455 lines
27 KiB
VHDL
455 lines
27 KiB
VHDL
-- #################################################################################################
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-- # << NEORV32 - CPU Top Entity >> #
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-- # ********************************************************************************************* #
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-- # Check out the CPU's online documentation for more information: #
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-- # HQ: https://github.com/stnolting/neorv32 #
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-- # Data Sheet: https://stnolting.github.io/neorv32 #
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-- # User Guide: https://stnolting.github.io/neorv32/ug #
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-- # ********************************************************************************************* #
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-- # BSD 3-Clause License #
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-- # #
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-- # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
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-- # #
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-- # Redistribution and use in source and binary forms, with or without modification, are #
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-- # permitted provided that the following conditions are met: #
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-- # #
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-- # 1. Redistributions of source code must retain the above copyright notice, this list of #
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-- # conditions and the following disclaimer. #
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-- # #
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-- # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
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-- # conditions and the following disclaimer in the documentation and/or other materials #
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-- # provided with the distribution. #
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-- # #
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-- # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
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-- # endorse or promote products derived from this software without specific prior written #
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-- # permission. #
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-- # #
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-- # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
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-- # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
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-- # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
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-- # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
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-- # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
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-- # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
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-- # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
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-- # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
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-- # OF THE POSSIBILITY OF SUCH DAMAGE. #
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-- # ********************************************************************************************* #
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-- # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
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-- #################################################################################################
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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library neorv32;
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use neorv32.neorv32_package.all;
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entity neorv32_cpu is
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generic (
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-- General --
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HW_THREAD_ID : natural; -- hardware thread id (32-bit)
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CPU_BOOT_ADDR : std_ulogic_vector(31 downto 0); -- cpu boot address
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CPU_DEBUG_PARK_ADDR : std_ulogic_vector(31 downto 0); -- cpu debug mode parking loop entry address
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CPU_DEBUG_EXC_ADDR : std_ulogic_vector(31 downto 0); -- cpu debug mode exception entry address
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-- RISC-V CPU Extensions --
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CPU_EXTENSION_RISCV_B : boolean; -- implement bit-manipulation extension?
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CPU_EXTENSION_RISCV_C : boolean; -- implement compressed extension?
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CPU_EXTENSION_RISCV_E : boolean; -- implement embedded RF extension?
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CPU_EXTENSION_RISCV_M : boolean; -- implement mul/div extension?
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CPU_EXTENSION_RISCV_U : boolean; -- implement user mode extension?
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CPU_EXTENSION_RISCV_Zfinx : boolean; -- implement 32-bit floating-point extension (using INT reg!)
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CPU_EXTENSION_RISCV_Zicsr : boolean; -- implement CSR system?
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CPU_EXTENSION_RISCV_Zicntr : boolean; -- implement base counters?
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CPU_EXTENSION_RISCV_Zihpm : boolean; -- implement hardware performance monitors?
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CPU_EXTENSION_RISCV_Zifencei : boolean; -- implement instruction stream sync.?
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CPU_EXTENSION_RISCV_Zmmul : boolean; -- implement multiply-only M sub-extension?
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CPU_EXTENSION_RISCV_Zxcfu : boolean; -- implement custom (instr.) functions unit?
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CPU_EXTENSION_RISCV_Sdext : boolean; -- implement external debug mode extension?
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CPU_EXTENSION_RISCV_Sdtrig : boolean; -- implement trigger module extension?
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-- Extension Options --
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FAST_MUL_EN : boolean; -- use DSPs for M extension's multiplier
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FAST_SHIFT_EN : boolean; -- use barrel shifter for shift operations
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CPU_IPB_ENTRIES : natural; -- entries in instruction prefetch buffer, has to be a power of 2, min 1
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-- Physical Memory Protection (PMP) --
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PMP_NUM_REGIONS : natural; -- number of regions (0..16)
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PMP_MIN_GRANULARITY : natural; -- minimal region granularity in bytes, has to be a power of 2, min 4 bytes
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-- Hardware Performance Monitors (HPM) --
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HPM_NUM_CNTS : natural; -- number of implemented HPM counters (0..29)
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HPM_CNT_WIDTH : natural -- total size of HPM counters (0..64)
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);
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port (
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-- global control --
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clk_i : in std_ulogic; -- global clock, rising edge
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rstn_i : in std_ulogic; -- global reset, low-active, async
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sleep_o : out std_ulogic; -- cpu is in sleep mode when set
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debug_o : out std_ulogic; -- cpu is in debug mode when set
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-- instruction bus interface --
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i_bus_addr_o : out std_ulogic_vector(31 downto 0); -- bus access address
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i_bus_rdata_i : in std_ulogic_vector(31 downto 0); -- bus read data
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i_bus_re_o : out std_ulogic; -- read request
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i_bus_ack_i : in std_ulogic; -- bus transfer acknowledge
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i_bus_err_i : in std_ulogic; -- bus transfer error
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i_bus_fence_o : out std_ulogic; -- executed FENCEI operation
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i_bus_priv_o : out std_ulogic; -- current effective privilege level
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-- data bus interface --
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d_bus_addr_o : out std_ulogic_vector(31 downto 0); -- bus access address
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d_bus_rdata_i : in std_ulogic_vector(31 downto 0); -- bus read data
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d_bus_wdata_o : out std_ulogic_vector(31 downto 0); -- bus write data
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d_bus_ben_o : out std_ulogic_vector(3 downto 0); -- byte enable
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d_bus_we_o : out std_ulogic; -- write request
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d_bus_re_o : out std_ulogic; -- read request
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d_bus_ack_i : in std_ulogic; -- bus transfer acknowledge
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d_bus_err_i : in std_ulogic; -- bus transfer error
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d_bus_fence_o : out std_ulogic; -- executed FENCE operation
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d_bus_priv_o : out std_ulogic; -- current effective privilege level
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-- interrupts (risc-v compliant) --
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msw_irq_i : in std_ulogic;-- machine software interrupt
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mext_irq_i : in std_ulogic;-- machine external interrupt
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mtime_irq_i : in std_ulogic;-- machine timer interrupt
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-- fast interrupts (custom) --
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firq_i : in std_ulogic_vector(15 downto 0);
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-- debug mode (halt) request --
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db_halt_req_i : in std_ulogic
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);
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end neorv32_cpu;
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architecture neorv32_cpu_rtl of neorv32_cpu is
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-- RV64: WORK IN PROGRESS -----------------------------------------------------------------------
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-- not available as CPU generic as rv64 ISA extension is not (fully) supported yet!
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constant XLEN : natural := 32; -- data path width
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-- ----------------------------------------------------------------------------------------------
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-- local constants: additional register file read ports --
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constant regfile_rs3_en_c : boolean := CPU_EXTENSION_RISCV_Zxcfu or CPU_EXTENSION_RISCV_Zfinx; -- 3rd register file read port (rs3)
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constant regfile_rs4_en_c : boolean := CPU_EXTENSION_RISCV_Zxcfu; -- 4th register file read port (rs4)
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-- local constant: instruction prefetch buffer depth --
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constant ipb_override_c : boolean := (CPU_EXTENSION_RISCV_C = true) and (CPU_IPB_ENTRIES < 2); -- override IPB size: set to 2?
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constant ipb_depth_c : natural := cond_sel_natural_f(ipb_override_c, 2, CPU_IPB_ENTRIES);
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-- local signals --
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signal ctrl : std_ulogic_vector(ctrl_width_c-1 downto 0); -- main control bus
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signal imm : std_ulogic_vector(XLEN-1 downto 0); -- immediate
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signal rs1 : std_ulogic_vector(XLEN-1 downto 0); -- source register 1
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signal rs2 : std_ulogic_vector(XLEN-1 downto 0); -- source register 2
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signal rs3 : std_ulogic_vector(XLEN-1 downto 0); -- source register 3
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signal rs4 : std_ulogic_vector(XLEN-1 downto 0); -- source register 4
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signal alu_res : std_ulogic_vector(XLEN-1 downto 0); -- alu result
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signal alu_add : std_ulogic_vector(XLEN-1 downto 0); -- alu address result
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signal alu_cmp : std_ulogic_vector(1 downto 0); -- comparator result
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signal mem_rdata : std_ulogic_vector(XLEN-1 downto 0); -- memory read data
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signal alu_idone : std_ulogic; -- iterative alu operation done
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signal bus_d_wait : std_ulogic; -- wait for current bus data access
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signal csr_rdata : std_ulogic_vector(XLEN-1 downto 0); -- csr read data
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signal mar : std_ulogic_vector(XLEN-1 downto 0); -- current memory address register
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signal ma_load : std_ulogic; -- misaligned load data address
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signal ma_store : std_ulogic; -- misaligned store data address
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signal be_load : std_ulogic; -- bus error on load data access
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signal be_store : std_ulogic; -- bus error on store data access
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signal fetch_pc : std_ulogic_vector(XLEN-1 downto 0); -- pc for instruction fetch
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signal curr_pc : std_ulogic_vector(XLEN-1 downto 0); -- current pc (for current executed instruction)
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signal next_pc : std_ulogic_vector(XLEN-1 downto 0); -- next pc (for next executed instruction)
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signal fpu_flags : std_ulogic_vector(4 downto 0); -- FPU exception flags
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signal i_pmp_fault : std_ulogic; -- instruction fetch PMP fault
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-- pmp interface --
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signal pmp_addr : pmp_addr_if_t;
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signal pmp_ctrl : pmp_ctrl_if_t;
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begin
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-- Sanity Checks --------------------------------------------------------------------------
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-- -------------------------------------------------------------------------------------------
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-- say hello --
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assert false report "The NEORV32 RISC-V Processor - github.com/stnolting/neorv32" severity note;
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-- CPU ISA configuration --
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assert false report
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"NEORV32 CPU CONFIG NOTE: Core ISA ('MARCH') = RV32" &
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cond_sel_string_f(CPU_EXTENSION_RISCV_E, "E", "I") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_M, "M", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_C, "C", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_B, "B", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_U, "U", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zicsr, "_Zicsr", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zicntr, "_Zicntr", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zihpm, "_Zihpm", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zifencei, "_Zifencei", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zfinx, "_Zfinx", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zmmul, "_Zmmul", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Zxcfu, "_Zxcfu", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Sdext, "_Sdext", "") &
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cond_sel_string_f(CPU_EXTENSION_RISCV_Sdtrig, "_Sdtrig", "") &
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""
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severity note;
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-- simulation notifier --
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assert not (is_simulation_c = true) report
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"NEORV32 CPU WARNING! Assuming this is a simulation." severity warning;
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assert not (is_simulation_c = false) report
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"NEORV32 CPU NOTE: Assuming this is real hardware." severity note;
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-- native data width check (work in progress!) --
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assert not (XLEN /= 32) report
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"NEORV32 CPU CONFIG ERROR! <XLEN> native data path width has to be 32 (bit)." severity error;
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-- CPU boot address --
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assert not (CPU_BOOT_ADDR(1 downto 0) /= "00") report
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"NEORV32 CPU CONFIG ERROR! <CPU_BOOT_ADDR> has to be 32-bit aligned." severity error;
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assert false report
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"NEORV32 CPU CONFIG NOTE: Boot from address 0x" & to_hstring32_f(CPU_BOOT_ADDR) & "." severity note;
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-- CSR system --
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assert not (CPU_EXTENSION_RISCV_Zicsr = false) report
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"NEORV32 CPU CONFIG WARNING! No exception/interrupt/trap/privileged features available when <CPU_EXTENSION_RISCV_Zicsr> = false." severity warning;
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-- U-extension requires Zicsr extension --
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assert not ((CPU_EXTENSION_RISCV_Zicsr = false) and (CPU_EXTENSION_RISCV_U = true)) report
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"NEORV32 CPU CONFIG ERROR! User mode requires <CPU_EXTENSION_RISCV_Zicsr> extension to be enabled." severity error;
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-- Instruction prefetch buffer --
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assert not (is_power_of_two_f(CPU_IPB_ENTRIES) = false) report
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"NEORV32 CPU CONFIG ERROR! Number of entries in instruction prefetch buffer <CPU_IPB_ENTRIES> has to be a power of two." severity error;
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assert not (ipb_override_c = true) report
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"NEORV32 CPU CONFIG WARNING! Overriding <CPU_IPB_ENTRIES> configuration (setting =2) because C ISA extension is enabled." severity warning;
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-- PMP --
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assert not (PMP_NUM_REGIONS > 0) report
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"NEORV32 CPU CONFIG NOTE: Implementing " & positive'image(PMP_NUM_REGIONS) & " PMP regions." severity note;
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assert not (PMP_NUM_REGIONS > 16) report
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"NEORV32 CPU CONFIG ERROR! Number of PMP regions <PMP_NUM_REGIONS> out of valid range (0..16)." severity error;
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assert not ((is_power_of_two_f(PMP_MIN_GRANULARITY) = false) and (PMP_NUM_REGIONS > 0)) report
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"NEORV32 CPU CONFIG ERROR! <PMP_MIN_GRANULARITY> has to be a power of two." severity error;
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assert not (PMP_MIN_GRANULARITY < 4) report
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"NEORV32 CPU CONFIG ERROR! <PMP_MIN_GRANULARITY> has to be >= 4 bytes." severity error;
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assert not ((CPU_EXTENSION_RISCV_Zicsr = false) and (PMP_NUM_REGIONS > 0)) report
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"NEORV32 CPU CONFIG ERROR! Physical memory protection (PMP) requires <CPU_EXTENSION_RISCV_Zicsr> extension to be enabled." severity error;
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-- HPM counters --
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assert not ((CPU_EXTENSION_RISCV_Zihpm = true) and (HPM_NUM_CNTS > 0)) report
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"NEORV32 CPU CONFIG NOTE: Implementing " & positive'image(HPM_NUM_CNTS) & " HPM counters." severity note;
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assert not ((CPU_EXTENSION_RISCV_Zihpm = true) and (HPM_NUM_CNTS > 29)) report
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"NEORV32 CPU CONFIG ERROR! Number of HPM counters <HPM_NUM_CNTS> out of valid range (0..29)." severity error;
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assert not ((CPU_EXTENSION_RISCV_Zihpm = true) and ((HPM_CNT_WIDTH < 0) or (HPM_CNT_WIDTH > 64))) report
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"NEORV32 CPU CONFIG ERROR! HPM counter width <HPM_CNT_WIDTH> has to be 0..64 bit." severity error;
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assert not ((CPU_EXTENSION_RISCV_Zicsr = false) and (CPU_EXTENSION_RISCV_Zihpm = true)) report
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"NEORV32 CPU CONFIG ERROR! Hardware performance monitors extension <CPU_EXTENSION_RISCV_Zihpm> requires <CPU_EXTENSION_RISCV_Zicsr> extension to be enabled." severity error;
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-- Mul-extension(s) --
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assert not ((CPU_EXTENSION_RISCV_Zmmul = true) and (CPU_EXTENSION_RISCV_M = true)) report
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"NEORV32 CPU CONFIG ERROR! <M> and <Zmmul> extensions cannot co-exist!" severity error;
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-- Debug mode --
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assert not ((CPU_EXTENSION_RISCV_Sdext = true) and (CPU_EXTENSION_RISCV_Zicsr = false)) report
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"NEORV32 CPU CONFIG ERROR! Debug mode requires <CPU_EXTENSION_RISCV_Zicsr> extension to be enabled." severity error;
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assert not ((CPU_EXTENSION_RISCV_Sdext = true) and (CPU_EXTENSION_RISCV_Zifencei = false)) report
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"NEORV32 CPU CONFIG ERROR! Debug mode requires <CPU_EXTENSION_RISCV_Zifencei> extension to be enabled." severity error;
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-- fast multiplication option --
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assert not (FAST_MUL_EN = true) report
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"NEORV32 CPU CONFIG NOTE: <FAST_MUL_EN> enabled. Trying to infer DSP blocks for multiplications." severity note;
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-- fast shift option --
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assert not (FAST_SHIFT_EN = true) report
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"NEORV32 CPU CONFIG NOTE: <FAST_SHIFT_EN> enabled. Implementing full-parallel logic / barrel shifters." severity note;
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-- Control Unit ---------------------------------------------------------------------------
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-- -------------------------------------------------------------------------------------------
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neorv32_cpu_control_inst: neorv32_cpu_control
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generic map (
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-- General --
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XLEN => XLEN, -- data path width
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HW_THREAD_ID => HW_THREAD_ID, -- hardware thread id
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CPU_BOOT_ADDR => CPU_BOOT_ADDR, -- cpu boot address
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CPU_DEBUG_PARK_ADDR => CPU_DEBUG_PARK_ADDR, -- cpu debug mode parking loop entry address
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CPU_DEBUG_EXC_ADDR => CPU_DEBUG_EXC_ADDR, -- cpu debug mode exception entry address
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-- RISC-V CPU Extensions --
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CPU_EXTENSION_RISCV_B => CPU_EXTENSION_RISCV_B, -- implement bit-manipulation extension?
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CPU_EXTENSION_RISCV_C => CPU_EXTENSION_RISCV_C, -- implement compressed extension?
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CPU_EXTENSION_RISCV_E => CPU_EXTENSION_RISCV_E, -- implement embedded RF extension?
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CPU_EXTENSION_RISCV_M => CPU_EXTENSION_RISCV_M, -- implement mul/div extension?
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CPU_EXTENSION_RISCV_U => CPU_EXTENSION_RISCV_U, -- implement user mode extension?
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CPU_EXTENSION_RISCV_Zfinx => CPU_EXTENSION_RISCV_Zfinx, -- implement 32-bit floating-point extension (using INT reg!)
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CPU_EXTENSION_RISCV_Zicsr => CPU_EXTENSION_RISCV_Zicsr, -- implement CSR system?
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CPU_EXTENSION_RISCV_Zicntr => CPU_EXTENSION_RISCV_Zicntr, -- implement base counters?
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CPU_EXTENSION_RISCV_Zihpm => CPU_EXTENSION_RISCV_Zihpm, -- implement hardware performance monitors?
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CPU_EXTENSION_RISCV_Zifencei => CPU_EXTENSION_RISCV_Zifencei, -- implement instruction stream sync.?
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CPU_EXTENSION_RISCV_Zmmul => CPU_EXTENSION_RISCV_Zmmul, -- implement multiply-only M sub-extension?
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CPU_EXTENSION_RISCV_Zxcfu => CPU_EXTENSION_RISCV_Zxcfu, -- implement custom (instr.) functions unit?
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CPU_EXTENSION_RISCV_Sdext => CPU_EXTENSION_RISCV_Sdext, -- implement external debug mode extension?
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CPU_EXTENSION_RISCV_Sdtrig => CPU_EXTENSION_RISCV_Sdtrig, -- implement trigger module extension?
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-- Tuning Options --
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FAST_MUL_EN => FAST_MUL_EN, -- use DSPs for M extension's multiplier
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FAST_SHIFT_EN => FAST_SHIFT_EN, -- use barrel shifter for shift operations
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CPU_IPB_ENTRIES => ipb_depth_c, -- entries is instruction prefetch buffer, has to be a power of 2, min 1
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-- Physical memory protection (PMP) --
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PMP_NUM_REGIONS => PMP_NUM_REGIONS, -- number of regions (0..16)
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PMP_MIN_GRANULARITY => PMP_MIN_GRANULARITY, -- minimal region granularity in bytes, has to be a power of 2, min 4 bytes
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-- Hardware Performance Monitors (HPM) --
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HPM_NUM_CNTS => HPM_NUM_CNTS, -- number of implemented HPM counters (0..29)
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HPM_CNT_WIDTH => HPM_CNT_WIDTH -- total size of HPM counters
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)
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port map (
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-- global control --
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clk_i => clk_i, -- global clock, rising edge
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rstn_i => rstn_i, -- global reset, low-active, async
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ctrl_o => ctrl, -- main control bus
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-- instruction fetch interface --
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i_bus_addr_o => fetch_pc, -- bus access address
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i_bus_rdata_i => i_bus_rdata_i, -- bus read data
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i_bus_re_o => i_bus_re_o, -- read enable
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i_bus_ack_i => i_bus_ack_i, -- bus transfer acknowledge
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i_bus_err_i => i_bus_err_i, -- bus transfer error
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i_pmp_fault_i => i_pmp_fault, -- instruction fetch pmp fault
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-- status input --
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alu_idone_i => alu_idone, -- ALU iterative operation done
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bus_d_wait_i => bus_d_wait, -- wait for bus
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-- data input --
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cmp_i => alu_cmp, -- comparator status
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alu_add_i => alu_add, -- ALU address result
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rs1_i => rs1, -- rf source 1
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-- data output --
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imm_o => imm, -- immediate
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curr_pc_o => curr_pc, -- current PC (corresponding to current instruction)
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next_pc_o => next_pc, -- next PC (corresponding to next instruction)
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csr_rdata_o => csr_rdata, -- CSR read data
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-- FPU interface --
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fpu_flags_i => fpu_flags, -- exception flags
|
|
-- debug mode (halt) request --
|
|
db_halt_req_i => db_halt_req_i,
|
|
-- interrupts (risc-v compliant) --
|
|
msw_irq_i => msw_irq_i, -- machine software interrupt
|
|
mext_irq_i => mext_irq_i, -- machine external interrupt
|
|
mtime_irq_i => mtime_irq_i, -- machine timer interrupt
|
|
-- fast interrupts (custom) --
|
|
firq_i => firq_i, -- fast interrupt trigger
|
|
-- physical memory protection --
|
|
pmp_addr_o => pmp_addr, -- addresses
|
|
pmp_ctrl_o => pmp_ctrl, -- configs
|
|
-- bus access exceptions --
|
|
mar_i => mar, -- memory address register
|
|
ma_load_i => ma_load, -- misaligned load data address
|
|
ma_store_i => ma_store, -- misaligned store data address
|
|
be_load_i => be_load, -- bus error on load data access
|
|
be_store_i => be_store -- bus error on store data access
|
|
);
|
|
|
|
-- CPU state --
|
|
sleep_o <= ctrl(ctrl_sleep_c); -- set when CPU is sleeping (after WFI)
|
|
debug_o <= ctrl(ctrl_debug_running_c); -- set when CPU is in debug mode
|
|
|
|
-- instruction fetch interface --
|
|
i_bus_addr_o <= fetch_pc;
|
|
i_bus_fence_o <= ctrl(ctrl_bus_fencei_c);
|
|
i_bus_priv_o <= ctrl(ctrl_priv_mode_c);
|
|
|
|
|
|
-- Register File --------------------------------------------------------------------------
|
|
-- -------------------------------------------------------------------------------------------
|
|
neorv32_cpu_regfile_inst: neorv32_cpu_regfile
|
|
generic map (
|
|
XLEN => XLEN, -- data path width
|
|
CPU_EXTENSION_RISCV_E => CPU_EXTENSION_RISCV_E, -- implement embedded RF extension?
|
|
RS3_EN => regfile_rs3_en_c, -- enable 3rd read port
|
|
RS4_EN => regfile_rs4_en_c -- enable 4th read port
|
|
)
|
|
port map (
|
|
-- global control --
|
|
clk_i => clk_i, -- global clock, rising edge
|
|
ctrl_i => ctrl, -- main control bus
|
|
-- data input --
|
|
alu_i => alu_res, -- ALU result
|
|
mem_i => mem_rdata, -- memory read data
|
|
csr_i => csr_rdata, -- CSR read data
|
|
pc2_i => next_pc, -- next PC
|
|
-- data output --
|
|
rs1_o => rs1, -- operand 1
|
|
rs2_o => rs2, -- operand 2
|
|
rs3_o => rs3, -- operand 3
|
|
rs4_o => rs4 -- operand 4
|
|
);
|
|
|
|
|
|
-- ALU ------------------------------------------------------------------------------------
|
|
-- -------------------------------------------------------------------------------------------
|
|
neorv32_cpu_alu_inst: neorv32_cpu_alu
|
|
generic map (
|
|
XLEN => XLEN, -- data path width
|
|
-- RISC-V CPU Extensions --
|
|
CPU_EXTENSION_RISCV_B => CPU_EXTENSION_RISCV_B, -- implement bit-manipulation extension?
|
|
CPU_EXTENSION_RISCV_M => CPU_EXTENSION_RISCV_M, -- implement mul/div extension?
|
|
CPU_EXTENSION_RISCV_Zmmul => CPU_EXTENSION_RISCV_Zmmul, -- implement multiply-only M sub-extension?
|
|
CPU_EXTENSION_RISCV_Zfinx => CPU_EXTENSION_RISCV_Zfinx, -- implement 32-bit floating-point extension (using INT reg!)
|
|
CPU_EXTENSION_RISCV_Zxcfu => CPU_EXTENSION_RISCV_Zxcfu, -- implement custom (instr.) functions unit?
|
|
-- Extension Options --
|
|
FAST_MUL_EN => FAST_MUL_EN, -- use DSPs for M extension's multiplier
|
|
FAST_SHIFT_EN => FAST_SHIFT_EN -- use barrel shifter for shift operations
|
|
)
|
|
port map (
|
|
-- global control --
|
|
clk_i => clk_i, -- global clock, rising edge
|
|
rstn_i => rstn_i, -- global reset, low-active, async
|
|
ctrl_i => ctrl, -- main control bus
|
|
-- data input --
|
|
rs1_i => rs1, -- rf source 1
|
|
rs2_i => rs2, -- rf source 2
|
|
rs3_i => rs3, -- rf source 3
|
|
rs4_i => rs4, -- rf source 4
|
|
pc_i => curr_pc, -- current PC
|
|
imm_i => imm, -- immediate
|
|
-- data output --
|
|
cmp_o => alu_cmp, -- comparator status
|
|
res_o => alu_res, -- ALU result
|
|
add_o => alu_add, -- address computation result
|
|
fpu_flags_o => fpu_flags, -- FPU exception flags
|
|
-- status --
|
|
idone_o => alu_idone -- iterative processing units done?
|
|
);
|
|
|
|
|
|
-- Bus Interface (Load/Store Unit) --------------------------------------------------------
|
|
-- -------------------------------------------------------------------------------------------
|
|
neorv32_cpu_bus_inst: neorv32_cpu_bus
|
|
generic map (
|
|
XLEN => XLEN, -- data path width
|
|
PMP_NUM_REGIONS => PMP_NUM_REGIONS, -- number of regions (0..16)
|
|
PMP_MIN_GRANULARITY => PMP_MIN_GRANULARITY -- minimal region granularity in bytes, has to be a power of 2, min 4 bytes
|
|
)
|
|
port map (
|
|
-- global control --
|
|
clk_i => clk_i, -- global clock, rising edge
|
|
rstn_i => rstn_i, -- global reset, low-active, async
|
|
ctrl_i => ctrl, -- main control bus
|
|
-- cpu instruction fetch interface --
|
|
fetch_pc_i => fetch_pc, -- PC for instruction fetch
|
|
i_pmp_fault_o => i_pmp_fault, -- instruction fetch pmp fault
|
|
-- cpu data access interface --
|
|
addr_i => alu_add, -- ALU.add result -> access address
|
|
wdata_i => rs2, -- write data
|
|
rdata_o => mem_rdata, -- read data
|
|
mar_o => mar, -- current memory address register
|
|
d_wait_o => bus_d_wait, -- wait for access to complete
|
|
ma_load_o => ma_load, -- misaligned load data address
|
|
ma_store_o => ma_store, -- misaligned store data address
|
|
be_load_o => be_load, -- bus error on load data access
|
|
be_store_o => be_store, -- bus error on store data access
|
|
-- physical memory protection --
|
|
pmp_addr_i => pmp_addr, -- addresses
|
|
pmp_ctrl_i => pmp_ctrl, -- configurations
|
|
-- data bus --
|
|
d_bus_addr_o => d_bus_addr_o, -- bus access address
|
|
d_bus_rdata_i => d_bus_rdata_i, -- bus read data
|
|
d_bus_wdata_o => d_bus_wdata_o, -- bus write data
|
|
d_bus_ben_o => d_bus_ben_o, -- byte enable
|
|
d_bus_we_o => d_bus_we_o, -- write enable
|
|
d_bus_re_o => d_bus_re_o, -- read enable
|
|
d_bus_ack_i => d_bus_ack_i, -- bus transfer acknowledge
|
|
d_bus_err_i => d_bus_err_i, -- bus transfer error
|
|
d_bus_fence_o => d_bus_fence_o, -- fence operation
|
|
d_bus_priv_o => d_bus_priv_o -- current effective privilege level
|
|
);
|
|
|
|
|
|
end neorv32_cpu_rtl;
|