) + x"00000004");
 
  -- Serial Peripheral Interface (SPI) --
  constant spi_base_c           : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFA8"; -- base address, fixed!
  constant spi_size_c           : natural := 2*4; -- bytes, fixed!
  constant spi_ctrl_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(spi_base_c) + x"00000000");
  constant spi_rtx_addr_c       : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(spi_base_c) + x"00000004");
 
  -- Two Wire Interface (TWI) --
  constant twi_base_c           : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFB0"; -- base address, fixed!
  constant twi_size_c           : natural := 2*4; -- bytes, fixed!
  constant twi_ctrl_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(twi_base_c) + x"00000000");
  constant twi_rtx_addr_c       : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(twi_base_c) + x"00000004");
 
  -- Pulse-Width Modulation Controller (PWM) --
  constant pwm_base_c           : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFB8"; -- base address, fixed!
  constant pwm_size_c           : natural := 2*4; -- bytes, fixed!
  constant pwm_ctrl_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(pwm_base_c) + x"00000000");
  constant pwm_duty_addr_c      : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(pwm_base_c) + x"00000004");
 
  -- True Random Number generator (TRNG) --
  constant trng_base_c          : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFC0"; -- base address, fixed!
  constant trng_size_c          : natural := 2*4; -- bytes, fixed!
  constant trng_ctrl_addr_c     : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(trng_base_c) + x"00000000");
  constant trng_data_addr_c     : std_ulogic_vector(31 downto 0) := std_ulogic_vector(unsigned(trng_base_c) + x"00000004");
 
  -- RESERVED --
--constant ???_base_c           : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFC8"; -- base address, fixed!
--constant ???_size_c           : natural := 6*4; -- bytes, fixed!
 
  -- System Information Memory (with SIMULATION output) (SYSINFO) --
  constant sysinfo_base_c       : std_ulogic_vector(data_width_c-1 downto 0) := x"FFFFFFE0"; -- base address, fixed!
  constant sysinfo_size_c       : natural := 8*4; -- bytes, fixed!
 
  -- Main Control Bus -----------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- register file --
  constant ctrl_rf_in_mux_lsb_c   : natural :=  0; -- input source select lsb (00=ALU, 01=MEM)
  constant ctrl_rf_in_mux_msb_c   : natural :=  1; -- input source select msb (10=PC,  11=CSR)
  constant ctrl_rf_rs1_adr0_c     : natural :=  2; -- source register 1 address bit 0
  constant ctrl_rf_rs1_adr1_c     : natural :=  3; -- source register 1 address bit 1
  constant ctrl_rf_rs1_adr2_c     : natural :=  4; -- source register 1 address bit 2
  constant ctrl_rf_rs1_adr3_c     : natural :=  5; -- source register 1 address bit 3
  constant ctrl_rf_rs1_adr4_c     : natural :=  6; -- source register 1 address bit 4
  constant ctrl_rf_rs2_adr0_c     : natural :=  7; -- source register 2 address bit 0
  constant ctrl_rf_rs2_adr1_c     : natural :=  8; -- source register 2 address bit 1
  constant ctrl_rf_rs2_adr2_c     : natural :=  9; -- source register 2 address bit 2
  constant ctrl_rf_rs2_adr3_c     : natural := 10; -- source register 2 address bit 3
  constant ctrl_rf_rs2_adr4_c     : natural := 11; -- source register 2 address bit 4
  constant ctrl_rf_rd_adr0_c      : natural := 12; -- destiantion register address bit 0
  constant ctrl_rf_rd_adr1_c      : natural := 13; -- destiantion register address bit 1
  constant ctrl_rf_rd_adr2_c      : natural := 14; -- destiantion register address bit 2
  constant ctrl_rf_rd_adr3_c      : natural := 15; -- destiantion register address bit 3
  constant ctrl_rf_rd_adr4_c      : natural := 16; -- destiantion register address bit 4
  constant ctrl_rf_wb_en_c        : natural := 17; -- write back enable
  constant ctrl_rf_clear_rs1_c    : natural := 18; -- force rs1=r0
  constant ctrl_rf_clear_rs2_c    : natural := 19; -- force rs2=r0
  -- alu --
  constant ctrl_alu_cmd0_c        : natural := 20; -- ALU command bit 0
  constant ctrl_alu_cmd1_c        : natural := 21; -- ALU command bit 1
  constant ctrl_alu_cmd2_c        : natural := 22; -- ALU command bit 2
  constant ctrl_alu_opa_mux_lsb_c : natural := 23; -- operand A select lsb (00=rs1, 01=PC)
  constant ctrl_alu_opa_mux_msb_c : natural := 24; -- operand A select msb (1-=CSR)
  constant ctrl_alu_opb_mux_lsb_c : natural := 25; -- operand B select lsb (00=rs2, 01=IMM)
  constant ctrl_alu_opb_mux_msb_c : natural := 26; -- operand B select msb (1-=rs1)
  constant ctrl_alu_opc_mux_c     : natural := 27; -- operand C select (0=IMM, 1=rs2)
  constant ctrl_alu_unsigned_c    : natural := 28; -- is unsigned ALU operation
  constant ctrl_alu_shift_dir_c   : natural := 29; -- shift direction (0=left, 1=right)
  constant ctrl_alu_shift_ar_c    : natural := 30; -- is arithmetic shift
  -- bus interface --
  constant ctrl_bus_size_lsb_c    : natural := 31; -- transfer size lsb (00=byte, 01=half-word)
  constant ctrl_bus_size_msb_c    : natural := 32; -- transfer size msb (10=word, 11=?)
  constant ctrl_bus_rd_c          : natural := 33; -- read data request
  constant ctrl_bus_wr_c          : natural := 34; -- write data request
  constant ctrl_bus_if_c          : natural := 35; -- instruction fetch request
  constant ctrl_bus_mar_we_c      : natural := 36; -- memory address register write enable
  constant ctrl_bus_mdo_we_c      : natural := 37; -- memory data out register write enable
  constant ctrl_bus_mdi_we_c      : natural := 38; -- memory data in register write enable
  constant ctrl_bus_unsigned_c    : natural := 39; -- is unsigned load
  constant ctrl_bus_ierr_ack_c    : natural := 40; -- acknowledge instruction fetch bus exception
  constant ctrl_bus_derr_ack_c    : natural := 41; -- acknowledge data access bus exception
  constant ctrl_bus_fence_c       : natural := 42; -- executed fence operation
  constant ctrl_bus_fencei_c      : natural := 43; -- executed fencei operation
  -- co-processor --
  constant ctrl_cp_use_c          : natural := 44; -- is cp operation
  constant ctrl_cp_id_lsb_c       : natural := 45; -- cp select lsb
  constant ctrl_cp_id_msb_c       : natural := 46; -- cp select msb
  constant ctrl_cp_cmd0_c         : natural := 47; -- cp command bit 0
  constant ctrl_cp_cmd1_c         : natural := 48; -- cp command bit 1
  constant ctrl_cp_cmd2_c         : natural := 49; -- cp command bit 2
  -- control bus size --
  constant ctrl_width_c           : natural := 50; -- control bus size
 
  -- ALU Comparator Bus ---------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant alu_cmp_equal_c : natural := 0;
  constant alu_cmp_less_c  : natural := 1; -- for signed and unsigned comparisons
 
  -- RISC-V Opcode Layout -------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant instr_opcode_lsb_c  : natural :=  0; -- opcode bit 0
  constant instr_opcode_msb_c  : natural :=  6; -- opcode bit 6
  constant instr_rd_lsb_c      : natural :=  7; -- destination register address bit 0
  constant instr_rd_msb_c      : natural := 11; -- destination register address bit 4
  constant instr_funct3_lsb_c  : natural := 12; -- funct3 bit 0
  constant instr_funct3_msb_c  : natural := 14; -- funct3 bit 2
  constant instr_rs1_lsb_c     : natural := 15; -- source register 1 address bit 0
  constant instr_rs1_msb_c     : natural := 19; -- source register 1 address bit 4
  constant instr_rs2_lsb_c     : natural := 20; -- source register 2 address bit 0
  constant instr_rs2_msb_c     : natural := 24; -- source register 2 address bit 4
  constant instr_funct7_lsb_c  : natural := 25; -- funct7 bit 0
  constant instr_funct7_msb_c  : natural := 31; -- funct7 bit 6
  constant instr_funct12_lsb_c : natural := 20; -- funct12 bit 0
  constant instr_funct12_msb_c : natural := 31; -- funct12 bit 11
  constant instr_imm12_lsb_c   : natural := 20; -- immediate12 bit 0
  constant instr_imm12_msb_c   : natural := 31; -- immediate12 bit 11
  constant instr_imm20_lsb_c   : natural := 12; -- immediate20 bit 0
  constant instr_imm20_msb_c   : natural := 31; -- immediate20 bit 21
  constant instr_csr_id_lsb_c  : natural := 20; -- csr select bit 0
  constant instr_csr_id_msb_c  : natural := 31; -- csr select bit 11
 
  -- RISC-V Opcodes -------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- alu --
  constant opcode_lui_c    : std_ulogic_vector(6 downto 0) := "0110111"; -- load upper immediate
  constant opcode_auipc_c  : std_ulogic_vector(6 downto 0) := "0010111"; -- add upper immediate to PC
  constant opcode_alui_c   : std_ulogic_vector(6 downto 0) := "0010011"; -- ALU operation with immediate (operation via funct3 and funct7)
  constant opcode_alu_c    : std_ulogic_vector(6 downto 0) := "0110011"; -- ALU operation (operation via funct3 and funct7)
  -- control flow --
  constant opcode_jal_c    : std_ulogic_vector(6 downto 0) := "1101111"; -- jump and link
  constant opcode_jalr_c   : std_ulogic_vector(6 downto 0) := "1100111"; -- jump and register
  constant opcode_branch_c : std_ulogic_vector(6 downto 0) := "1100011"; -- branch (condition set via funct3)
  -- memory access --
  constant opcode_load_c   : std_ulogic_vector(6 downto 0) := "0000011"; -- load (data type via funct3)
  constant opcode_store_c  : std_ulogic_vector(6 downto 0) := "0100011"; -- store (data type via funct3)
  -- system/csr --
  constant opcode_fence_c  : std_ulogic_vector(6 downto 0) := "0001111"; -- fence / fence.i
  constant opcode_syscsr_c : std_ulogic_vector(6 downto 0) := "1110011"; -- system/csr access (type via funct3)
 
  -- RISC-V Funct3 --------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- control flow --
  constant funct3_beq_c    : std_ulogic_vector(2 downto 0) := "000"; -- branch if equal
  constant funct3_bne_c    : std_ulogic_vector(2 downto 0) := "001"; -- branch if not equal
  constant funct3_blt_c    : std_ulogic_vector(2 downto 0) := "100"; -- branch if less than
  constant funct3_bge_c    : std_ulogic_vector(2 downto 0) := "101"; -- branch if greater than or equal
  constant funct3_bltu_c   : std_ulogic_vector(2 downto 0) := "110"; -- branch if less than (unsigned)
  constant funct3_bgeu_c   : std_ulogic_vector(2 downto 0) := "111"; -- branch if greater than or equal (unsigned)
  -- memory access --
  constant funct3_lb_c     : std_ulogic_vector(2 downto 0) := "000"; -- load byte
  constant funct3_lh_c     : std_ulogic_vector(2 downto 0) := "001"; -- load half word
  constant funct3_lw_c     : std_ulogic_vector(2 downto 0) := "010"; -- load word
  constant funct3_lbu_c    : std_ulogic_vector(2 downto 0) := "100"; -- load byte (unsigned)
  constant funct3_lhu_c    : std_ulogic_vector(2 downto 0) := "101"; -- load half word (unsigned)
  constant funct3_sb_c     : std_ulogic_vector(2 downto 0) := "000"; -- store byte
  constant funct3_sh_c     : std_ulogic_vector(2 downto 0) := "001"; -- store half word
  constant funct3_sw_c     : std_ulogic_vector(2 downto 0) := "010"; -- store word
  -- alu --
  constant funct3_subadd_c : std_ulogic_vector(2 downto 0) := "000"; -- sub/add via funct7
  constant funct3_sll_c    : std_ulogic_vector(2 downto 0) := "001"; -- shift logical left
  constant funct3_slt_c    : std_ulogic_vector(2 downto 0) := "010"; -- set on less
  constant funct3_sltu_c   : std_ulogic_vector(2 downto 0) := "011"; -- set on less unsigned
  constant funct3_xor_c    : std_ulogic_vector(2 downto 0) := "100"; -- xor
  constant funct3_sr_c     : std_ulogic_vector(2 downto 0) := "101"; -- shift right via funct7
  constant funct3_or_c     : std_ulogic_vector(2 downto 0) := "110"; -- or
  constant funct3_and_c    : std_ulogic_vector(2 downto 0) := "111"; -- and
  -- system/csr --
  constant funct3_env_c    : std_ulogic_vector(2 downto 0) := "000"; -- ecall, ebreak, mret, wfi
  constant funct3_csrrw_c  : std_ulogic_vector(2 downto 0) := "001"; -- atomic r/w
  constant funct3_csrrs_c  : std_ulogic_vector(2 downto 0) := "010"; -- atomic read & set bit
  constant funct3_csrrc_c  : std_ulogic_vector(2 downto 0) := "011"; -- atomic read & clear bit
  --
  constant funct3_csrrwi_c : std_ulogic_vector(2 downto 0) := "101"; -- atomic r/w immediate
  constant funct3_csrrsi_c : std_ulogic_vector(2 downto 0) := "110"; -- atomic read & set bit immediate
  constant funct3_csrrci_c : std_ulogic_vector(2 downto 0) := "111"; -- atomic read & clear bit immediate
  -- fence --
  constant funct3_fence_c  : std_ulogic_vector(2 downto 0) := "000"; -- fence - order IO/memory access (->NOP)
  constant funct3_fencei_c : std_ulogic_vector(2 downto 0) := "001"; -- fencei - instructon stream sync
 
  -- RISC-V Funct12 --------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- system --
  constant funct12_ecall_c  : std_ulogic_vector(11 downto 0) := x"000"; -- ECALL
  constant funct12_ebreak_c : std_ulogic_vector(11 downto 0) := x"001"; -- EBREAK
  constant funct12_mret_c   : std_ulogic_vector(11 downto 0) := x"302"; -- MRET
  constant funct12_wfi_c    : std_ulogic_vector(11 downto 0) := x"105"; -- WFI
 
  -- Co-Processor Operations ----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- cp ids --
  constant cp_sel_muldiv_c : std_ulogic_vector(1 downto 0) := "00"; -- MULDIV CP
  -- muldiv cp --
  constant cp_op_mul_c     : std_ulogic_vector(2 downto 0) := "000"; -- mul
  constant cp_op_mulh_c    : std_ulogic_vector(2 downto 0) := "001"; -- mulh
  constant cp_op_mulhsu_c  : std_ulogic_vector(2 downto 0) := "010"; -- mulhsu
  constant cp_op_mulhu_c   : std_ulogic_vector(2 downto 0) := "011"; -- mulhu
  constant cp_op_div_c     : std_ulogic_vector(2 downto 0) := "100"; -- div
  constant cp_op_divu_c    : std_ulogic_vector(2 downto 0) := "101"; -- divu
  constant cp_op_rem_c     : std_ulogic_vector(2 downto 0) := "110"; -- rem
  constant cp_op_remu_c    : std_ulogic_vector(2 downto 0) := "111"; -- remu
 
  -- ALU Function Codes ---------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant alu_cmd_add_c   : std_ulogic_vector(2 downto 0) := "000"; -- r <= A + B
  constant alu_cmd_sub_c   : std_ulogic_vector(2 downto 0) := "001"; -- r <= A - B
  constant alu_cmd_slt_c   : std_ulogic_vector(2 downto 0) := "010"; -- r <= A < B
  constant alu_cmd_shift_c : std_ulogic_vector(2 downto 0) := "011"; -- r <= A <</>> B
  constant alu_cmd_xor_c   : std_ulogic_vector(2 downto 0) := "100"; -- r <= A xor B
  constant alu_cmd_or_c    : std_ulogic_vector(2 downto 0) := "101"; -- r <= A or B
  constant alu_cmd_and_c   : std_ulogic_vector(2 downto 0) := "110"; -- r <= A and B
  constant alu_cmd_bitc_c  : std_ulogic_vector(2 downto 0) := "111"; -- r <= A and (not B)
 
  -- Trap ID Codes --------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- risc-v compliant --
  constant trap_ima_c   : std_ulogic_vector(5 downto 0) := "000000"; -- 0.0:  instruction misaligned
  constant trap_iba_c   : std_ulogic_vector(5 downto 0) := "000001"; -- 0.1:  instruction access fault
  constant trap_iil_c   : std_ulogic_vector(5 downto 0) := "000010"; -- 0.2:  illegal instruction
  constant trap_brk_c   : std_ulogic_vector(5 downto 0) := "000011"; -- 0.3:  breakpoint
  constant trap_lma_c   : std_ulogic_vector(5 downto 0) := "000100"; -- 0.4:  load address misaligned
  constant trap_lbe_c   : std_ulogic_vector(5 downto 0) := "000101"; -- 0.5:  load access fault
  constant trap_sma_c   : std_ulogic_vector(5 downto 0) := "000110"; -- 0.6:  store address misaligned
  constant trap_sbe_c   : std_ulogic_vector(5 downto 0) := "000111"; -- 0.7:  store access fault
  constant trap_menv_c  : std_ulogic_vector(5 downto 0) := "001011"; -- 0.11: environment call from m-mode
  --
  constant trap_msi_c   : std_ulogic_vector(5 downto 0) := "100011"; -- 1.3:  machine software interrupt
  constant trap_mti_c   : std_ulogic_vector(5 downto 0) := "100111"; -- 1.7:  machine timer interrupt
  constant trap_mei_c   : std_ulogic_vector(5 downto 0) := "101011"; -- 1.11: machine external interrupt
  -- custom --
  constant trap_firq0_c : std_ulogic_vector(5 downto 0) := "110000"; -- 1.16: fast interrupt 0
  constant trap_firq1_c : std_ulogic_vector(5 downto 0) := "110001"; -- 1.17: fast interrupt 1
  constant trap_firq2_c : std_ulogic_vector(5 downto 0) := "110010"; -- 1.18: fast interrupt 2
  constant trap_firq3_c : std_ulogic_vector(5 downto 0) := "110011"; -- 1.19: fast interrupt 3
 
  -- CPU Control Exception System -----------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  -- exception source bits --
  constant exception_iaccess_c   : natural := 0; -- instrution access fault
  constant exception_iillegal_c  : natural := 1; -- illegal instrution
  constant exception_ialign_c    : natural := 2; -- instrution address misaligned
  constant exception_m_envcall_c : natural := 3; -- ENV call from m-mode
  constant exception_break_c     : natural := 4; -- breakpoint
  constant exception_salign_c    : natural := 5; -- store address misaligned
  constant exception_lalign_c    : natural := 6; -- load address misaligned
  constant exception_saccess_c   : natural := 7; -- store access fault
  constant exception_laccess_c   : natural := 8; -- load access fault
  --
  constant exception_width_c     : natural := 9; -- length of this list in bits
  -- interrupt source bits --
  constant interrupt_msw_irq_c   : natural := 0; -- machine software interrupt
  constant interrupt_mtime_irq_c : natural := 1; -- machine timer interrupt
  constant interrupt_mext_irq_c  : natural := 2; -- machine external interrupt
  constant interrupt_firq_0_c    : natural := 3; -- fast interrupt channel 0
  constant interrupt_firq_1_c    : natural := 4; -- fast interrupt channel 1
  constant interrupt_firq_2_c    : natural := 5; -- fast interrupt channel 2
  constant interrupt_firq_3_c    : natural := 6; -- fast interrupt channel 3
  --
  constant interrupt_width_c     : natural := 7; -- length of this list in bits
 
  -- CPU Privilege Modes --------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant m_priv_mode_c : std_ulogic_vector(1 downto 0) := "11"; -- machine mode
  constant u_priv_mode_c : std_ulogic_vector(1 downto 0) := "00"; -- user mode
 
  -- Clock Generator -------------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  constant clk_div2_c    : natural := 0;
  constant clk_div4_c    : natural := 1;
  constant clk_div8_c    : natural := 2;
  constant clk_div64_c   : natural := 3;
  constant clk_div128_c  : natural := 4;
  constant clk_div1024_c : natural := 5;
  constant clk_div2048_c : natural := 6;
  constant clk_div4096_c : natural := 7;
 
  -- Component: NEORV32 Processor Top Entity ------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_top
    generic (
      -- General --
      CLOCK_FREQUENCY              : natural := 0;      -- clock frequency of clk_i in Hz
      BOOTLOADER_USE               : boolean := true;   -- implement processor-internal bootloader?
      USER_CODE                    : std_ulogic_vector(31 downto 0) := x"00000000"; -- custom user code
      -- RISC-V CPU Extensions --
      CPU_EXTENSION_RISCV_C        : boolean := false;  -- implement compressed extension?
      CPU_EXTENSION_RISCV_E        : boolean := false;  -- implement embedded RF extension?
      CPU_EXTENSION_RISCV_M        : boolean := false;  -- implement muld/div extension?
      CPU_EXTENSION_RISCV_U        : boolean := false;  -- implement user mode extension?
      CPU_EXTENSION_RISCV_Zicsr    : boolean := true;   -- implement CSR system?
      CPU_EXTENSION_RISCV_Zifencei : boolean := true;   -- implement instruction stream sync.?
      -- Extension Options --
      CSR_COUNTERS_USE             : boolean := true;  -- implement RISC-V perf. counters ([m]instret[h], [m]cycle[h], time[h])?
      FAST_MUL_EN                  : boolean := false; -- use DSPs for M extension's multiplier
      -- Physical Memory Protection (PMP) --
      PMP_USE                      : boolean := false; -- implement PMP?
      PMP_NUM_REGIONS              : natural := 4;     -- number of regions (max 8)
      PMP_GRANULARITY              : natural := 14;    -- minimal region granularity (1=8B, 2=16B, 3=32B, ...) default is 64k
      -- Memory configuration: Instruction memory --
      MEM_ISPACE_BASE              : std_ulogic_vector(31 downto 0) := x"00000000"; -- base address of instruction memory space
      MEM_ISPACE_SIZE              : natural := 16*1024; -- total size of instruction memory space in byte
      MEM_INT_IMEM_USE             : boolean := true;    -- implement processor-internal instruction memory
      MEM_INT_IMEM_SIZE            : natural := 16*1024; -- size of processor-internal instruction memory in bytes
      MEM_INT_IMEM_ROM             : boolean := false;   -- implement processor-internal instruction memory as ROM
      -- Memory configuration: Data memory --
      MEM_DSPACE_BASE              : std_ulogic_vector(31 downto 0) := x"80000000"; -- base address of data memory space
      MEM_DSPACE_SIZE              : natural := 8*1024; -- total size of data memory space in byte
      MEM_INT_DMEM_USE             : boolean := true;   -- implement processor-internal data memory
      MEM_INT_DMEM_SIZE            : natural := 8*1024; -- size of processor-internal data memory in bytes
      -- Memory configuration: External memory interface --
      MEM_EXT_USE                  : boolean := false;  -- implement external memory bus interface?
      MEM_EXT_REG_STAGES           : natural := 2;      -- number of interface register stages (0,1,2)
      MEM_EXT_TIMEOUT              : natural := 15;     -- cycles after which a valid bus access will timeout (>=1)
      -- Processor peripherals --
      IO_GPIO_USE                  : boolean := true;   -- implement general purpose input/output port unit (GPIO)?
      IO_MTIME_USE                 : boolean := true;   -- implement machine system timer (MTIME)?
      IO_UART_USE                  : boolean := true;   -- implement universal asynchronous receiver/transmitter (UART)?
      IO_SPI_USE                   : boolean := true;   -- implement serial peripheral interface (SPI)?
      IO_TWI_USE                   : boolean := true;   -- implement two-wire interface (TWI)?
      IO_PWM_USE                   : boolean := true;   -- implement pulse-width modulation unit (PWM)?
      IO_WDT_USE                   : boolean := true;   -- implement watch dog timer (WDT)?
      IO_TRNG_USE                  : boolean := false;  -- implement true random number generator (TRNG)?
      IO_DEVNULL_USE               : boolean := true    -- implement dummy device (DEVNULL)?
    );
    port (
      -- Global control --
      clk_i      : in  std_ulogic := '0'; -- global clock, rising edge
      rstn_i     : in  std_ulogic := '0'; -- global reset, low-active, async
      -- Wishbone bus interface --
      wb_adr_o   : out std_ulogic_vector(31 downto 0); -- address
      wb_dat_i   : in  std_ulogic_vector(31 downto 0) := (others => '0'); -- read data
      wb_dat_o   : out std_ulogic_vector(31 downto 0); -- write data
      wb_we_o    : out std_ulogic; -- read/write
      wb_sel_o   : out std_ulogic_vector(03 downto 0); -- byte enable
      wb_stb_o   : out std_ulogic; -- strobe
      wb_cyc_o   : out std_ulogic; -- valid cycle
      wb_ack_i   : in  std_ulogic := '0'; -- transfer acknowledge
      wb_err_i   : in  std_ulogic := '0'; -- transfer error
      -- Advanced memory control signals (available if MEM_EXT_USE = true) --
      fence_o    : out std_ulogic; -- indicates an executed FENCE operation
      fencei_o   : out std_ulogic; -- indicates an executed FENCEI operation
      -- GPIO --
      gpio_o     : out std_ulogic_vector(31 downto 0); -- parallel output
      gpio_i     : in  std_ulogic_vector(31 downto 0) := (others => '0'); -- parallel input
      -- UART --
      uart_txd_o : out std_ulogic; -- UART send data
      uart_rxd_i : in  std_ulogic := '0'; -- UART receive data
      -- SPI --
      spi_sck_o  : out std_ulogic; -- SPI serial clock
      spi_sdo_o  : out std_ulogic; -- controller data out, peripheral data in
      spi_sdi_i  : in  std_ulogic := '0'; -- controller data in, peripheral data out
      spi_csn_o  : out std_ulogic_vector(07 downto 0); -- SPI CS
      -- TWI --
      twi_sda_io : inout std_logic := 'H'; -- twi serial data line
      twi_scl_io : inout std_logic := 'H'; -- twi serial clock line
      -- PWM --
      pwm_o      : out std_ulogic_vector(03 downto 0);  -- pwm channels
      -- Interrupts --
      msw_irq_i  : in  std_ulogic := '0'; -- machine software interrupt
      mext_irq_i : in  std_ulogic := '0'  -- machine external interrupt
    );
  end component;
 
  -- Component: CPU Top Entity --------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu
    generic (
      -- General --
      HW_THREAD_ID                 : std_ulogic_vector(31 downto 0):= (others => '0'); -- hardware thread id
      CPU_BOOT_ADDR                : std_ulogic_vector(31 downto 0):= (others => '0'); -- cpu boot address
      -- RISC-V CPU Extensions --
      CPU_EXTENSION_RISCV_C        : boolean := false; -- implement compressed extension?
      CPU_EXTENSION_RISCV_E        : boolean := false; -- implement embedded RF extension?
      CPU_EXTENSION_RISCV_M        : boolean := false; -- implement muld/div extension?
      CPU_EXTENSION_RISCV_U        : boolean := false; -- implement user mode extension?
      CPU_EXTENSION_RISCV_Zicsr    : boolean := true;  -- implement CSR system?
      CPU_EXTENSION_RISCV_Zifencei : boolean := true;  -- implement instruction stream sync.?
      -- Extension Options --
      CSR_COUNTERS_USE             : boolean := true;  -- implement RISC-V perf. counters ([m]instret[h], [m]cycle[h], time[h])?
      FAST_MUL_EN                  : boolean := false; -- use DSPs for M extension's multiplier
      -- Physical Memory Protection (PMP) --
      PMP_USE                      : boolean := false; -- implement PMP?
      PMP_NUM_REGIONS              : natural := 4;     -- number of regions (max 8)
      PMP_GRANULARITY              : natural := 14;    -- minimal region granularity (1=8B, 2=16B, 3=32B, ...) default is 64k
      -- Bus Interface --
      BUS_TIMEOUT                  : natural := 15     -- cycles after which a valid bus access will timeout
    );
    port (
      -- global control --
      clk_i          : in  std_ulogic := '0'; -- global clock, rising edge
      rstn_i         : in  std_ulogic := '0'; -- global reset, low-active, async
      -- instruction bus interface --
      i_bus_addr_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      i_bus_rdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0) := (others => '0'); -- bus read data
      i_bus_wdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      i_bus_ben_o    : out std_ulogic_vector(03 downto 0); -- byte enable
      i_bus_we_o     : out std_ulogic; -- write enable
      i_bus_re_o     : out std_ulogic; -- read enable
      i_bus_cancel_o : out std_ulogic; -- cancel current bus transaction
      i_bus_ack_i    : in  std_ulogic := '0'; -- bus transfer acknowledge
      i_bus_err_i    : in  std_ulogic := '0'; -- bus transfer error
      i_bus_fence_o  : out std_ulogic; -- executed FENCEI operation
      -- data bus interface --
      d_bus_addr_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      d_bus_rdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0) := (others => '0'); -- bus read data
      d_bus_wdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      d_bus_ben_o    : out std_ulogic_vector(03 downto 0); -- byte enable
      d_bus_we_o     : out std_ulogic; -- write enable
      d_bus_re_o     : out std_ulogic; -- read enable
      d_bus_cancel_o : out std_ulogic; -- cancel current bus transaction
      d_bus_ack_i    : in  std_ulogic := '0'; -- bus transfer acknowledge
      d_bus_err_i    : in  std_ulogic := '0'; -- bus transfer error
      d_bus_fence_o  : out std_ulogic; -- executed FENCE operation
      -- system time input from MTIME --
      time_i         : in  std_ulogic_vector(63 downto 0) := (others => '0'); -- current system time
      -- interrupts (risc-v compliant) --
      msw_irq_i      : in  std_ulogic := '0'; -- machine software interrupt
      mext_irq_i     : in  std_ulogic := '0'; -- machine external interrupt
      mtime_irq_i    : in  std_ulogic := '0'; -- machine timer interrupt
      -- fast interrupts (custom) --
      firq_i         : in  std_ulogic_vector(3 downto 0) := (others => '0')
    );
  end component;
 
  -- Component: CPU Control -----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_control
    generic (
      -- General --
      CSR_COUNTERS_USE             : boolean := true;  -- implement RISC-V perf. counters ([m]instret[h], [m]cycle[h], time[h])?
      HW_THREAD_ID                 : std_ulogic_vector(31 downto 0):= x"00000000"; -- hardware thread id
      CPU_BOOT_ADDR                : std_ulogic_vector(31 downto 0):= x"00000000"; -- cpu boot address
      -- RISC-V CPU Extensions --
      CPU_EXTENSION_RISCV_C        : boolean := false; -- implement compressed extension?
      CPU_EXTENSION_RISCV_E        : boolean := false; -- implement embedded RF extension?
      CPU_EXTENSION_RISCV_M        : boolean := false; -- implement muld/div extension?
      CPU_EXTENSION_RISCV_U        : boolean := false; -- implement user mode extension?
      CPU_EXTENSION_RISCV_Zicsr    : boolean := true;  -- implement CSR system?
      CPU_EXTENSION_RISCV_Zifencei : boolean := true;  -- implement instruction stream sync.?
      -- Physical memory protection (PMP) --
      PMP_USE                      : boolean := false; -- implement physical memory protection?
      PMP_NUM_REGIONS              : natural := 4; -- number of regions (1..4)
      PMP_GRANULARITY              : natural := 0  -- granularity (0=none, 1=8B, 2=16B, 3=32B, ...)
    );
    port (
      -- global control --
      clk_i         : in  std_ulogic; -- global clock, rising edge
      rstn_i        : in  std_ulogic; -- global reset, low-active, async
      ctrl_o        : out std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
      -- status input --
      alu_wait_i    : in  std_ulogic; -- wait for ALU
      bus_i_wait_i  : in  std_ulogic; -- wait for bus
      bus_d_wait_i  : in  std_ulogic; -- wait for bus
      -- data input --
      instr_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- instruction
      cmp_i         : in  std_ulogic_vector(1 downto 0); -- comparator status
      alu_add_i     : in  std_ulogic_vector(data_width_c-1 downto 0); -- ALU.add result
      -- data output --
      imm_o         : out std_ulogic_vector(data_width_c-1 downto 0); -- immediate
      fetch_pc_o    : out std_ulogic_vector(data_width_c-1 downto 0); -- PC for instruction fetch
      curr_pc_o     : out std_ulogic_vector(data_width_c-1 downto 0); -- current PC (corresponding to current instruction)
      next_pc_o     : out std_ulogic_vector(data_width_c-1 downto 0); -- next PC (corresponding to current instruction)
      -- csr interface --
      csr_wdata_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- CSR write data
      csr_rdata_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- CSR read data
      -- interrupts (risc-v compliant) --
      msw_irq_i     : in  std_ulogic; -- machine software interrupt
      mext_irq_i    : in  std_ulogic; -- machine external interrupt
      mtime_irq_i   : in  std_ulogic; -- machine timer interrupt
      -- fast interrupts (custom) --
      firq_i        : in  std_ulogic_vector(3 downto 0);
      -- system time input from MTIME --
      time_i        : in  std_ulogic_vector(63 downto 0); -- current system time
      -- physical memory protection --
      pmp_addr_o    : out pmp_addr_if_t; -- addresses
      pmp_ctrl_o    : out pmp_ctrl_if_t; -- configs
      priv_mode_o   : out std_ulogic_vector(1 downto 0); -- current CPU privilege level
      -- bus access exceptions --
      mar_i         : in  std_ulogic_vector(data_width_c-1 downto 0); -- memory address register
      ma_instr_i    : in  std_ulogic; -- misaligned instruction address
      ma_load_i     : in  std_ulogic; -- misaligned load data address
      ma_store_i    : in  std_ulogic; -- misaligned store data address
      be_instr_i    : in  std_ulogic; -- bus error on instruction access
      be_load_i     : in  std_ulogic; -- bus error on load data access
      be_store_i    : in  std_ulogic  -- bus error on store data access
    );
  end component;
 
  -- Component: CPU Register File -----------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_regfile
    generic (
      CPU_EXTENSION_RISCV_E : boolean := false -- implement embedded RF extension?
    );
    port (
      -- global control --
      clk_i  : in  std_ulogic; -- global clock, rising edge
      ctrl_i : in  std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
      -- data input --
      mem_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- memory read data
      alu_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- ALU result
      csr_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- CSR read data
      pc_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- current pc
      -- data output --
      rs1_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- operand 1
      rs2_o  : out std_ulogic_vector(data_width_c-1 downto 0)  -- operand 2
    );
  end component;
 
  -- Component: CPU ALU ---------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_alu
    generic (
      CPU_EXTENSION_RISCV_M : boolean := true -- implement muld/div extension?
    );
    port (
      -- global control --
      clk_i       : in  std_ulogic; -- global clock, rising edge
      rstn_i      : in  std_ulogic; -- global reset, low-active, async
      ctrl_i      : in  std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
      -- data input --
      rs1_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- rf source 1
      rs2_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- rf source 2
      pc2_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- delayed PC
      imm_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- immediate
      csr_i       : in  std_ulogic_vector(data_width_c-1 downto 0); -- csr read data
      -- data output --
      cmp_o       : out std_ulogic_vector(1 downto 0); -- comparator status
      add_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- OPA + OPB
      res_o       : out std_ulogic_vector(data_width_c-1 downto 0); -- ALU result
      -- co-processor interface --
      cp0_start_o : out std_ulogic; -- trigger co-processor 0
      cp0_data_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- co-processor 0 result
      cp0_valid_i : in  std_ulogic; -- co-processor 0 result valid
      cp1_start_o : out std_ulogic; -- trigger co-processor 1
      cp1_data_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- co-processor 1 result
      cp1_valid_i : in  std_ulogic; -- co-processor 1 result valid
      -- status --
      wait_o      : out std_ulogic -- busy due to iterative processing units
    );
  end component;
 
  -- Component: CPU Co-Processor MULDIV -----------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_cp_muldiv
    generic (
      FAST_MUL_EN : boolean := false -- use DSPs for faster multiplication
    );
    port (
      -- global control --
      clk_i   : in  std_ulogic; -- global clock, rising edge
      rstn_i  : in  std_ulogic; -- global reset, low-active, async
      ctrl_i  : in  std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
      -- data input --
      start_i : in  std_ulogic; -- trigger operation
      rs1_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- rf source 1
      rs2_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- rf source 2
      -- result and status --
      res_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- operation result
      valid_o : out std_ulogic -- data output valid
    );
  end component;
 
  -- Component: CPU Bus Interface -----------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_bus
    generic (
      CPU_EXTENSION_RISCV_C : boolean := true; -- implement compressed extension?
      BUS_TIMEOUT           : natural := 15;   -- cycles after which a valid bus access will timeout
      -- Physical memory protection (PMP) --
      PMP_USE               : boolean := false; -- implement physical memory protection?
      PMP_NUM_REGIONS       : natural := 4; -- number of regions (1..4)
      PMP_GRANULARITY       : natural := 0  -- granularity (1=8B, 2=16B, 3=32B, ...)
    );
    port (
      -- global control --
      clk_i          : in  std_ulogic; -- global clock, rising edge
      rstn_i         : in  std_ulogic; -- global reset, low-active, async
      ctrl_i         : in  std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
      -- cpu instruction fetch interface --
      fetch_pc_i     : in  std_ulogic_vector(data_width_c-1 downto 0); -- PC for instruction fetch
      instr_o        : out std_ulogic_vector(data_width_c-1 downto 0); -- instruction
      i_wait_o       : out std_ulogic; -- wait for fetch to complete
      --
      ma_instr_o     : out std_ulogic; -- misaligned instruction address
      be_instr_o     : out std_ulogic; -- bus error on instruction access
      -- cpu data access interface --
      addr_i         : in  std_ulogic_vector(data_width_c-1 downto 0); -- ALU result -> access address
      wdata_i        : in  std_ulogic_vector(data_width_c-1 downto 0); -- write data
      rdata_o        : out std_ulogic_vector(data_width_c-1 downto 0); -- read data
      mar_o          : out std_ulogic_vector(data_width_c-1 downto 0); -- current memory address register
      d_wait_o       : out std_ulogic; -- wait for access to complete
      --
      ma_load_o      : out std_ulogic; -- misaligned load data address
      ma_store_o     : out std_ulogic; -- misaligned store data address
      be_load_o      : out std_ulogic; -- bus error on load data access
      be_store_o     : out std_ulogic; -- bus error on store data access
      -- physical memory protection --
      pmp_addr_i     : in  pmp_addr_if_t; -- addresses
      pmp_ctrl_i     : in  pmp_ctrl_if_t; -- configs
      priv_mode_i    : in  std_ulogic_vector(1 downto 0); -- current CPU privilege level
      -- instruction bus --
      i_bus_addr_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      i_bus_rdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus read data
      i_bus_wdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      i_bus_ben_o    : out std_ulogic_vector(03 downto 0); -- byte enable
      i_bus_we_o     : out std_ulogic; -- write enable
      i_bus_re_o     : out std_ulogic; -- read enable
      i_bus_cancel_o : out std_ulogic; -- cancel current bus transaction
      i_bus_ack_i    : in  std_ulogic; -- bus transfer acknowledge
      i_bus_err_i    : in  std_ulogic; -- bus transfer error
      i_bus_fence_o  : out std_ulogic; -- fence operation
      -- data bus --
      d_bus_addr_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      d_bus_rdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus read data
      d_bus_wdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      d_bus_ben_o    : out std_ulogic_vector(03 downto 0); -- byte enable
      d_bus_we_o     : out std_ulogic; -- write enable
      d_bus_re_o     : out std_ulogic; -- read enable
      d_bus_cancel_o : out std_ulogic; -- cancel current bus transaction
      d_bus_ack_i    : in  std_ulogic; -- bus transfer acknowledge
      d_bus_err_i    : in  std_ulogic; -- bus transfer error
      d_bus_fence_o  : out std_ulogic  -- fence operation
    );
  end component;
 
  -- Component: CPU Bus Switch --------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_busswitch
    generic (
      PORT_CA_READ_ONLY : boolean := false; -- set if controller port A is read-only
      PORT_CB_READ_ONLY : boolean := false  -- set if controller port B is read-only
    );
    port (
      -- global control --
      clk_i           : in  std_ulogic; -- global clock, rising edge
      rstn_i          : in  std_ulogic; -- global reset, low-active, async
      -- controller interface a --
      ca_bus_addr_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      ca_bus_rdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus read data
      ca_bus_wdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      ca_bus_ben_i    : in  std_ulogic_vector(03 downto 0); -- byte enable
      ca_bus_we_i     : in  std_ulogic; -- write enable
      ca_bus_re_i     : in  std_ulogic; -- read enable
      ca_bus_cancel_i : in  std_ulogic; -- cancel current bus transaction
      ca_bus_ack_o    : out std_ulogic; -- bus transfer acknowledge
      ca_bus_err_o    : out std_ulogic; -- bus transfer error
      -- controller interface b --
      cb_bus_addr_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      cb_bus_rdata_o  : out std_ulogic_vector(data_width_c-1 downto 0); -- bus read data
      cb_bus_wdata_i  : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      cb_bus_ben_i    : in  std_ulogic_vector(03 downto 0); -- byte enable
      cb_bus_we_i     : in  std_ulogic; -- write enable
      cb_bus_re_i     : in  std_ulogic; -- read enable
      cb_bus_cancel_i : in  std_ulogic; -- cancel current bus transaction
      cb_bus_ack_o    : out std_ulogic; -- bus transfer acknowledge
      cb_bus_err_o    : out std_ulogic; -- bus transfer error
      -- peripheral bus --
      p_bus_addr_o    : out std_ulogic_vector(data_width_c-1 downto 0); -- bus access address
      p_bus_rdata_i   : in  std_ulogic_vector(data_width_c-1 downto 0); -- bus read data
      p_bus_wdata_o   : out std_ulogic_vector(data_width_c-1 downto 0); -- bus write data
      p_bus_ben_o     : out std_ulogic_vector(03 downto 0); -- byte enable
      p_bus_we_o      : out std_ulogic; -- write enable
      p_bus_re_o      : out std_ulogic; -- read enable
      p_bus_cancel_o  : out std_ulogic; -- cancel current bus transaction
      p_bus_ack_i     : in  std_ulogic; -- bus transfer acknowledge
      p_bus_err_i     : in  std_ulogic  -- bus transfer error
    );
  end component;
 
  -- Component: CPU Compressed Instructions Decompressor ------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_cpu_decompressor
    port (
      -- instruction input --
      ci_instr16_i : in  std_ulogic_vector(15 downto 0); -- compressed instruction input
      -- instruction output --
      ci_illegal_o : out std_ulogic; -- is an illegal compressed instruction
      ci_instr32_o : out std_ulogic_vector(31 downto 0)  -- 32-bit decompressed instruction
    );
  end component;
 
  -- Component: Processor-internal instruction memory (IMEM) --------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_imem
    generic (
      IMEM_BASE      : std_ulogic_vector(31 downto 0) := x"00000000"; -- memory base address
      IMEM_SIZE      : natural := 4*1024; -- processor-internal instruction memory size in bytes
      IMEM_AS_ROM    : boolean := false;  -- implement IMEM as read-only memory?
      BOOTLOADER_USE : boolean := true    -- implement and use bootloader?
    );
    port (
      clk_i  : in  std_ulogic; -- global clock line
      rden_i : in  std_ulogic; -- read enable
      wren_i : in  std_ulogic; -- write enable
      ben_i  : in  std_ulogic_vector(03 downto 0); -- byte write enable
      upen_i : in  std_ulogic; -- update enable
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      data_i : in  std_ulogic_vector(31 downto 0); -- data in
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic -- transfer acknowledge
    );
  end component;
 
  -- Component: Processor-internal data memory (DMEM) ---------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_dmem
    generic (
      DMEM_BASE : std_ulogic_vector(31 downto 0) := x"80000000"; -- memory base address
      DMEM_SIZE : natural := 4*1024  -- processor-internal instruction memory size in bytes
    );
    port (
      clk_i  : in  std_ulogic; -- global clock line
      rden_i : in  std_ulogic; -- read enable
      wren_i : in  std_ulogic; -- write enable
      ben_i  : in  std_ulogic_vector(03 downto 0); -- byte write enable
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      data_i : in  std_ulogic_vector(31 downto 0); -- data in
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic -- transfer acknowledge
    );
  end component;
 
  -- Component: Processor-internal bootloader ROM (BOOTROM) ---------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_boot_rom
    port (
      clk_i  : in  std_ulogic; -- global clock line
      rden_i : in  std_ulogic; -- read enable
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic -- transfer acknowledge
    );
  end component;
 
  -- Component: Machine System Timer (mtime) ------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_mtime
    port (
      -- host access --
      clk_i     : in  std_ulogic; -- global clock line
      rstn_i    : in  std_ulogic := '0'; -- global reset, low-active, async
      addr_i    : in  std_ulogic_vector(31 downto 0); -- address
      rden_i    : in  std_ulogic; -- read enable
      wren_i    : in  std_ulogic; -- write enable
      data_i    : in  std_ulogic_vector(31 downto 0); -- data in
      data_o    : out std_ulogic_vector(31 downto 0); -- data out
      ack_o     : out std_ulogic; -- transfer acknowledge
      -- time output for CPU --
      time_o    : out std_ulogic_vector(63 downto 0); -- current system time
      -- interrupt --
      irq_o     : out std_ulogic  -- interrupt request
    );
  end component;
 
  -- Component: General Purpose Input/Output Port (GPIO) ------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_gpio
    port (
      -- host access --
      clk_i  : in  std_ulogic; -- global clock line
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      rden_i : in  std_ulogic; -- read enable
      wren_i : in  std_ulogic; -- write enable
      data_i : in  std_ulogic_vector(31 downto 0); -- data in
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic; -- transfer acknowledge
      -- parallel io --
      gpio_o : out std_ulogic_vector(31 downto 0);
      gpio_i : in  std_ulogic_vector(31 downto 0);
      -- interrupt --
      irq_o  : out std_ulogic
    );
  end component;
 
  -- Component: Watchdog Timer (WDT) --------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_wdt
    port (
      -- host access --
      clk_i       : in  std_ulogic; -- global clock line
      rstn_i      : in  std_ulogic; -- global reset line, low-active
      rden_i      : in  std_ulogic; -- read enable
      wren_i      : in  std_ulogic; -- write enable
      addr_i      : in  std_ulogic_vector(31 downto 0); -- address
      data_i      : in  std_ulogic_vector(31 downto 0); -- data in
      data_o      : out std_ulogic_vector(31 downto 0); -- data out
      ack_o       : out std_ulogic; -- transfer acknowledge
      -- clock generator --
      clkgen_en_o : out std_ulogic; -- enable clock generator
      clkgen_i    : in  std_ulogic_vector(07 downto 0);
      -- timeout event --
      irq_o       : out std_ulogic; -- timeout IRQ
      rstn_o      : out std_ulogic  -- timeout reset, low_active, use it as async!
    );
  end component;
 
  -- Component: Universal Asynchronous Receiver and Transmitter (UART) ----------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_uart
    port (
      -- host access --
      clk_i       : in  std_ulogic; -- global clock line
      addr_i      : in  std_ulogic_vector(31 downto 0); -- address
      rden_i      : in  std_ulogic; -- read enable
      wren_i      : in  std_ulogic; -- write enable
      data_i      : in  std_ulogic_vector(31 downto 0); -- data in
      data_o      : out std_ulogic_vector(31 downto 0); -- data out
      ack_o       : out std_ulogic; -- transfer acknowledge
      -- clock generator --
      clkgen_en_o : out std_ulogic; -- enable clock generator
      clkgen_i    : in  std_ulogic_vector(07 downto 0);
      -- com lines --
      uart_txd_o  : out std_ulogic;
      uart_rxd_i  : in  std_ulogic;
      -- interrupts --
      uart_irq_o  : out std_ulogic  -- uart rx/tx interrupt
    );
  end component;
 
  -- Component: Serial Peripheral Interface (SPI) -------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_spi
    port (
      -- host access --
      clk_i       : in  std_ulogic; -- global clock line
      addr_i      : in  std_ulogic_vector(31 downto 0); -- address
      rden_i      : in  std_ulogic; -- read enable
      wren_i      : in  std_ulogic; -- write enable
      data_i      : in  std_ulogic_vector(31 downto 0); -- data in
      data_o      : out std_ulogic_vector(31 downto 0); -- data out
      ack_o       : out std_ulogic; -- transfer acknowledge
      -- clock generator --
      clkgen_en_o : out std_ulogic; -- enable clock generator
      clkgen_i    : in  std_ulogic_vector(07 downto 0);
      -- com lines --
      spi_sck_o   : out std_ulogic; -- SPI serial clock
      spi_sdo_o   : out std_ulogic; -- controller data out, peripheral data in
      spi_sdi_i   : in  std_ulogic; -- controller data in, peripheral data out
      spi_csn_o   : out std_ulogic_vector(07 downto 0); -- SPI CS
      -- interrupt --
      spi_irq_o   : out std_ulogic -- transmission done interrupt
    );
  end component;
 
  -- Component: Two-Wire Interface (TWI) ----------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_twi
    port (
      -- host access --
      clk_i       : in  std_ulogic; -- global clock line
      addr_i      : in  std_ulogic_vector(31 downto 0); -- address
      rden_i      : in  std_ulogic; -- read enable
      wren_i      : in  std_ulogic; -- write enable
      data_i      : in  std_ulogic_vector(31 downto 0); -- data in
      data_o      : out std_ulogic_vector(31 downto 0); -- data out
      ack_o       : out std_ulogic; -- transfer acknowledge
      -- clock generator --
      clkgen_en_o : out std_ulogic; -- enable clock generator
      clkgen_i    : in  std_ulogic_vector(07 downto 0);
      -- com lines --
      twi_sda_io  : inout std_logic; -- serial data line
      twi_scl_io  : inout std_logic; -- serial clock line
      -- interrupt --
      twi_irq_o   : out std_ulogic -- transfer done IRQ
    );
  end component;
 
  -- Component: Pulse-Width Modulation Controller (PWM) -------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_pwm
    port (
      -- host access --
      clk_i       : in  std_ulogic; -- global clock line
      addr_i      : in  std_ulogic_vector(31 downto 0); -- address
      rden_i      : in  std_ulogic; -- read enable
      wren_i      : in  std_ulogic; -- write enable
      data_i      : in  std_ulogic_vector(31 downto 0); -- data in
      data_o      : out std_ulogic_vector(31 downto 0); -- data out
      ack_o       : out std_ulogic; -- transfer acknowledge
      -- clock generator --
      clkgen_en_o : out std_ulogic; -- enable clock generator
      clkgen_i    : in  std_ulogic_vector(07 downto 0);
      -- pwm output channels --
      pwm_o       : out std_ulogic_vector(03 downto 0)
    );
  end component;
 
  -- Component: True Random Number Generator (TRNG) -----------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_trng
    port (
      -- host access --
      clk_i  : in  std_ulogic; -- global clock line
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      rden_i : in  std_ulogic; -- read enable
      wren_i : in  std_ulogic; -- write enable
      data_i : in  std_ulogic_vector(31 downto 0); -- data in
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic  -- transfer acknowledge
    );
  end component;
 
  -- Component: Wishbone Bus Gateway (WISHBONE) ---------------------------------------------
  -- -------------------------------------------------------------------------------------------
  component neorv32_wishbone
    generic (
      INTERFACE_REG_STAGES : natural := 2; -- number of interface register stages (0,1,2)
      -- Memory configuration: Instruction memory --
      MEM_ISPACE_BASE      : std_ulogic_vector(31 downto 0) := x"00000000"; -- base address of instruction memory space
      MEM_ISPACE_SIZE      : natural := 8*1024; -- total size of instruction memory space in byte
      MEM_INT_IMEM_USE     : boolean := true;   -- implement processor-internal instruction memory
      MEM_INT_IMEM_SIZE    : natural := 8*1024; -- size of processor-internal instruction memory in bytes
      -- Memory configuration: Data memory --
      MEM_DSPACE_BASE      : std_ulogic_vector(31 downto 0) := x"80000000"; -- base address of data memory space
      MEM_DSPACE_SIZE      : natural := 4*1024; -- total size of data memory space in byte
      MEM_INT_DMEM_USE     : boolean := true;   -- implement processor-internal data memory
      MEM_INT_DMEM_SIZE    : natural := 4*1024  -- size of processor-internal data memory in bytes
    );
    port (
      -- global control --
      clk_i    : in  std_ulogic; -- global clock line
      rstn_i   : in  std_ulogic; -- global reset line, low-active
      -- host access --
      addr_i   : in  std_ulogic_vector(31 downto 0); -- address
      rden_i   : in  std_ulogic; -- read enable
      wren_i   : in  std_ulogic; -- write enable
      ben_i    : in  std_ulogic_vector(03 downto 0); -- byte write enable
      data_i   : in  std_ulogic_vector(31 downto 0); -- data in
      data_o   : out std_ulogic_vector(31 downto 0); -- data out
      cancel_i : in  std_ulogic; -- cancel current bus transaction
      ack_o    : out std_ulogic; -- transfer acknowledge
      err_o    : out std_ulogic; -- transfer error
      -- wishbone interface --
      wb_adr_o : out std_ulogic_vector(31 downto 0); -- address
      wb_dat_i : in  std_ulogic_vector(31 downto 0); -- read data
      wb_dat_o : out std_ulogic_vector(31 downto 0); -- write data
      wb_we_o  : out std_ulogic; -- read/write
      wb_sel_o : out std_ulogic_vector(03 downto 0); -- byte enable
      wb_stb_o : out std_ulogic; -- strobe
      wb_cyc_o : out std_ulogic; -- valid cycle
      wb_ack_i : in  std_ulogic; -- transfer acknowledge
      wb_err_i : in  std_ulogic  -- transfer error
    );
  end component;
 
  ---- Component: Dummy Device with SIM Output (DEVNULL) -------------------------------------
  ---- -------------------------------------------------------------------------------------------
  component neorv32_devnull
    port (
      -- host access --
      clk_i  : in  std_ulogic; -- global clock line
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      rden_i : in  std_ulogic; -- read enable
      wren_i : in  std_ulogic; -- write enable
      data_i : in  std_ulogic_vector(31 downto 0); -- data in
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic  -- transfer acknowledge
    );
  end component;
 
  ---- Component: System Configuration Information Memory (SYSINFO) ---------------------------
  ---- -------------------------------------------------------------------------------------------
  component neorv32_sysinfo
    generic (
      -- General --
      CLOCK_FREQUENCY   : natural := 0;      -- clock frequency of clk_i in Hz
      BOOTLOADER_USE    : boolean := true;   -- implement processor-internal bootloader?
      USER_CODE         : std_ulogic_vector(31 downto 0) := x"00000000"; -- custom user code
      -- Memory configuration: Instruction memory --
      MEM_ISPACE_BASE   : std_ulogic_vector(31 downto 0) := x"00000000"; -- base address of instruction memory space
      MEM_ISPACE_SIZE   : natural := 8*1024; -- total size of instruction memory space in byte
      MEM_INT_IMEM_USE  : boolean := true;   -- implement processor-internal instruction memory
      MEM_INT_IMEM_SIZE : natural := 8*1024; -- size of processor-internal instruction memory in bytes
      MEM_INT_IMEM_ROM  : boolean := false;  -- implement processor-internal instruction memory as ROM
      -- Memory configuration: Data memory --
      MEM_DSPACE_BASE   : std_ulogic_vector(31 downto 0) := x"80000000"; -- base address of data memory space
      MEM_DSPACE_SIZE   : natural := 4*1024; -- total size of data memory space in byte
      MEM_INT_DMEM_USE  : boolean := true;   -- implement processor-internal data memory
      MEM_INT_DMEM_SIZE : natural := 4*1024; -- size of processor-internal data memory in bytes
      -- Memory configuration: External memory interface --
      MEM_EXT_USE       : boolean := false;  -- implement external memory bus interface?
      -- Processor peripherals --
      IO_GPIO_USE       : boolean := true;   -- implement general purpose input/output port unit (GPIO)?
      IO_MTIME_USE      : boolean := true;   -- implement machine system timer (MTIME)?
      IO_UART_USE       : boolean := true;   -- implement universal asynchronous receiver/transmitter (UART)?
      IO_SPI_USE        : boolean := true;   -- implement serial peripheral interface (SPI)?
      IO_TWI_USE        : boolean := true;   -- implement two-wire interface (TWI)?
      IO_PWM_USE        : boolean := true;   -- implement pulse-width modulation unit (PWM)?
      IO_WDT_USE        : boolean := true;   -- implement watch dog timer (WDT)?
      IO_TRNG_USE       : boolean := true;   -- implement true random number generator (TRNG)?
      IO_DEVNULL_USE    : boolean := true    -- implement dummy device (DEVNULL)?
    );
    port (
      -- host access --
      clk_i  : in  std_ulogic; -- global clock line
      addr_i : in  std_ulogic_vector(31 downto 0); -- address
      rden_i : in  std_ulogic; -- read enable
      data_o : out std_ulogic_vector(31 downto 0); -- data out
      ack_o  : out std_ulogic  -- transfer acknowledge
    );
  end component;
 
end neorv32_package;
 
package body neorv32_package is
 
  -- Function: Minimal required bit width ---------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function index_size_f(input : natural) return natural is
  begin
    for i in 0 to natural'high loop
      if (2**i >= input) then
        return i;
      end if;
    end loop; -- i
    return 0;
  end function index_size_f;
 
  -- Function: Conditional select natural ---------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function cond_sel_natural_f(cond : boolean; val_t : natural; val_f : natural) return natural is
  begin
    if (cond = true) then
      return val_t;
    else
      return val_f;
    end if;
  end function cond_sel_natural_f;
 
  -- Function: Conditional select std_ulogic_vector -----------------------------------------
  -- -------------------------------------------------------------------------------------------
  function cond_sel_stdulogicvector_f(cond : boolean; val_t : std_ulogic_vector; val_f : std_ulogic_vector) return std_ulogic_vector is
  begin
    if (cond = true) then
      return val_t;
    else
      return val_f;
    end if;
  end function cond_sel_stdulogicvector_f;
 
  -- Function: Convert BOOL to STD_ULOGIC ---------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function bool_to_ulogic_f(cond : boolean) return std_ulogic is
  begin
    if (cond = true) then
      return '1';
    else
      return '0';
    end if;
  end function bool_to_ulogic_f;
 
  -- Function: OR all bits ------------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function or_all_f(a : std_ulogic_vector) return std_ulogic is
    variable tmp_v : std_ulogic;
  begin
    tmp_v := a(a'low);
    if (a'low < a'high) then -- not null range?
      for i in a'low+1 to a'high loop
        tmp_v := tmp_v or a(i);
      end loop; -- i
    end if;
    return tmp_v;
  end function or_all_f;
 
  -- Function: AND all bits -----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function and_all_f(a : std_ulogic_vector) return std_ulogic is
    variable tmp_v : std_ulogic;
  begin
    tmp_v := a(a'low);
    if (a'low < a'high) then -- not null range?
      for i in a'low+1 to a'high loop
        tmp_v := tmp_v and a(i);
      end loop; -- i
    end if;
    return tmp_v;
  end function and_all_f;
 
  -- Function: XOR all bits -----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function xor_all_f(a : std_ulogic_vector) return std_ulogic is
    variable tmp_v : std_ulogic;
  begin
    tmp_v := a(a'low);
    if (a'low < a'high) then -- not null range?
      for i in a'low+1 to a'high loop
        tmp_v := tmp_v xor a(i);
      end loop; -- i
    end if;
    return tmp_v;
  end function xor_all_f;
 
  -- Function: XNOR all bits ----------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function xnor_all_f(a : std_ulogic_vector) return std_ulogic is
    variable tmp_v : std_ulogic;
  begin
    tmp_v := a(a'low);
    if (a'low < a'high) then -- not null range?
      for i in a'low+1 to a'high loop
        tmp_v := tmp_v xnor a(i);
      end loop; -- i
    end if;
    return tmp_v;
  end function xnor_all_f;
 
  -- Function: Convert to hex char ----------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  function to_hexchar_f(input : std_ulogic_vector(3 downto 0)) return character is
    variable output_v : character;
  begin
    case input is
      when x"0"   => output_v := '0';
      when x"1"   => output_v := '1';
      when x"2"   => output_v := '2';
      when x"3"   => output_v := '3';
      when x"4"   => output_v := '4';
      when x"5"   => output_v := '5';
      when x"6"   => output_v := '6';
      when x"7"   => output_v := '7';
      when x"8"   => output_v := '8';
      when x"9"   => output_v := '9';
      when x"a"   => output_v := 'a';
      when x"b"   => output_v := 'b';
      when x"c"   => output_v := 'c';
      when x"d"   => output_v := 'd';
      when x"e"   => output_v := 'e';
      when x"f"   => output_v := 'f';
      when others => output_v := '?';
    end case;
    return output_v;
  end function to_hexchar_f;
 
end neorv32_package;
 

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