-- ================================================================================ --
-- NEORV32 SoC - Processor Top Entity                                               --
-- -------------------------------------------------------------------------------- --
-- HQ:         https://github.com/stnolting/neorv32                                 --
-- Data Sheet: https://stnolting.github.io/neorv32                                  --
-- User Guide: https://stnolting.github.io/neorv32/ug                               --
-- -------------------------------------------------------------------------------- --
-- The NEORV32 RISC-V Processor - https://github.com/stnolting/neorv32              --
-- Copyright (c) NEORV32 contributors.                                              --
-- Copyright (c) 2020 - 2026 Stephan Nolting. All rights reserved.                  --
-- Licensed under the BSD-3-Clause license, see LICENSE for details.                --
-- SPDX-License-Identifier: BSD-3-Clause                                            --
-- ================================================================================ --

library ieee;
use ieee.std_logic_1164.all;

library neorv32;
use neorv32.neorv32_package.all;

entity neorv32_top is
  generic (
    -- General --
    CLOCK_FREQUENCY     : natural                        := 0;             -- clock frequency of clk_i in Hz
    TRACE_PORT_EN       : boolean                        := false;         -- enable CPU execution trace port
    DUAL_CORE_EN        : boolean                        := false;         -- enable dual-core homogeneous SMP

    -- Boot Configuration --
    BOOT_MODE_SELECT    : natural range 0 to 2           := 0;             -- boot configuration select (default = 0 = bootloader)
    BOOT_ADDR_CUSTOM    : std_ulogic_vector(31 downto 0) := x"00000000";   -- custom CPU boot address (if boot_config = 1)

    -- On-Chip Debugger (OCD) --
    OCD_EN              : boolean                        := false;         -- implement on-chip debugger
    OCD_NUM_HW_TRIGGERS : natural range 0 to 16          := 0;             -- number of hardware break-/watchpoints
    OCD_AUTHENTICATION  : boolean                        := false;         -- implement on-chip debugger authentication
    OCD_JEDEC_ID        : std_ulogic_vector(10 downto 0) := "00000000000"; -- JEDEC ID: continuation codes + vendor ID

    -- RISC-V CPU Extensions --
    RISCV_ISA_C         : boolean                        := false;         -- compressed extension
    RISCV_ISA_E         : boolean                        := false;         -- embedded RF extension
    RISCV_ISA_M         : boolean                        := false;         -- mul/div extension
    RISCV_ISA_U         : boolean                        := false;         -- user mode extension
    RISCV_ISA_Zaamo     : boolean                        := false;         -- atomic read-modify-write operations extension
    RISCV_ISA_Zalrsc    : boolean                        := false;         -- atomic reservation-set operations extension
    RISCV_ISA_Zba       : boolean                        := false;         -- shifted-add bit-manipulation extension
    RISCV_ISA_Zbb       : boolean                        := false;         -- basic bit-manipulation extension
    RISCV_ISA_Zbc       : boolean                        := false;         -- carry-less multiplication instructions
    RISCV_ISA_Zbkb      : boolean                        := false;         -- bit-manipulation instructions for cryptography
    RISCV_ISA_Zbkc      : boolean                        := false;         -- carry-less multiplication instructions
    RISCV_ISA_Zbkx      : boolean                        := false;         -- cryptography crossbar permutation extension
    RISCV_ISA_Zbs       : boolean                        := false;         -- single-bit bit-manipulation extension
    RISCV_ISA_Zcb       : boolean                        := false;         -- additional code size reduction instructions
    RISCV_ISA_Zcmop     : boolean                        := false;         -- compressed may-be-operations
    RISCV_ISA_Zfinx     : boolean                        := false;         -- 32-bit floating-point extension
    RISCV_ISA_Zibi      : boolean                        := false;         -- branch with immediate
    RISCV_ISA_Zicntr    : boolean                        := false;         -- base counters
    RISCV_ISA_Zicond    : boolean                        := false;         -- integer conditional operations
    RISCV_ISA_Zihpm     : boolean                        := false;         -- hardware performance monitors
    RISCV_ISA_Zimop     : boolean                        := false;         -- may-be-operations
    RISCV_ISA_Zknd      : boolean                        := false;         -- cryptography NIST AES decryption extension
    RISCV_ISA_Zkne      : boolean                        := false;         -- cryptography NIST AES encryption extension
    RISCV_ISA_Zknh      : boolean                        := false;         -- cryptography NIST hash extension
    RISCV_ISA_Zksed     : boolean                        := false;         -- ShangMi block cipher extension
    RISCV_ISA_Zksh      : boolean                        := false;         -- ShangMi hash extension
    RISCV_ISA_Zmmul     : boolean                        := false;         -- multiply-only M sub-extension
    RISCV_ISA_Smcntrpmf : boolean                        := false;         -- counter privilege-mode filtering
    RISCV_ISA_Xcfu      : boolean                        := false;         -- custom (instr.) functions unit

    -- Tuning Options --
    CPU_CONSTT_BR_EN    : boolean                        := false;         -- enable constant-time branches
    CPU_FAST_MUL_EN     : boolean                        := false;         -- use DSPs for M extension's multiplier
    CPU_FAST_SHIFT_EN   : boolean                        := false;         -- use barrel shifter for shift operations
    CPU_RF_ARCH_SEL     : natural range 0 to 3           := 0;             -- register file implementation style select

    -- Physical Memory Protection (PMP) --
    PMP_NUM_REGIONS     : natural range 0 to 16          := 0;             -- number of regions
    PMP_MIN_GRANULARITY : natural                        := 4;             -- minimal region granularity in bytes, has to be a power of 2, min 4 bytes
    PMP_TOR_MODE_EN     : boolean                        := false;         -- implement TOR mode
    PMP_NAP_MODE_EN     : boolean                        := false;         -- implement NAPOT/NA4 modes

    -- Hardware Performance Monitors (HPM) --
    HPM_NUM_CNTS        : natural range 0 to 29          := 0;             -- number of implemented HPM counters
    HPM_CNT_WIDTH       : natural range 0 to 64          := 64;            -- total size of HPM counters

    -- Internal Instruction memory (IMEM) --
    IMEM_EN             : boolean                        := false;         -- implement processor-internal instruction memory
    IMEM_BASE           : std_ulogic_vector(31 downto 0) := x"00000000";   -- base address of processor-internal instruction memory (naturally aligned)
    IMEM_SIZE           : natural                        := 16*1024;       -- size of processor-internal instruction memory in bytes (use a power of 2)
    IMEM_OUTREG_EN      : boolean                        := false;         -- enable IMEM output register stage (for improved mapping/timing)

    -- Internal Data memory (DMEM) --
    DMEM_EN             : boolean                        := false;         -- implement processor-internal data memory
    DMEM_BASE           : std_ulogic_vector(31 downto 0) := x"80000000";   -- base address of processor-internal data memory (naturally aligned)
    DMEM_SIZE           : natural                        := 8*1024;        -- size of processor-internal data memory in bytes (use a power of 2)
    DMEM_OUTREG_EN      : boolean                        := false;         -- enable DMEM output register stage (for improved mapping/timing)

    -- CPU Caches --
    ICACHE_EN           : boolean                        := false;         -- implement instruction cache (i-cache)
    ICACHE_NUM_BLOCKS   : natural range 1 to 4096        := 4;             -- i-cache: number of blocks, has to be a power of 2
    DCACHE_EN           : boolean                        := false;         -- implement data cache (d-cache)
    DCACHE_NUM_BLOCKS   : natural range 1 to 4096        := 4;             -- d-cache: number of blocks, has to be a power of 2
    CACHE_BLOCK_SIZE    : natural range 4 to 1024        := 64;            -- i-cache/d-cache: block size in bytes, has to be a power of 2
    CACHE_BURSTS_EN     : boolean                        := true;          -- i-cache/d-cache: enable issuing of burst transfer for cache update
    CACHE_UC_BASE       : std_ulogic_vector(31 downto 0) := x"F0000000";   -- base address of uncached address space (has to be 256MB-aligned)

    -- Serial Memory Controller (SMC) --
    SMC_EN              : boolean                        := false;         -- implement serial memory controller
    SMC_BASE            : std_ulogic_vector(31 downto 0) := x"E0000000";   -- serial memory base address (256MB-aligned)

    -- External Bus Interface (XBUS) --
    XBUS_EN             : boolean                        := false;         -- implement external bus interface
    XBUS_TIMEOUT        : natural                        := 2048;          -- cycles after a pending bus access auto-terminates (0 = disabled)
    XBUS_REGSTAGE_EN    : boolean                        := false;         -- add XBUS register stage

    -- General-Purpose Input/Output Controller (GPIO) --
    IO_GPIO_NUM         : natural range 0 to 32          := 0;             -- number of GPIO input/output pairs
    IO_GPIO_DIR_EN      : boolean                        := false;         -- enable GPIO direction control port

    -- RISC-V Core-Local Interruptor (CLINT) --
    IO_CLINT_EN         : boolean                        := false;         -- implement core local interruptor (CLINT)

    -- Universal Asynchronous Receiver/Transmitter (UART0/UART1) --
    IO_UART0_EN         : boolean                        := false;         -- implement primary universal asynchronous receiver/transmitter (UART0)
    IO_UART0_RX_FIFO    : natural range 1 to 2**15       := 1;             -- RX FIFO depth, has to be a power of two
    IO_UART0_TX_FIFO    : natural range 1 to 2**15       := 1;             -- TX FIFO depth, has to be a power of two
    IO_UART1_EN         : boolean                        := false;         -- implement secondary universal asynchronous receiver/transmitter (UART1)
    IO_UART1_RX_FIFO    : natural range 1 to 2**15       := 1;             -- RX FIFO depth, has to be a power of two
    IO_UART1_TX_FIFO    : natural range 1 to 2**15       := 1;             -- TX FIFO depth, has to be a power of two

    -- Serial Peripheral Interface (SPI Host, SDI Device) --
    IO_SPI_EN           : boolean                        := false;         -- implement serial peripheral interface (SPI)
    IO_SPI_FIFO         : natural range 1 to 2**15       := 1;             -- RTX FIFO depth, has to be a power of two
    IO_SDI_EN           : boolean                        := false;         -- implement serial data interface (SDI)
    IO_SDI_FIFO         : natural range 1 to 2**15       := 1;             -- RTX FIFO depth, has to be zero or a power of two

    -- Two-Wire Interface (TWI Host, TWD Device) --
    IO_TWI_EN           : boolean                        := false;         -- implement two-wire interface (TWI)
    IO_TWI_FIFO         : natural range 1 to 2**15       := 1;             -- RTX FIFO depth, has to be zero or a power of two
    IO_TWD_EN           : boolean                        := false;         -- implement two-wire device (TWD)
    IO_TWD_RX_FIFO      : natural range 1 to 2**15       := 1;             -- RX FIFO depth, has to be zero or a power of two
    IO_TWD_TX_FIFO      : natural range 1 to 2**15       := 1;             -- TX FIFO depth, has to be zero or a power of two

    -- Pulse-Width Modulation Controller (PWM) --
    IO_PWM_NUM          : natural range 0 to 32          := 0;             -- number of PWM channels to implement

    -- Watchdog Timer (WDT) --
    IO_WDT_EN           : boolean                        := false;         -- implement watch dog timer (WDT)

    -- True-Random Number Generator (TRNG) --
    IO_TRNG_EN          : boolean                        := false;         -- implement true random number generator (TRNG)
    IO_TRNG_FIFO        : natural range 1 to 2**15       := 1;             -- data FIFO depth, has to be a power of two
    IO_TRNG_NUM_RO      : natural range 1 to 255         := 3;             -- total number of ring-oscillators
    IO_TRNG_NUM_INV     : natural range 3 to 4095        := 5;             -- number of inverters in first ring-oscillator; has to be odd
    IO_TRNG_NUM_RBIT    : natural range 8 to 4096        := 64;            -- number of raw bits to process for one output byte; has to be power of two

    -- Custom Functions Subsystem (CFS) --
    IO_CFS_EN           : boolean                        := false;         -- implement custom functions subsystem (CFS)

    -- Smart LED interface (NEOLED) --
    IO_NEOLED_EN        : boolean                        := false;         -- implement NeoPixel-compatible smart LED interface (NEOLED)
    IO_NEOLED_TX_FIFO   : natural range 1 to 2**15       := 1;             -- NEOLED FIFO depth, has to be a power of two

    -- General-Purpose Timer (GPTMR) --
    IO_GPTMR_NUM        : natural range 0 to 16          := 0;             -- number of GPTMR timer slices to implement (0..16)

    -- 1-Wire Interface (ONEWIRE) --
    IO_ONEWIRE_EN       : boolean                        := false;         -- implement 1-wire interface (ONEWIRE)
    IO_ONEWIRE_FIFO     : natural range 1 to 2**15       := 1;             -- RTX FIFO depth, has to be zero or a power of two

    -- Direct Memory Access Controller (DMA) --
    IO_DMA_EN           : boolean                        := false;         -- implement direct memory access controller (DMA)
    IO_DMA_DSC_FIFO     : natural range 4 to 512         := 4;             -- DMA descriptor FIFO depth, has to be a power of two

    -- Stream Link Interface (SLINK) --
    IO_SLINK_EN         : boolean                        := false;         -- implement stream link interface (SLINK)
    IO_SLINK_RX_FIFO    : natural range 1 to 2**15       := 1;             -- RX FIFO depth, has to be a power of two
    IO_SLINK_TX_FIFO    : natural range 1 to 2**15       := 1;             -- TX FIFO depth, has to be a power of two

    -- Instruction Tracer (TRACER) --
    IO_TRACER_EN        : boolean                        := false;         -- implement instruction tracer
    IO_TRACER_BUFFER    : natural range 1 to 2**15       := 1;             -- trace buffer depth, has to be a power of two
    IO_TRACER_SIMLOG_EN : boolean                        := false          -- write full trace log to file (simulation-only)
  );
  port (
    -- Global control --
    clk_i          : in  std_ulogic;                                         -- global clock, rising edge
    rstn_i         : in  std_ulogic;                                         -- global reset, low-active, async
    rstn_ocd_o     : out std_ulogic;                                         -- on-chip debugger reset output, low-active, sync
    rstn_wdt_o     : out std_ulogic;                                         -- watchdog reset output, low-active, sync

    -- Execution trace (available if TRACE_PORT_EN = true) --
    trace_cpu0_o   : out trace_port_t;                                       -- CPU 0 trace port
    trace_cpu1_o   : out trace_port_t;                                       -- CPU 1 trace port

    -- JTAG on-chip debugger interface (available if OCD_EN = true) --
    jtag_tck_i     : in  std_ulogic := 'L';                                  -- serial clock
    jtag_tdi_i     : in  std_ulogic := 'L';                                  -- serial data input
    jtag_tdo_o     : out std_ulogic;                                         -- serial data output
    jtag_tms_i     : in  std_ulogic := 'L';                                  -- mode select

    -- Serial memory controller interface (available if SMC_EN = true) --
    smc_ioen_o     : out std_ulogic;                                         -- SMC pin enable, can be used for IO multiplexing
    smc_sck_o      : out std_ulogic;                                         -- clock
    smc_csn_o      : out std_ulogic_vector(1 downto 0);                      -- bank/chip select, low-active
    smc_sdo_o      : out std_ulogic;                                         -- controller data out, memory data in
    smc_sdi_i      : in  std_ulogic := 'L';                                  -- controller data in, memory data out

    -- External bus interface (available if XBUS_EN = true) --
    xbus_adr_o     : out std_ulogic_vector(31 downto 0);                     -- address
    xbus_dat_o     : out std_ulogic_vector(31 downto 0);                     -- write data
    xbus_cti_o     : out std_ulogic_vector(2 downto 0);                      -- cycle type
    xbus_tag_o     : out std_ulogic_vector(2 downto 0);                      -- access tag
    xbus_we_o      : out std_ulogic;                                         -- read/write
    xbus_sel_o     : out std_ulogic_vector(3 downto 0);                      -- byte enable
    xbus_stb_o     : out std_ulogic;                                         -- strobe
    xbus_cyc_o     : out std_ulogic;                                         -- valid cycle
    xbus_dat_i     : in  std_ulogic_vector(31 downto 0) := (others => 'L');  -- read data
    xbus_ack_i     : in  std_ulogic := 'L';                                  -- transfer acknowledge
    xbus_err_i     : in  std_ulogic := 'L';                                  -- transfer error

    -- Stream link interface (available if IO_SLINK_EN = true) --
    slink_rx_dat_i : in  std_ulogic_vector(31 downto 0) := (others => 'L');  -- RX input data
    slink_rx_src_i : in  std_ulogic_vector(3 downto 0)  := (others => 'L');  -- RX source routing information
    slink_rx_val_i : in  std_ulogic := 'L';                                  -- RX valid input
    slink_rx_lst_i : in  std_ulogic := 'L';                                  -- RX last element of stream
    slink_rx_rdy_o : out std_ulogic;                                         -- RX ready to receive
    slink_tx_dat_o : out std_ulogic_vector(31 downto 0);                     -- TX output data
    slink_tx_dst_o : out std_ulogic_vector(3 downto 0);                      -- TX destination routing information
    slink_tx_val_o : out std_ulogic;                                         -- TX valid output
    slink_tx_lst_o : out std_ulogic;                                         -- TX last element of stream
    slink_tx_rdy_i : in  std_ulogic := 'L';                                  -- TX ready to send

    -- GPIO (available if IO_GPIO_NUM > 0) --
    gpio_dir_o     : out std_ulogic_vector(31 downto 0);                     -- direction control (0=in, 1=out)
    gpio_o         : out std_ulogic_vector(31 downto 0);                     -- parallel output
    gpio_i         : in  std_ulogic_vector(31 downto 0) := (others => 'L');  -- parallel input; interrupt-capable

    -- Primary UART0 (available if IO_UART0_EN = true) --
    uart0_txd_o    : out std_ulogic;                                         -- UART0 send data
    uart0_rxd_i    : in  std_ulogic := 'L';                                  -- UART0 receive data
    uart0_rtsn_o   : out std_ulogic;                                         -- HW flow control: UART0.RX ready to receive ("RTR"), low-active, optional
    uart0_ctsn_i   : in  std_ulogic := 'L';                                  -- HW flow control: UART0.TX allowed to transmit, low-active, optional

    -- Secondary UART1 (available if IO_UART1_EN = true) --
    uart1_txd_o    : out std_ulogic;                                         -- UART1 send data
    uart1_rxd_i    : in  std_ulogic := 'L';                                  -- UART1 receive data
    uart1_rtsn_o   : out std_ulogic;                                         -- HW flow control: UART1.RX ready to receive ("RTR"), low-active, optional
    uart1_ctsn_i   : in  std_ulogic := 'L';                                  -- HW flow control: UART1.TX allowed to transmit, low-active, optional

    -- SPI (available if IO_SPI_EN = true) --
    spi_clk_o      : out std_ulogic;                                         -- SPI serial clock
    spi_dat_o      : out std_ulogic;                                         -- controller data out, peripheral data in
    spi_dat_i      : in  std_ulogic := 'L';                                  -- controller data in, peripheral data out
    spi_csn_o      : out std_ulogic_vector(7 downto 0);                      -- chip-select, low-active

    -- SDI (available if IO_SDI_EN = true) --
    sdi_clk_i      : in  std_ulogic := 'L';                                  -- SDI serial clock
    sdi_dat_o      : out std_ulogic;                                         -- controller data out, peripheral data in
    sdi_dat_i      : in  std_ulogic := 'L';                                  -- controller data in, peripheral data out
    sdi_csn_i      : in  std_ulogic := 'H';                                  -- chip-select, low-active

    -- TWI (available if IO_TWI_EN = true) --
    twi_sda_i      : in  std_ulogic := 'H';                                  -- serial data line sense input
    twi_sda_o      : out std_ulogic;                                         -- serial data line output (pull low only)
    twi_scl_i      : in  std_ulogic := 'H';                                  -- serial clock line sense input
    twi_scl_o      : out std_ulogic;                                         -- serial clock line output (pull low only)

    -- TWD (available if IO_TWD_EN = true) --
    twd_sda_i      : in  std_ulogic := 'H';                                  -- serial data line sense input
    twd_sda_o      : out std_ulogic;                                         -- serial data line output (pull low only)
    twd_scl_i      : in  std_ulogic := 'H';                                  -- serial clock line sense input

    -- 1-Wire Interface (available if IO_ONEWIRE_EN = true) --
    onewire_i      : in  std_ulogic := 'H';                                  -- 1-wire bus sense input
    onewire_o      : out std_ulogic;                                         -- 1-wire bus output (pull low only)

    -- PWM (available if IO_PWM_NUM > 0) --
    pwm_o          : out std_ulogic_vector(31 downto 0);                     -- PWM channels

    -- Custom Functions Subsystem IO (available if IO_CFS_EN = true) --
    cfs_in_i       : in  std_ulogic_vector(255 downto 0) := (others => 'L'); -- custom CFS inputs conduit
    cfs_out_o      : out std_ulogic_vector(255 downto 0);                    -- custom CFS outputs conduit

    -- NeoPixel-compatible smart LED interface (available if IO_NEOLED_EN = true) --
    neoled_o       : out std_ulogic;                                         -- async serial data line

    -- Machine timer system time (available if IO_CLINT_EN = true) --
    mtime_time_o   : out std_ulogic_vector(63 downto 0);                     -- current system time

    -- CPU interrupts --
    irq_msi_i      : in  std_ulogic := 'L';                                  -- machine software interrupt, available if IO_CLINT_EN = false
    irq_mti_i      : in  std_ulogic := 'L';                                  -- machine timer interrupt, available if IO_CLINT_EN = false
    irq_mei_i      : in  std_ulogic := 'L'                                   -- machine external interrupt
  );
end neorv32_top;

architecture neorv32_top_rtl of neorv32_top is

  -- ----------------------------------------------------------
  -- Boot Configuration (BOOT_MODE_SELECT)
  -- ----------------------------------------------------------
  -- 0: Internal bootloader ROM
  -- 1: Custom (use BOOT_ADDR_CUSTOM)
  -- 2: Internal IMEM initialized with application image
  -- ----------------------------------------------------------
  constant bootrom_en_c    : boolean := boolean(BOOT_MODE_SELECT = 0);
  constant imem_as_rom_c   : boolean := boolean(BOOT_MODE_SELECT = 2);
  constant cpu_boot_addr_c : std_ulogic_vector(31 downto 0) :=
    sel_suv_f(boolean(BOOT_MODE_SELECT = 0), base_io_bootrom_c,
    sel_suv_f(boolean(BOOT_MODE_SELECT = 1), BOOT_ADDR_CUSTOM,
    sel_suv_f(boolean(BOOT_MODE_SELECT = 2), IMEM_BASE, x"00000000")));

  -- auto-configuration --
  constant num_cores_c     : natural := sel_natural_f(DUAL_CORE_EN, 2, 1);
  constant io_gpio_en_c    : boolean := boolean(IO_GPIO_NUM > 0);
  constant io_pwm_en_c     : boolean := boolean(IO_PWM_NUM > 0);
  constant io_gptmr_en_c   : boolean := boolean(IO_GPTMR_NUM > 0);
  constant cpu_smpmp_en_c  : boolean := boolean(PMP_NUM_REGIONS > 0);
  constant ocd_auth_en_c   : boolean := OCD_EN and OCD_AUTHENTICATION;
  constant cpu_sdtrig_en_c : boolean := OCD_EN and boolean(OCD_NUM_HW_TRIGGERS > 0);
  constant trace_en_c      : boolean := TRACE_PORT_EN or IO_TRACER_EN;
  constant vendorid_c      : std_ulogic_vector(31 downto 0) := x"00000" & '0' & OCD_JEDEC_ID;
  constant bursts_en_c     : boolean := CACHE_BURSTS_EN and (ICACHE_EN or DCACHE_EN) and boolean(CACHE_BLOCK_SIZE >= 8);

  -- make sure physical memory sizes are a power of two --
  constant imem_size_c : natural := 2**index_size_f(IMEM_SIZE);
  constant dmem_size_c : natural := 2**index_size_f(DMEM_SIZE);

  -- reset nets --
  signal rstn_wdt, rstn_sys, rstn_ext : std_ulogic;

  -- pre-scaled clocks (clock enables) --
  signal clk_gen : std_ulogic_vector(7 downto 0);

  -- debug module interface (DMI) --
  signal dmi_req : dmi_req_t;
  signal dmi_rsp : dmi_rsp_t;

  -- debug core interface (DCI) --
  signal dci_ndmrstn : std_ulogic;
  signal dci_haltreq : std_ulogic_vector(num_cores_c-1 downto 0);

  -- CPU trace interface --
  type cpu_trace_t is array (0 to num_cores_c-1) of trace_port_t;
  signal cpu_trace : cpu_trace_t;

  -- CPU memory ordering (cache synchronization) --
  signal cpu_i_fence, cpu_d_fence, icache_sync, dcache_sync : std_ulogic_vector(num_cores_c-1 downto 0);

  -- bus: CPU core complex --
  type core_complex_req_t is array (0 to num_cores_c-1) of bus_req_t;
  type core_complex_rsp_t is array (0 to num_cores_c-1) of bus_rsp_t;
  signal cpu_i_req, cpu_d_req, icache_req, dcache_req, core_req : core_complex_req_t;
  signal cpu_i_rsp, cpu_d_rsp, icache_rsp, dcache_rsp, core_rsp : core_complex_rsp_t;

  -- bus: system --
  signal sys1_req, sys2_req, dma_req, amo_req, sys3_req, imem_req, dmem_req, smc_req, io_req, xbus_req : bus_req_t;
  signal sys1_rsp, sys2_rsp, dma_rsp, amo_rsp, sys3_rsp, imem_rsp, dmem_rsp, smc_rsp, io_rsp, xbus_rsp : bus_rsp_t;
  signal xbus_terminate : std_ulogic;

  -- bus: IO devices --
  type io_devices_enum_t is (
    IODEV_BOOTROM, IODEV_OCD, IODEV_SYSINFO, IODEV_NEOLED, IODEV_GPIO, IODEV_WDT, IODEV_TRNG,
    IODEV_TWI, IODEV_SPI, IODEV_SDI, IODEV_UART1, IODEV_UART0, IODEV_CLINT, IODEV_ONEWIRE,
    IODEV_GPTMR, IODEV_PWM, IODEV_DMA, IODEV_SLINK, IODEV_CFS, IODEV_TWD, IODEV_TRACER, IODEV_SMC
  );
  type iodev_req_t is array (io_devices_enum_t) of bus_req_t;
  type iodev_rsp_t is array (io_devices_enum_t) of bus_rsp_t;
  signal iodev_req : iodev_req_t;
  signal iodev_rsp : iodev_rsp_t;

  -- fast interrupts (FIRQ) --
  type firq_enum_t is (
    FIRQ_TWD, FIRQ_UART0, FIRQ_UART1, FIRQ_SPI, FIRQ_SDI, FIRQ_TWI, FIRQ_CFS, FIRQ_NEOLED,
    FIRQ_GPIO, FIRQ_GPTMR, FIRQ_ONEWIRE, FIRQ_DMA, FIRQ_SLINK, FIRQ_TRNG, FIRQ_TRACER
  );
  type firq_t is array (firq_enum_t) of std_ulogic;
  signal firq     : firq_t;
  signal cpu_firq : std_ulogic_vector(15 downto 0);
  signal mti, msi : std_ulogic_vector(num_cores_c-1 downto 0);

  -- system time (mtime) --
  signal mtime    : std_ulogic_vector(63 downto 0);
  signal mtime_lo : std_ulogic_vector(31 downto 0);

begin

  -- **************************************************************************************************************************
  -- Configuration Checks
  -- **************************************************************************************************************************

  config_checks:
  if true generate

    -- say hello --
    assert false report
      "[NEORV32] The NEORV32 RISC-V Processor (v" &
      to_hexstring_f(hw_version_c(31 downto 24)) & "." &
      to_hexstring_f(hw_version_c(23 downto 16)) & "." &
      to_hexstring_f(hw_version_c(15 downto 8))  & "." &
      to_hexstring_f(hw_version_c(7 downto 0))   &
      "), github.com/stnolting/neorv32" severity note;

    -- show SoC configuration --
    assert false report
      "[NEORV32] Processor Configuration: CPU " & -- cpu core is always enabled
      sel_string_f(boolean(num_cores_c = 1), "(single-core) ",   "") &
      sel_string_f(boolean(num_cores_c = 2), "(smp-dual-core) ", "") &
      sel_string_f(IMEM_EN,         sel_string_f(imem_as_rom_c, "IMEM-ROM ", "IMEM "), "") &
      sel_string_f(DMEM_EN,         "DMEM ",     "") &
      sel_string_f(bootrom_en_c,    "BOOTROM ",  "") &
      sel_string_f(ICACHE_EN,       "I-CACHE ",  "") &
      sel_string_f(DCACHE_EN,       "D-CACHE ",  "") &
      sel_string_f(SMC_EN,          "SMC ",      "") &
      sel_string_f(XBUS_EN,         "XBUS ",     "") &
      sel_string_f(IO_CLINT_EN,     "CLINT ",    "") &
      sel_string_f(io_gpio_en_c,    "GPIO ",     "") &
      sel_string_f(IO_UART0_EN,     "UART0 ",    "") &
      sel_string_f(IO_UART1_EN,     "UART1 ",    "") &
      sel_string_f(IO_SPI_EN,       "SPI ",      "") &
      sel_string_f(IO_SDI_EN,       "SDI ",      "") &
      sel_string_f(IO_TWI_EN,       "TWI ",      "") &
      sel_string_f(IO_TWD_EN,       "TWD ",      "") &
      sel_string_f(io_pwm_en_c,     "PWM ",      "") &
      sel_string_f(IO_WDT_EN,       "WDT ",      "") &
      sel_string_f(IO_TRNG_EN,      "TRNG ",     "") &
      sel_string_f(IO_CFS_EN,       "CFS ",      "") &
      sel_string_f(IO_NEOLED_EN,    "NEOLED ",   "") &
      sel_string_f(io_gptmr_en_c,   "GPTMR ",    "") &
      sel_string_f(IO_ONEWIRE_EN,   "ONEWIRE ",  "") &
      sel_string_f(IO_DMA_EN,       "DMA ",      "") &
      sel_string_f(IO_SLINK_EN,     "SLINK ",    "") &
      sel_string_f(true,            "SYSINFO ",  "") & -- always enabled
      sel_string_f(IO_TRACER_EN,    "TRACER ",   "") &
      sel_string_f(OCD_EN,          "OCD ",      "") &
      sel_string_f(ocd_auth_en_c,   "OCD-AUTH ", "") &
      sel_string_f(cpu_sdtrig_en_c, "OCD-HWBP ", "") &
      ""
      severity note;

    -- simulation notifier --
    assert not is_simulation_c report
      "[NEORV32] Assuming this is a simulation." severity warning;

    -- clock speed not defined --
    assert (CLOCK_FREQUENCY > 0) report
      "[NEORV32] CLOCK_FREQUENCY must be configured according to the frequency of clk_i port!" severity warning;

    -- boot configuration notifier --
    assert not (BOOT_MODE_SELECT = 0) report
      "[NEORV32] BOOT_MODE_SELECT 0 - booting via bootloader" severity note;
    assert not (BOOT_MODE_SELECT = 1) report
      "[NEORV32] BOOT_MODE_SELECT 1 - booting from custom address" severity note;
    assert not (BOOT_MODE_SELECT = 2) report
      "[NEORV32] BOOT_MODE_SELECT 2 - booting IMEM image" severity note;

    -- boot configuration: boot from initialized IMEM requires the IMEM to be enabled --
    assert not ((BOOT_MODE_SELECT = 2) and (not IMEM_EN)) report
      "[NEORV32] BOOT_MODE_SELECT = 2 (boot IMEM image) requires the internal instruction memory (IMEM)!" severity error;

    -- SMP dual-core configuration requires the CLINT --
    assert not (DUAL_CORE_EN and (not IO_CLINT_EN)) report
      "[NEORV32] SMP dual-core configuration requires the CLINT!" severity error;

    -- custom IMEM address --
    assert not (IMEM_EN and (IMEM_BASE /= x"00000000")) report
      "[NEORV32] Using non-default IMEM base address. Configure SW framework accordingly." severity warning;
    assert (or_reduce_f(IMEM_BASE(index_size_f(imem_size_c)-1 downto 0)) = '0') report
      "[NEORV32] IMEM base address has to be naturally aligned to its size!" severity error;

    -- custom DMEM address --
    assert not (DMEM_EN and (DMEM_BASE /= x"80000000")) report
      "[NEORV32] Using non-default DMEM base address. Configure SW framework accordingly." severity warning;
    assert (or_reduce_f(DMEM_BASE(index_size_f(dmem_size_c)-1 downto 0)) = '0') report
      "[NEORV32] DMEM base address has to be naturally aligned to its size!" severity error;

    -- custom SMC address --
    assert (or_reduce_f(SMC_BASE(27 downto 0)) = '0') report
      "[NEORV32] SMC base address has to be 256MB aligned!" severity error;

    -- uncached base address alignment --
    assert (CACHE_UC_BASE(27 downto 0) = x"0000000") report
      "[NEORV32] Base address of uncached address space has to be 256MB-aligned!" severity error;

  end generate;

  -- **************************************************************************************************************************
  -- Clock and Reset Generators
  -- **************************************************************************************************************************

  soc_generators:
  if true generate

    -- Reset Sequencer --
    neorv32_sys_reset_inst: entity neorv32.neorv32_sys_reset
    port map (
      clk_i       => clk_i,
      rstn_ext_i  => rstn_i,
      rstn_wdt_i  => rstn_wdt,
      rstn_dbg_i  => dci_ndmrstn,
      rstn_ext_o  => rstn_ext,
      rstn_sys_o  => rstn_sys,
      xrstn_wdt_o => rstn_wdt_o,
      xrstn_ocd_o => rstn_ocd_o
    );

    -- Clock Divider / Pulse Generator --
    neorv32_sys_clock_inst: entity neorv32.neorv32_sys_clock
    port map (
      clk_i    => clk_i,
      rstn_i   => rstn_sys,
      enable_i => '1',
      clk_en_o => clk_gen
    );

  end generate;

  -- **************************************************************************************************************************
  -- Core Complex
  -- **************************************************************************************************************************

  -- fast interrupt requests (FIRQs) --
  cpu_firq(0)  <= '0'; -- reserved
  cpu_firq(1)  <= firq(FIRQ_CFS);
  cpu_firq(2)  <= firq(FIRQ_UART0);
  cpu_firq(3)  <= firq(FIRQ_UART1);
  cpu_firq(4)  <= firq(FIRQ_TWD);
  cpu_firq(5)  <= firq(FIRQ_TRACER);
  cpu_firq(6)  <= firq(FIRQ_SPI);
  cpu_firq(7)  <= firq(FIRQ_TWI);
  cpu_firq(8)  <= firq(FIRQ_GPIO);
  cpu_firq(9)  <= firq(FIRQ_NEOLED);
  cpu_firq(10) <= firq(FIRQ_DMA);
  cpu_firq(11) <= firq(FIRQ_SDI);
  cpu_firq(12) <= firq(FIRQ_GPTMR);
  cpu_firq(13) <= firq(FIRQ_ONEWIRE);
  cpu_firq(14) <= firq(FIRQ_SLINK);
  cpu_firq(15) <= firq(FIRQ_TRNG);

  -- CPU core(s) + optional caches + bus switch --
  core_complex_gen:
  for i in 0 to num_cores_c-1 generate

    -- CPU Core -------------------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_cpu_inst: entity neorv32.neorv32_cpu
    generic map (
      -- General --
      HART_ID             => i,
      VENDOR_ID           => vendorid_c,
      BOOT_ADDR           => cpu_boot_addr_c,
      DEBUG_PARK_ADDR     => dm_park_entry_c,
      DEBUG_EXC_ADDR      => dm_exc_entry_c,
      -- RISC-V ISA Extensions --
      RISCV_ISA_C         => RISCV_ISA_C,
      RISCV_ISA_E         => RISCV_ISA_E,
      RISCV_ISA_M         => RISCV_ISA_M,
      RISCV_ISA_U         => RISCV_ISA_U,
      RISCV_ISA_Zaamo     => RISCV_ISA_Zaamo,
      RISCV_ISA_Zalrsc    => RISCV_ISA_Zalrsc,
      RISCV_ISA_Zba       => RISCV_ISA_Zba,
      RISCV_ISA_Zbb       => RISCV_ISA_Zbb,
      RISCV_ISA_Zbc       => RISCV_ISA_Zbc,
      RISCV_ISA_Zbkb      => RISCV_ISA_Zbkb,
      RISCV_ISA_Zbkc      => RISCV_ISA_Zbkc,
      RISCV_ISA_Zbkx      => RISCV_ISA_Zbkx,
      RISCV_ISA_Zbs       => RISCV_ISA_Zbs,
      RISCV_ISA_Zcb       => RISCV_ISA_Zcb,
      RISCV_ISA_Zcmop     => RISCV_ISA_Zcmop,
      RISCV_ISA_Zfinx     => RISCV_ISA_Zfinx,
      RISCV_ISA_Zibi      => RISCV_ISA_Zibi,
      RISCV_ISA_Zicntr    => RISCV_ISA_Zicntr,
      RISCV_ISA_Zicond    => RISCV_ISA_Zicond,
      RISCV_ISA_Zihpm     => RISCV_ISA_Zihpm,
      RISCV_ISA_Zimop     => RISCV_ISA_Zimop,
      RISCV_ISA_Zknd      => RISCV_ISA_Zknd,
      RISCV_ISA_Zkne      => RISCV_ISA_Zkne,
      RISCV_ISA_Zknh      => RISCV_ISA_Zknh,
      RISCV_ISA_Zksed     => RISCV_ISA_Zksed,
      RISCV_ISA_Zksh      => RISCV_ISA_Zksh,
      RISCV_ISA_Zmmul     => RISCV_ISA_Zmmul,
      RISCV_ISA_Sdext     => OCD_EN,
      RISCV_ISA_Sdtrig    => cpu_sdtrig_en_c,
      RISCV_ISA_Smcntrpmf => RISCV_ISA_Smcntrpmf,
      RISCV_ISA_Smpmp     => cpu_smpmp_en_c,
      RISCV_ISA_Xcfu      => RISCV_ISA_Xcfu,
      -- Tuning Options --
      CPU_TRACE_EN        => trace_en_c,
      CPU_CONSTT_BR_EN    => CPU_CONSTT_BR_EN,
      CPU_FAST_MUL_EN     => CPU_FAST_MUL_EN,
      CPU_FAST_SHIFT_EN   => CPU_FAST_SHIFT_EN,
      CPU_RF_ARCH_SEL     => CPU_RF_ARCH_SEL,
      -- Physical Memory Protection (PMP) --
      PMP_NUM_REGIONS     => PMP_NUM_REGIONS,
      PMP_MIN_GRANULARITY => PMP_MIN_GRANULARITY,
      PMP_TOR_MODE_EN     => PMP_TOR_MODE_EN,
      PMP_NAP_MODE_EN     => PMP_NAP_MODE_EN,
      -- Hardware Performance Monitors (HPM) --
      HPM_NUM_CNTS        => HPM_NUM_CNTS,
      HPM_CNT_WIDTH       => HPM_CNT_WIDTH,
      -- Trigger Module (TM) --
      NUM_HW_TRIGGERS     => OCD_NUM_HW_TRIGGERS
    )
    port map (
      -- global control --
      clk_i      => clk_i,
      rstn_i     => rstn_sys,
      -- status --
      mtime_i    => mtime,
      trace_o    => cpu_trace(i),
      sleep_o    => open,
      -- interrupts --
      msi_i      => msi(i),
      mei_i      => irq_mei_i,
      mti_i      => mti(i),
      firq_i     => cpu_firq,
      dbi_i      => dci_haltreq(i),
      -- instruction bus interface --
      ifence_o   => cpu_i_fence(i),
      ibus_req_o => cpu_i_req(i),
      ibus_rsp_i => cpu_i_rsp(i),
      -- data bus interface --
      dfence_o   => cpu_d_fence(i),
      dbus_req_o => cpu_d_req(i),
      dbus_rsp_i => cpu_d_rsp(i)
    );

    -- CPU Instruction Cache ------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_icache_enabled:
    if ICACHE_EN generate
      neorv32_icache_inst: entity neorv32.neorv32_cache
      generic map (
        NUM_BLOCKS => ICACHE_NUM_BLOCKS,
        BLOCK_SIZE => CACHE_BLOCK_SIZE,
        UC_BEGIN   => CACHE_UC_BASE(31 downto 28),
        READ_ONLY  => true,
        BURSTS_EN  => bursts_en_c
      )
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        sync_i     => icache_sync(i),
        host_req_i => cpu_i_req(i),
        host_rsp_o => cpu_i_rsp(i),
        bus_req_o  => icache_req(i),
        bus_rsp_i  => icache_rsp(i)
      );
      -- fence.i => clear I$
      icache_sync(i) <= cpu_i_fence(i);
    end generate;

    neorv32_icache_disabled:
    if not ICACHE_EN generate
      icache_sync(i) <= '0';
      icache_req(i)  <= cpu_i_req(i);
      cpu_i_rsp(i)   <= icache_rsp(i);
    end generate;

    -- CPU Data Cache -------------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_dcache_enabled:
    if DCACHE_EN generate
      neorv32_dcache_inst: entity neorv32.neorv32_cache
      generic map (
        NUM_BLOCKS => DCACHE_NUM_BLOCKS,
        BLOCK_SIZE => CACHE_BLOCK_SIZE,
        UC_BEGIN   => CACHE_UC_BASE(31 downto 28),
        READ_ONLY  => false,
        BURSTS_EN  => bursts_en_c
      )
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        sync_i     => dcache_sync(i),
        host_req_i => cpu_d_req(i),
        host_rsp_o => cpu_d_rsp(i),
        bus_req_o  => dcache_req(i),
        bus_rsp_i  => dcache_rsp(i)
      );
      -- fence   => flush D$
      -- fence.i => clear I$ and flush D$ (so I$ gets updated data #1540)
      dcache_sync(i) <= cpu_d_fence(i) or cpu_i_fence(i);
    end generate;

    neorv32_dcache_disabled:
    if not DCACHE_EN generate
      dcache_sync(i) <= '0';
      dcache_req(i)  <= cpu_d_req(i);
      cpu_d_rsp(i)   <= dcache_rsp(i);
    end generate;

    -- Core Instruction/Data Bus Switch -------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_core_bus_switch_inst: entity neorv32.neorv32_bus_switch
    generic map (
      ROUND_ROBIN_EN => false, -- use prioritizing arbitration
      A_READ_ONLY    => false,
      B_READ_ONLY    => true -- instruction fetch is read-only
    )
    port map (
      clk_i   => clk_i,
      rstn_i  => rstn_sys,
      a_req_i => dcache_req(i), -- data accesses are prioritized
      a_rsp_o => dcache_rsp(i),
      b_req_i => icache_req(i),
      b_rsp_o => icache_rsp(i),
      x_req_o => core_req(i),
      x_rsp_i => core_rsp(i)
    );

  end generate;

  -- CPU execution trace ports --
  trace_cpu0_o <= cpu_trace(core_req'left);
  trace_cpu1_o <= cpu_trace(core_req'right) when (num_cores_c = 2) else trace_port_terminate_c;

  -- Core Complex Bus Arbiter ---------------------------------------------------------------
  -- -------------------------------------------------------------------------------------------
  core_complex_dual:
  if num_cores_c = 2 generate
    neorv32_complex_arbiter_inst: entity neorv32.neorv32_bus_switch
    generic map (
      ROUND_ROBIN_EN => true, -- fair (and lockable) scheduling
      A_READ_ONLY    => false,
      B_READ_ONLY    => false
    )
    port map (
      clk_i   => clk_i,
      rstn_i  => rstn_sys,
      a_req_i => core_req(core_req'left),
      a_rsp_o => core_rsp(core_rsp'left),
      b_req_i => core_req(core_req'right),
      b_rsp_o => core_rsp(core_rsp'right),
      x_req_o => sys1_req,
      x_rsp_i => sys1_rsp
    );
  end generate;

  core_complex_single:
  if num_cores_c = 1 generate
    sys1_req    <= core_req(0);
    core_rsp(0) <= sys1_rsp;
  end generate;

  -- **************************************************************************************************************************
  -- Direct Memory Access Controller (DMA) Complex
  -- **************************************************************************************************************************

  neorv32_dma_complex_enabled:
  if IO_DMA_EN generate

    -- DMA Controller -------------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_dma_inst: entity neorv32.neorv32_dma
    generic map (
      DSC_FIFO => IO_DMA_DSC_FIFO
    )
    port map (
      clk_i     => clk_i,
      rstn_i    => rstn_sys,
      bus_req_i => iodev_req(IODEV_DMA),
      bus_rsp_o => iodev_rsp(IODEV_DMA),
      dma_req_o => dma_req,
      dma_rsp_i => dma_rsp,
      irq_o     => firq(FIRQ_DMA)
    );

    -- DMA Bus Switch -------------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_dma_bus_switch_inst: entity neorv32.neorv32_bus_switch
    generic map (
      ROUND_ROBIN_EN => false, -- use prioritizing arbitration
      A_READ_ONLY    => false,
      B_READ_ONLY    => false
    )
    port map (
      clk_i   => clk_i,
      rstn_i  => rstn_sys,
      a_req_i => sys1_req, -- CPU accesses are prioritized
      a_rsp_o => sys1_rsp,
      b_req_i => dma_req,
      b_rsp_o => dma_rsp,
      x_req_o => sys2_req,
      x_rsp_i => sys2_rsp
    );

  end generate;

  neorv32_dma_complex_disabled:
  if not IO_DMA_EN generate
    iodev_rsp(IODEV_DMA) <= rsp_terminate_c;
    sys2_req             <= sys1_req;
    sys1_rsp             <= sys2_rsp;
    firq(FIRQ_DMA)       <= '0';
    dma_req              <= req_terminate_c;
    dma_rsp              <= rsp_terminate_c;
  end generate;

  -- **************************************************************************************************************************
  -- Atomic Memory Operations
  -- **************************************************************************************************************************

  atomics:
  if true generate

    -- Read-Modify-Write Controller -----------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_bus_amo_rmw_enabled:
    if RISCV_ISA_Zaamo generate
      neorv32_bus_amo_rmw_inst: entity neorv32.neorv32_bus_amo_rmw
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        core_req_i => sys2_req,
        core_rsp_o => sys2_rsp,
        sys_req_o  => amo_req,
        sys_rsp_i  => amo_rsp
      );
    end generate;

    neorv32_bus_amo_rmw_disabled:
    if not RISCV_ISA_Zaamo generate
      amo_req  <= sys2_req;
      sys2_rsp <= amo_rsp;
    end generate;

    -- Reservation-Set Controller -------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_bus_amo_rvs_enabled:
    if RISCV_ISA_Zalrsc generate
      neorv32_bus_amo_rvs_inst: entity neorv32.neorv32_bus_amo_rvs
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        core_req_i => amo_req,
        core_rsp_o => amo_rsp,
        sys_req_o  => sys3_req,
        sys_rsp_i  => sys3_rsp
      );
    end generate;

    neorv32_bus_amo_rvs_disabled:
    if not RISCV_ISA_Zalrsc generate
      sys3_req <= amo_req;
      amo_rsp  <= sys3_rsp;
    end generate;

  end generate;

  -- **************************************************************************************************************************
  -- Address Region Gateway
  -- **************************************************************************************************************************

  neorv32_bus_gateway_inst: entity neorv32.neorv32_bus_gateway
  generic map (
    -- port A: internal IMEM --
    A_EN    => IMEM_EN,
    A_BASE  => IMEM_BASE,
    A_SIZE  => imem_size_c,
    A_TMO   => int_bus_tmo_c,
    -- port B: internal DMEM --
    B_EN    => DMEM_EN,
    B_BASE  => DMEM_BASE,
    B_SIZE  => dmem_size_c,
    B_TMO   => int_bus_tmo_c,
    -- port C: internal serial memory controller --
    C_EN    => SMC_EN,
    C_BASE  => SMC_BASE,
    C_SIZE  => 256*1024*1024, -- 256MB
    C_TMO   => 2048, -- maximum SMC transfer duration + safety margin
    -- port D: internal IO --
    D_EN    => true,
    D_BASE  => mem_io_base_c,
    D_SIZE  => mem_io_size_c,
    D_TMO   => int_bus_tmo_c,
    -- port X (the void): XBUS --
    X_EN    => XBUS_EN,
    X_TMO   => XBUS_TIMEOUT
  )
  port map (
    -- global control --
    clk_i   => clk_i,
    rstn_i  => rstn_sys,
    term_o  => xbus_terminate,
    -- host port --
    req_i   => sys3_req,
    rsp_o   => sys3_rsp,
    -- section ports --
    a_req_o => imem_req,
    a_rsp_i => imem_rsp,
    b_req_o => dmem_req,
    b_rsp_i => dmem_rsp,
    c_req_o => smc_req,
    c_rsp_i => smc_rsp,
    d_req_o => io_req,
    d_rsp_i => io_rsp,
    x_req_o => xbus_req,
    x_rsp_i => xbus_rsp
  );

  -- **************************************************************************************************************************
  -- Memory System
  -- **************************************************************************************************************************

  memory_system:
  if true generate

    -- Processor-Internal Instruction Memory (IMEM) -------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_imem_enabled:
    if IMEM_EN generate
      neorv32_imem_inst: entity neorv32.neorv32_imem
      generic map (
        MEM_SIZE => imem_size_c,
        MEM_INIT => imem_as_rom_c,
        OUTREG   => IMEM_OUTREG_EN
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => imem_req,
        bus_rsp_o => imem_rsp
      );
    end generate;

    neorv32_imem_disabled:
    if not IMEM_EN generate
      imem_rsp <= rsp_terminate_c;
    end generate;

    -- Processor-Internal Data Memory (DMEM) --------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_dmem_enabled:
    if DMEM_EN generate
      neorv32_dmem_inst: entity neorv32.neorv32_dmem
      generic map (
        MEM_SIZE => dmem_size_c,
        OUTREG   => DMEM_OUTREG_EN
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => dmem_req,
        bus_rsp_o => dmem_rsp
      );
    end generate;

    neorv32_dmem_disabled:
    if not DMEM_EN generate
      dmem_rsp <= rsp_terminate_c;
    end generate;

    -- Serial Memory Controller (SMC) ---------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_smc_enabled:
    if SMC_EN generate
      neorv32_smc_inst: entity neorv32.neorv32_smc
      generic map (
        BURST_EN   => bursts_en_c,
        BURST_SIZE => CACHE_BLOCK_SIZE,
        MEM_BASE   => SMC_BASE
      )
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        ctrl_req_i => iodev_req(IODEV_SMC),
        ctrl_rsp_o => iodev_rsp(IODEV_SMC),
        data_req_i => smc_req,
        data_rsp_o => smc_rsp,
        smc_ioen_o => smc_ioen_o,
        smc_sck_o  => smc_sck_o,
        smc_csn_o  => smc_csn_o,
        smc_sdo_o  => smc_sdo_o,
        smc_sdi_i  => smc_sdi_i
      );
    end generate;

    neorv32_smc_disabled:
    if not SMC_EN generate
      iodev_rsp(IODEV_SMC) <= rsp_terminate_c;
      smc_rsp              <= rsp_terminate_c;
      smc_ioen_o           <= '0';
      smc_sck_o            <= '0';
      smc_csn_o            <= (others => '1');
      smc_sdo_o            <= '0';
    end generate;


    -- External Bus Interface (XBUS) ----------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_xbus_enabled:
    if XBUS_EN generate
      neorv32_xbus_inst: entity neorv32.neorv32_xbus
      generic map (
        REGSTAGE_EN => XBUS_REGSTAGE_EN
      )
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        bus_term_i => xbus_terminate,
        bus_req_i  => xbus_req,
        bus_rsp_o  => xbus_rsp,
        xbus_adr_o => xbus_adr_o,
        xbus_dat_i => xbus_dat_i,
        xbus_dat_o => xbus_dat_o,
        xbus_cti_o => xbus_cti_o,
        xbus_tag_o => xbus_tag_o,
        xbus_we_o  => xbus_we_o,
        xbus_sel_o => xbus_sel_o,
        xbus_stb_o => xbus_stb_o,
        xbus_cyc_o => xbus_cyc_o,
        xbus_ack_i => xbus_ack_i,
        xbus_err_i => xbus_err_i
      );
    end generate;

    neorv32_xbus_disabled:
    if not XBUS_EN generate
      xbus_rsp   <= rsp_terminate_c;
      xbus_adr_o <= (others => '0');
      xbus_dat_o <= (others => '0');
      xbus_cti_o <= (others => '0');
      xbus_tag_o <= (others => '0');
      xbus_we_o  <= '0';
      xbus_sel_o <= (others => '0');
      xbus_stb_o <= '0';
      xbus_cyc_o <= '0';
    end generate;

  end generate;

  -- **************************************************************************************************************************
  -- IO/Peripheral Modules
  -- **************************************************************************************************************************

  io_system:
  if true generate

    -- IO Switch ------------------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_bus_io_switch_inst: entity neorv32.neorv32_bus_io_switch
    generic map (
      DEV_SIZE  => mem_io_dev_size_c,
      DEV_00_EN => bootrom_en_c,      DEV_00_BASE => base_io_bootrom_c,
      DEV_01_EN => false,             DEV_01_BASE => (others => '0'), -- reserved
      DEV_02_EN => false,             DEV_02_BASE => (others => '0'), -- reserved
      DEV_03_EN => false,             DEV_03_BASE => (others => '0'), -- reserved
      DEV_04_EN => false,             DEV_04_BASE => (others => '0'), -- reserved
      DEV_05_EN => false,             DEV_05_BASE => (others => '0'), -- reserved
      DEV_06_EN => false,             DEV_06_BASE => (others => '0'), -- reserved
      DEV_07_EN => false,             DEV_07_BASE => (others => '0'), -- reserved
      DEV_08_EN => false,             DEV_08_BASE => (others => '0'), -- reserved
      DEV_09_EN => false,             DEV_09_BASE => (others => '0'), -- reserved
      DEV_10_EN => IO_TWD_EN,         DEV_10_BASE => base_io_twd_c,
      DEV_11_EN => IO_CFS_EN,         DEV_11_BASE => base_io_cfs_c,
      DEV_12_EN => IO_SLINK_EN,       DEV_12_BASE => base_io_slink_c,
      DEV_13_EN => IO_DMA_EN,         DEV_13_BASE => base_io_dma_c,
      DEV_14_EN => false,             DEV_14_BASE => (others => '0'), -- reserved
      DEV_15_EN => SMC_EN,            DEV_15_BASE => base_io_smc_c,
      DEV_16_EN => io_pwm_en_c,       DEV_16_BASE => base_io_pwm_c,
      DEV_17_EN => io_gptmr_en_c,     DEV_17_BASE => base_io_gptmr_c,
      DEV_18_EN => IO_ONEWIRE_EN,     DEV_18_BASE => base_io_onewire_c,
      DEV_19_EN => IO_TRACER_EN,      DEV_19_BASE => base_io_tracer_c,
      DEV_20_EN => IO_CLINT_EN,       DEV_20_BASE => base_io_clint_c,
      DEV_21_EN => IO_UART0_EN,       DEV_21_BASE => base_io_uart0_c,
      DEV_22_EN => IO_UART1_EN,       DEV_22_BASE => base_io_uart1_c,
      DEV_23_EN => IO_SDI_EN,         DEV_23_BASE => base_io_sdi_c,
      DEV_24_EN => IO_SPI_EN,         DEV_24_BASE => base_io_spi_c,
      DEV_25_EN => IO_TWI_EN,         DEV_25_BASE => base_io_twi_c,
      DEV_26_EN => IO_TRNG_EN,        DEV_26_BASE => base_io_trng_c,
      DEV_27_EN => IO_WDT_EN,         DEV_27_BASE => base_io_wdt_c,
      DEV_28_EN => io_gpio_en_c,      DEV_28_BASE => base_io_gpio_c,
      DEV_29_EN => IO_NEOLED_EN,      DEV_29_BASE => base_io_neoled_c,
      DEV_30_EN => true,              DEV_30_BASE => base_io_sysinfo_c, -- always enabled
      DEV_31_EN => OCD_EN,            DEV_31_BASE => base_io_ocd_c
    )
    port map (
      clk_i        => clk_i,
      rstn_i       => rstn_sys,
      main_req_i   => io_req,
      main_rsp_o   => io_rsp,
      dev_00_req_o => iodev_req(IODEV_BOOTROM), dev_00_rsp_i => iodev_rsp(IODEV_BOOTROM),
      dev_01_req_o => open,                     dev_01_rsp_i => rsp_terminate_c, -- reserved
      dev_02_req_o => open,                     dev_02_rsp_i => rsp_terminate_c, -- reserved
      dev_03_req_o => open,                     dev_03_rsp_i => rsp_terminate_c, -- reserved
      dev_04_req_o => open,                     dev_04_rsp_i => rsp_terminate_c, -- reserved
      dev_05_req_o => open,                     dev_05_rsp_i => rsp_terminate_c, -- reserved
      dev_06_req_o => open,                     dev_06_rsp_i => rsp_terminate_c, -- reserved
      dev_07_req_o => open,                     dev_07_rsp_i => rsp_terminate_c, -- reserved
      dev_08_req_o => open,                     dev_08_rsp_i => rsp_terminate_c, -- reserved
      dev_09_req_o => open,                     dev_09_rsp_i => rsp_terminate_c, -- reserved
      dev_10_req_o => iodev_req(IODEV_TWD),     dev_10_rsp_i => iodev_rsp(IODEV_TWD),
      dev_11_req_o => iodev_req(IODEV_CFS),     dev_11_rsp_i => iodev_rsp(IODEV_CFS),
      dev_12_req_o => iodev_req(IODEV_SLINK),   dev_12_rsp_i => iodev_rsp(IODEV_SLINK),
      dev_13_req_o => iodev_req(IODEV_DMA),     dev_13_rsp_i => iodev_rsp(IODEV_DMA),
      dev_14_req_o => open,                     dev_14_rsp_i => rsp_terminate_c, -- reserved
      dev_15_req_o => iodev_req(IODEV_SMC),     dev_15_rsp_i => iodev_rsp(IODEV_SMC),
      dev_16_req_o => iodev_req(IODEV_PWM),     dev_16_rsp_i => iodev_rsp(IODEV_PWM),
      dev_17_req_o => iodev_req(IODEV_GPTMR),   dev_17_rsp_i => iodev_rsp(IODEV_GPTMR),
      dev_18_req_o => iodev_req(IODEV_ONEWIRE), dev_18_rsp_i => iodev_rsp(IODEV_ONEWIRE),
      dev_19_req_o => iodev_req(IODEV_TRACER),  dev_19_rsp_i => iodev_rsp(IODEV_TRACER),
      dev_20_req_o => iodev_req(IODEV_CLINT),   dev_20_rsp_i => iodev_rsp(IODEV_CLINT),
      dev_21_req_o => iodev_req(IODEV_UART0),   dev_21_rsp_i => iodev_rsp(IODEV_UART0),
      dev_22_req_o => iodev_req(IODEV_UART1),   dev_22_rsp_i => iodev_rsp(IODEV_UART1),
      dev_23_req_o => iodev_req(IODEV_SDI),     dev_23_rsp_i => iodev_rsp(IODEV_SDI),
      dev_24_req_o => iodev_req(IODEV_SPI),     dev_24_rsp_i => iodev_rsp(IODEV_SPI),
      dev_25_req_o => iodev_req(IODEV_TWI),     dev_25_rsp_i => iodev_rsp(IODEV_TWI),
      dev_26_req_o => iodev_req(IODEV_TRNG),    dev_26_rsp_i => iodev_rsp(IODEV_TRNG),
      dev_27_req_o => iodev_req(IODEV_WDT),     dev_27_rsp_i => iodev_rsp(IODEV_WDT),
      dev_28_req_o => iodev_req(IODEV_GPIO),    dev_28_rsp_i => iodev_rsp(IODEV_GPIO),
      dev_29_req_o => iodev_req(IODEV_NEOLED),  dev_29_rsp_i => iodev_rsp(IODEV_NEOLED),
      dev_30_req_o => iodev_req(IODEV_SYSINFO), dev_30_rsp_i => iodev_rsp(IODEV_SYSINFO),
      dev_31_req_o => iodev_req(IODEV_OCD),     dev_31_rsp_i => iodev_rsp(IODEV_OCD)
    );

    -- Processor-Internal Bootloader ROM (BOOTROM) --------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_bootrom_enabled:
    if bootrom_en_c generate
      neorv32_boot_rom_inst: entity neorv32.neorv32_bootrom
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_BOOTROM),
        bus_rsp_o => iodev_rsp(IODEV_BOOTROM)
      );
    end generate;

    neorv32_boot_rom_disabled:
    if not bootrom_en_c generate
      iodev_rsp(IODEV_BOOTROM) <= rsp_terminate_c;
    end generate;

    -- Custom Functions Subsystem (CFS) -------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_cfs_enabled:
    if IO_CFS_EN generate
      neorv32_cfs_inst: entity neorv32.neorv32_cfs
      port map (
        clk_i       => clk_i,
        rstn_i      => rstn_sys,
        bus_req_i   => iodev_req(IODEV_CFS),
        bus_rsp_o   => iodev_rsp(IODEV_CFS),
        irq_o       => firq(FIRQ_CFS),
        cfs_in_i    => cfs_in_i,
        cfs_out_o   => cfs_out_o
      );
    end generate;

    neorv32_cfs_disabled:
    if not IO_CFS_EN generate
      iodev_rsp(IODEV_CFS) <= rsp_terminate_c;
      firq(FIRQ_CFS)       <= '0';
      cfs_out_o            <= (others => '0');
    end generate;

    -- Serial Data Interface (SDI) ------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_sdi_enabled:
    if IO_SDI_EN generate
      neorv32_sdi_inst: entity neorv32.neorv32_sdi
      generic map (
        RTX_FIFO => IO_SDI_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_SDI),
        bus_rsp_o => iodev_rsp(IODEV_SDI),
        sdi_csn_i => sdi_csn_i,
        sdi_clk_i => sdi_clk_i,
        sdi_dat_i => sdi_dat_i,
        sdi_dat_o => sdi_dat_o,
        irq_o     => firq(FIRQ_SDI)
      );
    end generate;

    neorv32_sdi_disabled:
    if not IO_SDI_EN generate
      iodev_rsp(IODEV_SDI) <= rsp_terminate_c;
      sdi_dat_o            <= '0';
      firq(FIRQ_SDI)       <= '0';
    end generate;

    -- General Purpose Input/Output Port (GPIO) -----------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_gpio_enabled:
    if io_gpio_en_c generate
      neorv32_gpio_inst: entity neorv32.neorv32_gpio
      generic map (
        GPIO_NUM => IO_GPIO_NUM,
        GPIO_DIR => IO_GPIO_DIR_EN
      )
      port map (
        clk_i      => clk_i,
        rstn_i     => rstn_sys,
        bus_req_i  => iodev_req(IODEV_GPIO),
        bus_rsp_o  => iodev_rsp(IODEV_GPIO),
        port_dir_o => gpio_dir_o,
        port_out_o => gpio_o,
        port_in_i  => gpio_i,
        irq_o      => firq(FIRQ_GPIO)
      );
    end generate;

    neorv32_gpio_disabled:
    if not io_gpio_en_c generate
      iodev_rsp(IODEV_GPIO) <= rsp_terminate_c;
      gpio_dir_o            <= (others => '0');
      gpio_o                <= (others => '0');
      firq(FIRQ_GPIO)       <= '0';
    end generate;

    -- Watch Dog Timer (WDT) ------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_wdt_enabled:
    if IO_WDT_EN generate
      neorv32_wdt_inst: entity neorv32.neorv32_wdt
      port map (
        clk_i      => clk_i,
        rstn_ext_i => rstn_ext,
        rstn_dbg_i => dci_ndmrstn,
        rstn_sys_i => rstn_sys,
        bus_req_i  => iodev_req(IODEV_WDT),
        bus_rsp_o  => iodev_rsp(IODEV_WDT),
        clkgen_i   => clk_gen,
        rstn_o     => rstn_wdt
      );
    end generate;

    neorv32_wdt_disabled:
    if not IO_WDT_EN generate
      iodev_rsp(IODEV_WDT) <= rsp_terminate_c;
      rstn_wdt             <= '1';
    end generate;

    -- Core Local Interruptor (CLINT) ---------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_clint_enabled:
    if IO_CLINT_EN generate
      neorv32_clint_inst: entity neorv32.neorv32_clint
      generic map (
        NUM_HARTS => num_cores_c
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_CLINT),
        bus_rsp_o => iodev_rsp(IODEV_CLINT),
        time_o    => mtime,
        mti_o     => mti,
        msi_o     => msi
      );

      -- synchronize high and low words --
      mtime_sync: process(rstn_i, clk_i)
      begin
        if (rstn_i = '0') then
          mtime_lo(31 downto 0) <= (others => '0');
        elsif rising_edge(clk_i) then
          mtime_lo(31 downto 0) <= mtime(31 downto 0);
        end if;
      end process mtime_sync;
      mtime_time_o <= mtime(63 downto 32) & mtime_lo;
    end generate;

    neorv32_clint_disabled:
    if not IO_CLINT_EN generate
      iodev_rsp(IODEV_CLINT) <= rsp_terminate_c;
      mtime                  <= (others => '0');
      mtime_lo               <= (others => '0');
      mtime_time_o           <= (others => '0');
      mti                    <= (others => irq_mti_i); -- TODO: provide individual top ports for dual-core w/o internal CLINT
      msi                    <= (others => irq_msi_i); -- TODO: provide individual top ports for dual-core w/o internal CLINT
    end generate;

    -- Primary Universal Asynchronous Receiver/Transmitter (UART0) ----------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_uart0_enabled:
    if IO_UART0_EN generate
      neorv32_uart0_inst: entity neorv32.neorv32_uart
      generic map (
        UART_RX_FIFO => IO_UART0_RX_FIFO,
        UART_TX_FIFO => IO_UART0_TX_FIFO
      )
      port map (
        clk_i       => clk_i,
        rstn_i      => rstn_sys,
        bus_req_i   => iodev_req(IODEV_UART0),
        bus_rsp_o   => iodev_rsp(IODEV_UART0),
        clkgen_i    => clk_gen,
        uart_txd_o  => uart0_txd_o,
        uart_rxd_i  => uart0_rxd_i,
        uart_rtsn_o => uart0_rtsn_o,
        uart_ctsn_i => uart0_ctsn_i,
        irq_o       => firq(FIRQ_UART0)
      );
    end generate;

    neorv32_uart0_disabled:
    if not IO_UART0_EN generate
      iodev_rsp(IODEV_UART0) <= rsp_terminate_c;
      uart0_txd_o            <= '0';
      uart0_rtsn_o           <= '1';
      firq(FIRQ_UART0)       <= '0';
    end generate;

    -- Secondary Universal Asynchronous Receiver/Transmitter (UART1) --------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_uart1_enabled:
    if IO_UART1_EN generate
      neorv32_uart1_inst: entity neorv32.neorv32_uart
      generic map (
        UART_RX_FIFO => IO_UART1_RX_FIFO,
        UART_TX_FIFO => IO_UART1_TX_FIFO
      )
      port map (
        clk_i       => clk_i,
        rstn_i      => rstn_sys,
        bus_req_i   => iodev_req(IODEV_UART1),
        bus_rsp_o   => iodev_rsp(IODEV_UART1),
        clkgen_i    => clk_gen,
        uart_txd_o  => uart1_txd_o,
        uart_rxd_i  => uart1_rxd_i,
        uart_rtsn_o => uart1_rtsn_o,
        uart_ctsn_i => uart1_ctsn_i,
        irq_o       => firq(FIRQ_UART1)
      );
    end generate;

    neorv32_uart1_disabled:
    if not IO_UART1_EN generate
      iodev_rsp(IODEV_UART1) <= rsp_terminate_c;
      uart1_txd_o            <= '0';
      uart1_rtsn_o           <= '1';
      firq(FIRQ_UART1)       <= '0';
    end generate;

    -- Serial Peripheral Interface (SPI) ------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_spi_enabled:
    if IO_SPI_EN generate
      neorv32_spi_inst: entity neorv32.neorv32_spi
      generic map (
        IO_SPI_FIFO => IO_SPI_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_SPI),
        bus_rsp_o => iodev_rsp(IODEV_SPI),
        clkgen_i  => clk_gen,
        spi_clk_o => spi_clk_o,
        spi_dat_o => spi_dat_o,
        spi_dat_i => spi_dat_i,
        spi_csn_o => spi_csn_o,
        irq_o     => firq(FIRQ_SPI)
      );
    end generate;

    neorv32_spi_disabled:
    if not IO_SPI_EN generate
      iodev_rsp(IODEV_SPI) <= rsp_terminate_c;
      spi_clk_o            <= '0';
      spi_dat_o            <= '0';
      spi_csn_o            <= (others => '1');
      firq(FIRQ_SPI)       <= '0';
    end generate;

    -- Two-Wire Interface (TWI) ---------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_twi_enabled:
    if IO_TWI_EN generate
      neorv32_twi_inst: entity neorv32.neorv32_twi
      generic map (
        IO_TWI_FIFO => IO_TWI_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_TWI),
        bus_rsp_o => iodev_rsp(IODEV_TWI),
        clkgen_i  => clk_gen,
        twi_sda_i => twi_sda_i,
        twi_sda_o => twi_sda_o,
        twi_scl_i => twi_scl_i,
        twi_scl_o => twi_scl_o,
        irq_o     => firq(FIRQ_TWI)
      );
    end generate;

    neorv32_twi_disabled:
    if not IO_TWI_EN generate
      iodev_rsp(IODEV_TWI) <= rsp_terminate_c;
      twi_sda_o            <= '1';
      twi_scl_o            <= '1';
      firq(FIRQ_TWI)       <= '0';
    end generate;

    -- Two-Wire Device (TWD) ------------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_twd_enabled:
    if IO_TWD_EN generate
      neorv32_twd_inst: entity neorv32.neorv32_twd
      generic map (
        TWD_RX_FIFO => IO_TWD_RX_FIFO,
        TWD_TX_FIFO => IO_TWD_TX_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_TWD),
        bus_rsp_o => iodev_rsp(IODEV_TWD),
        clkgen_i  => clk_gen,
        twd_sda_i => twd_sda_i,
        twd_sda_o => twd_sda_o,
        twd_scl_i => twd_scl_i,
        irq_o     => firq(FIRQ_TWD)
      );
    end generate;

    neorv32_twd_disabled:
    if not IO_TWD_EN generate
      iodev_rsp(IODEV_TWD) <= rsp_terminate_c;
      twd_sda_o            <= '1';
      firq(FIRQ_TWD)       <= '0';
    end generate;

    -- Pulse-Width Modulation Controller (PWM) ------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_pwm_enabled:
    if io_pwm_en_c generate
      neorv32_pwm_inst: entity neorv32.neorv32_pwm
      generic map (
        NUM_CHANNELS => IO_PWM_NUM
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_PWM),
        bus_rsp_o => iodev_rsp(IODEV_PWM),
        clkgen_i  => clk_gen,
        pwm_o     => pwm_o
      );
    end generate;

    neorv32_pwm_disabled:
    if not io_pwm_en_c generate
      iodev_rsp(IODEV_PWM) <= rsp_terminate_c;
      pwm_o                <= (others => '0');
    end generate;

    -- True Random Number Generator (TRNG) ----------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_trng_enabled:
    if IO_TRNG_EN generate
      neorv32_trng_inst: entity neorv32.neorv32_trng
      generic map (
        TRNG_FIFO => IO_TRNG_FIFO,
        NUM_RO    => IO_TRNG_NUM_RO,
        NUM_INV   => IO_TRNG_NUM_INV,
        NUM_RBIT  => IO_TRNG_NUM_RBIT
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_TRNG),
        bus_rsp_o => iodev_rsp(IODEV_TRNG),
        irq_o     => firq(FIRQ_TRNG)
      );
    end generate;

    neorv32_trng_disabled:
    if not IO_TRNG_EN generate
      iodev_rsp(IODEV_TRNG) <= rsp_terminate_c;
      firq(FIRQ_TRNG)       <= '0';
    end generate;

    -- Smart LED (WS2811/WS2812) Interface (NEOLED) -------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_neoled_enabled:
    if IO_NEOLED_EN generate
      neorv32_neoled_inst: entity neorv32.neorv32_neoled
      generic map (
        FIFO_DEPTH => IO_NEOLED_TX_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_NEOLED),
        bus_rsp_o => iodev_rsp(IODEV_NEOLED),
        clkgen_i  => clk_gen,
        irq_o     => firq(FIRQ_NEOLED),
        neoled_o  => neoled_o
      );
    end generate;

    neorv32_neoled_disabled:
    if not IO_NEOLED_EN generate
      iodev_rsp(IODEV_NEOLED) <= rsp_terminate_c;
      firq(FIRQ_NEOLED)       <= '0';
      neoled_o                <= '0';
    end generate;

    -- General Purpose Timer (GPTMR) ----------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_gptmr_enabled:
    if io_gptmr_en_c generate
      neorv32_gptmr_inst: entity neorv32.neorv32_gptmr
      generic map (
        NUM_SLICES => IO_GPTMR_NUM
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_GPTMR),
        bus_rsp_o => iodev_rsp(IODEV_GPTMR),
        clkgen_i  => clk_gen,
        irq_o     => firq(FIRQ_GPTMR)
      );
    end generate;

    neorv32_gptmr_disabled:
    if not io_gptmr_en_c generate
      iodev_rsp(IODEV_GPTMR) <= rsp_terminate_c;
      firq(FIRQ_GPTMR)       <= '0';
    end generate;

    -- 1-Wire Interface Controller (ONEWIRE) --------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_onewire_enabled:
    if IO_ONEWIRE_EN generate
      neorv32_onewire_inst: entity neorv32.neorv32_onewire
      generic map (
        ONEWIRE_FIFO => IO_ONEWIRE_FIFO
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        bus_req_i => iodev_req(IODEV_ONEWIRE),
        bus_rsp_o => iodev_rsp(IODEV_ONEWIRE),
        clkgen_i  => clk_gen,
        onewire_i => onewire_i,
        onewire_o => onewire_o,
        irq_o     => firq(FIRQ_ONEWIRE)
      );
    end generate;

    neorv32_onewire_disabled:
    if not IO_ONEWIRE_EN generate
      iodev_rsp(IODEV_ONEWIRE) <= rsp_terminate_c;
      onewire_o                <= '1';
      firq(FIRQ_ONEWIRE)       <= '0';
    end generate;

    -- Stream Link Interface (SLINK) ----------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_slink_enabled:
    if IO_SLINK_EN generate
      neorv32_slink_inst: entity neorv32.neorv32_slink
      generic map (
        SLINK_RX_FIFO => IO_SLINK_RX_FIFO,
        SLINK_TX_FIFO => IO_SLINK_TX_FIFO
      )
      port map (
        clk_i            => clk_i,
        rstn_i           => rstn_sys,
        bus_req_i        => iodev_req(IODEV_SLINK),
        bus_rsp_o        => iodev_rsp(IODEV_SLINK),
        irq_o            => firq(FIRQ_SLINK),
        slink_rx_data_i  => slink_rx_dat_i,
        slink_rx_src_i   => slink_rx_src_i,
        slink_rx_valid_i => slink_rx_val_i,
        slink_rx_last_i  => slink_rx_lst_i,
        slink_rx_ready_o => slink_rx_rdy_o,
        slink_tx_data_o  => slink_tx_dat_o,
        slink_tx_dst_o   => slink_tx_dst_o,
        slink_tx_valid_o => slink_tx_val_o,
        slink_tx_last_o  => slink_tx_lst_o,
        slink_tx_ready_i => slink_tx_rdy_i
      );
    end generate;

    neorv32_slink_disabled:
    if not IO_SLINK_EN generate
      iodev_rsp(IODEV_SLINK) <= rsp_terminate_c;
      firq(FIRQ_SLINK)       <= '0';
      slink_rx_rdy_o         <= '0';
      slink_tx_dat_o         <= (others => '0');
      slink_tx_dst_o         <= (others => '0');
      slink_tx_val_o         <= '0';
      slink_tx_lst_o         <= '0';
    end generate;

    -- Execution Tracer (TRACER) --------------------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_tracer_enabled:
    if IO_TRACER_EN generate
      neorv32_tracer_inst: entity neorv32.neorv32_tracer
      generic map (
        TRACE_DEPTH   => IO_TRACER_BUFFER,
        DUAL_CORE_EN  => DUAL_CORE_EN,
        SIM_LOG_EN    => IO_TRACER_SIMLOG_EN,
        SIM_LOG_FILE0 => "neorv32.tracer0.log",
        SIM_LOG_FILE1 => "neorv32.tracer1.log"
      )
      port map (
        clk_i     => clk_i,
        rstn_i    => rstn_sys,
        trace0_i  => cpu_trace(cpu_trace'left),
        trace1_i  => cpu_trace(cpu_trace'right),
        bus_req_i => iodev_req(IODEV_TRACER),
        bus_rsp_o => iodev_rsp(IODEV_TRACER),
        irq_o     => firq(FIRQ_TRACER)
      );
    end generate;

    neorv32_tracer_disabled:
    if not IO_TRACER_EN generate
      iodev_rsp(IODEV_TRACER) <= rsp_terminate_c;
      firq(FIRQ_TRACER)       <= '0';
    end generate;

    -- System Configuration Information Memory (SYSINFO) --------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_sysinfo_inst: entity neorv32.neorv32_sysinfo
    generic map (
      BUS_TMO_INT       => int_bus_tmo_c,
      BUS_TMO_EXT       => XBUS_TIMEOUT,
      NUM_HARTS         => num_cores_c,
      CLOCK_FREQUENCY   => CLOCK_FREQUENCY,
      BOOT_MODE_SELECT  => BOOT_MODE_SELECT,
      INT_BOOTLOADER_EN => bootrom_en_c,
      IMEM_EN           => IMEM_EN,
      IMEM_ROM          => imem_as_rom_c,
      IMEM_SIZE         => imem_size_c,
      DMEM_EN           => DMEM_EN,
      DMEM_SIZE         => dmem_size_c,
      ICACHE_EN         => ICACHE_EN,
      ICACHE_NUM_BLOCKS => ICACHE_NUM_BLOCKS,
      DCACHE_EN         => DCACHE_EN,
      DCACHE_NUM_BLOCKS => DCACHE_NUM_BLOCKS,
      CACHE_BLOCK_SIZE  => CACHE_BLOCK_SIZE,
      CACHE_BURSTS_EN   => bursts_en_c,
      CACHE_UC_BASE     => CACHE_UC_BASE(31 downto 28),
      SMC_EN            => SMC_EN,
      XBUS_EN           => XBUS_EN,
      OCD_EN            => OCD_EN,
      OCD_AUTH          => ocd_auth_en_c,
      IO_GPIO_EN        => io_gpio_en_c,
      IO_CLINT_EN       => IO_CLINT_EN,
      IO_UART0_EN       => IO_UART0_EN,
      IO_UART1_EN       => IO_UART1_EN,
      IO_SPI_EN         => IO_SPI_EN,
      IO_SDI_EN         => IO_SDI_EN,
      IO_TWI_EN         => IO_TWI_EN,
      IO_TWD_EN         => IO_TWD_EN,
      IO_PWM_EN         => io_pwm_en_c,
      IO_WDT_EN         => IO_WDT_EN,
      IO_TRNG_EN        => IO_TRNG_EN,
      IO_CFS_EN         => IO_CFS_EN,
      IO_NEOLED_EN      => IO_NEOLED_EN,
      IO_GPTMR_EN       => io_gptmr_en_c,
      IO_ONEWIRE_EN     => IO_ONEWIRE_EN,
      IO_DMA_EN         => IO_DMA_EN,
      IO_SLINK_EN       => IO_SLINK_EN,
      IO_TRACER_EN      => IO_TRACER_EN
    )
    port map (
      clk_i     => clk_i,
      rstn_i    => rstn_sys,
      bus_req_i => iodev_req(IODEV_SYSINFO),
      bus_rsp_o => iodev_rsp(IODEV_SYSINFO)
    );

  end generate;

  -- **************************************************************************************************************************
  -- On-Chip Debugger Complex
  -- **************************************************************************************************************************

  neorv32_ocd_enabled:
  if OCD_EN generate

    -- On-Chip Debugger - Debug Transport Module (DTM) ----------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_debug_dtm_inst: entity neorv32.neorv32_debug_dtm
    generic map (
      IDCODE_VERSION => (others => '0'), -- yet unused
      IDCODE_PARTID  => (others => '0'), -- yet unused
      IDCODE_MANID   => OCD_JEDEC_ID
    )
    port map (
      clk_i      => clk_i,
      rstn_i     => rstn_ext,
      jtag_tck_i => jtag_tck_i,
      jtag_tdi_i => jtag_tdi_i,
      jtag_tdo_o => jtag_tdo_o,
      jtag_tms_i => jtag_tms_i,
      dmi_req_o  => dmi_req,
      dmi_rsp_i  => dmi_rsp
    );

    -- On-Chip Debugger - Debug Module (DM) ---------------------------------------------------
    -- -------------------------------------------------------------------------------------------
    neorv32_debug_dm_inst: entity neorv32.neorv32_debug_dm
    generic map (
      NUM_HARTS     => num_cores_c,
      AUTHENTICATOR => ocd_auth_en_c
    )
    port map (
      clk_i      => clk_i,
      rstn_i     => rstn_ext,
      dmi_req_i  => dmi_req,
      dmi_rsp_o  => dmi_rsp,
      bus_req_i  => iodev_req(IODEV_OCD),
      bus_rsp_o  => iodev_rsp(IODEV_OCD),
      ndmrstn_o  => dci_ndmrstn,
      halt_req_o => dci_haltreq
    );

  end generate; -- /neorv32_ocd_enabled

  neorv32_debug_ocd_disabled:
  if not OCD_EN generate
    iodev_rsp(IODEV_OCD) <= rsp_terminate_c;
    dmi_req              <= dmi_req_terminate_c;
    dmi_rsp              <= dmi_rsp_terminate_c;
    jtag_tdo_o           <= jtag_tdi_i; -- JTAG pass-through
    dci_ndmrstn          <= '1';
    dci_haltreq          <= (others => '0');
  end generate;

end neorv32_top_rtl;
