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SEm-Labos/Libs/RiscV_test/NEORV32_test/simple/neorv32_tb.simple.vhd

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2024-02-23 13:01:05 +00:00
-- #################################################################################################
-- # << NEORV32 - Default Processor Testbench >> #
-- # ********************************************************************************************* #
-- # The processor is configured to use a maximum of functional units (for testing purpose). #
-- # Use the "User Configuration" section to configure the testbench according to your needs. #
-- # See NEORV32 data sheet for more information. #
-- # ********************************************************************************************* #
-- # BSD 3-Clause License #
-- # #
-- # Copyright (c) 2021, Stephan Nolting. All rights reserved. #
-- # #
-- # Redistribution and use in source and binary forms, with or without modification, are #
-- # permitted provided that the following conditions are met: #
-- # #
-- # 1. Redistributions of source code must retain the above copyright notice, this list of #
-- # conditions and the following disclaimer. #
-- # #
-- # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
-- # conditions and the following disclaimer in the documentation and/or other materials #
-- # provided with the distribution. #
-- # #
-- # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
-- # endorse or promote products derived from this software without specific prior written #
-- # permission. #
-- # #
-- # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
-- # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
-- # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
-- # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
-- # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
-- # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
-- # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
-- # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
-- # OF THE POSSIBILITY OF SUCH DAMAGE. #
-- # ********************************************************************************************* #
-- # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
-- #################################################################################################
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use ieee.math_real.all;
library neorv32;
use neorv32.neorv32_package.all;
use neorv32.neorv32_application_image.all; -- this file is generated by the image generator
use std.textio.all;
entity neorv32_tb_simple is
generic (
CPU_EXTENSION_RISCV_A : boolean := true;
CPU_EXTENSION_RISCV_B : boolean := true;
CPU_EXTENSION_RISCV_C : boolean := true;
CPU_EXTENSION_RISCV_E : boolean := false;
CPU_EXTENSION_RISCV_M : boolean := true;
CPU_EXTENSION_RISCV_U : boolean := true;
CPU_EXTENSION_RISCV_Zicsr : boolean := true;
CPU_EXTENSION_RISCV_Zifencei : boolean := true;
EXT_IMEM_C : boolean := false; -- false: use and boot from proc-internal IMEM, true: use and boot from external (initialized) simulated IMEM (ext. mem A)
MEM_INT_IMEM_SIZE : natural := 16*1024 -- size in bytes of processor-internal IMEM / external mem A
);
end neorv32_tb_simple;
architecture neorv32_tb_simple_rtl of neorv32_tb_simple is
-- User Configuration ---------------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
-- general --
constant ext_dmem_c : boolean := false; -- false: use proc-internal DMEM, true: use external simulated DMEM (ext. mem B)
constant dmem_size_c : natural := 8*1024; -- size in bytes of processor-internal DMEM / external mem B
constant f_clock_c : natural := 100000000; -- main clock in Hz
constant baud0_rate_c : natural := 19200; -- simulation UART0 (primary UART) baud rate
constant baud1_rate_c : natural := 19200; -- simulation UART1 (secondary UART) baud rate
-- simulated external Wishbone memory A (can be used as external IMEM) --
constant ext_mem_a_base_addr_c : std_ulogic_vector(31 downto 0) := x"00000000"; -- wishbone memory base address (external IMEM base)
constant ext_mem_a_size_c : natural := MEM_INT_IMEM_SIZE; -- wishbone memory size in bytes
constant ext_mem_a_latency_c : natural := 8; -- latency in clock cycles (min 1, max 255), plus 1 cycle initial delay
-- simulated external Wishbone memory B (can be used as external DMEM) --
constant ext_mem_b_base_addr_c : std_ulogic_vector(31 downto 0) := x"80000000"; -- wishbone memory base address (external DMEM base)
constant ext_mem_b_size_c : natural := dmem_size_c; -- wishbone memory size in bytes
constant ext_mem_b_latency_c : natural := 8; -- latency in clock cycles (min 1, max 255), plus 1 cycle initial delay
-- simulated external Wishbone memory C (can be used to simulate external IO access) --
constant ext_mem_c_base_addr_c : std_ulogic_vector(31 downto 0) := x"F0000000"; -- wishbone memory base address (default begin of EXTERNAL IO area)
constant ext_mem_c_size_c : natural := 64; -- wishbone memory size in bytes
constant ext_mem_c_latency_c : natural := 3; -- latency in clock cycles (min 1, max 255), plus 1 cycle initial delay
-- simulation interrupt trigger --
constant irq_trigger_base_addr_c : std_ulogic_vector(31 downto 0) := x"FF000000";
-- -------------------------------------------------------------------------------------------
-- internals - hands off! --
constant int_imem_c : boolean := not EXT_IMEM_C;
constant int_dmem_c : boolean := not ext_dmem_c;
constant uart0_baud_val_c : real := real(f_clock_c) / real(baud0_rate_c);
constant uart1_baud_val_c : real := real(f_clock_c) / real(baud1_rate_c);
constant t_clock_c : time := (1 sec) / f_clock_c;
-- generators --
signal clk_gen, rst_gen : std_ulogic := '0';
-- text.io --
file file_uart0_tx_out : text open write_mode is "neorv32.testbench_uart0.out";
-- uart --
signal uart0_txd : std_ulogic; -- local loop-back
signal uart0_cts : std_ulogic; -- local loop-back
signal uart1_txd : std_ulogic; -- local loop-back
signal uart1_cts : std_ulogic; -- local loop-back
-- gpio --
signal gpio : std_ulogic_vector(63 downto 0);
-- twi --
signal twi_scl, twi_sda : std_logic;
-- spi --
signal spi_data : std_ulogic;
-- irq --
signal msi_ring, mei_ring : std_ulogic;
-- Wishbone bus --
type wishbone_t is record
addr : std_ulogic_vector(31 downto 0); -- address
wdata : std_ulogic_vector(31 downto 0); -- master write data
rdata : std_ulogic_vector(31 downto 0); -- master read data
we : std_ulogic; -- write enable
sel : std_ulogic_vector(03 downto 0); -- byte enable
stb : std_ulogic; -- strobe
cyc : std_ulogic; -- valid cycle
ack : std_ulogic; -- transfer acknowledge
err : std_ulogic; -- transfer error
tag : std_ulogic_vector(02 downto 0); -- request tag
lock : std_ulogic; -- exclusive access request
end record;
signal wb_cpu, wb_mem_a, wb_mem_b, wb_mem_c, wb_irq : wishbone_t;
-- Wishbone access latency type --
type ext_mem_read_latency_t is array (0 to 255) of std_ulogic_vector(31 downto 0);
-- exclusive access / reservation --
signal ext_mem_c_atomic_reservation : std_ulogic := '0';
-- simulated external memory c (IO) --
signal ext_ram_c : mem32_t(0 to ext_mem_c_size_c/4-1); -- uninitialized, used to simulate external IO
-- simulated external memory bus feedback type --
type ext_mem_t is record
rdata : ext_mem_read_latency_t;
acc_en : std_ulogic;
ack : std_ulogic_vector(ext_mem_a_latency_c-1 downto 0);
end record;
signal ext_mem_a, ext_mem_b, ext_mem_c : ext_mem_t;
-- stream link interface - local echo --
signal slink_dat : sdata_8x32_t;
signal slink_val : std_ulogic_vector(7 downto 0);
signal slink_rdy : std_ulogic_vector(7 downto 0);
begin
-- Clock/Reset Generator ------------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
clk_gen <= not clk_gen after (t_clock_c/2);
rst_gen <= '0', '1' after 60*(t_clock_c/2);
-- The Core of the Problem ----------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
neorv32_top_inst: neorv32_top
generic map (
-- General --
CLOCK_FREQUENCY => f_clock_c, -- clock frequency of clk_i in Hz
HW_THREAD_ID => 0, -- hardware thread id (hartid) (32-bit)
INT_BOOTLOADER_EN => false, -- boot configuration: true = boot explicit bootloader; false = boot from int/ext (I)MEM
-- On-Chip Debugger (OCD) --
ON_CHIP_DEBUGGER_EN => true, -- implement on-chip debugger
-- RISC-V CPU Extensions --
CPU_EXTENSION_RISCV_A => CPU_EXTENSION_RISCV_A, -- implement atomic extension?
CPU_EXTENSION_RISCV_B => CPU_EXTENSION_RISCV_B, -- implement bit-manipulation extension?
CPU_EXTENSION_RISCV_C => CPU_EXTENSION_RISCV_C, -- implement compressed extension?
CPU_EXTENSION_RISCV_E => CPU_EXTENSION_RISCV_E, -- implement embedded RF extension?
CPU_EXTENSION_RISCV_M => CPU_EXTENSION_RISCV_M, -- implement muld/div extension?
CPU_EXTENSION_RISCV_U => CPU_EXTENSION_RISCV_U, -- implement user mode extension?
CPU_EXTENSION_RISCV_Zfinx => true, -- implement 32-bit floating-point extension (using INT reg!)
CPU_EXTENSION_RISCV_Zicsr => CPU_EXTENSION_RISCV_Zicsr, -- implement CSR system?
CPU_EXTENSION_RISCV_Zicntr => true, -- implement base counters?
CPU_EXTENSION_RISCV_Zihpm => true, -- implement hardware performance monitors?
CPU_EXTENSION_RISCV_Zifencei => CPU_EXTENSION_RISCV_Zifencei, -- implement instruction stream sync.?
CPU_EXTENSION_RISCV_Zmmul => false, -- implement multiply-only M sub-extension?
-- Extension Options --
FAST_MUL_EN => false, -- use DSPs for M extension's multiplier
FAST_SHIFT_EN => false, -- use barrel shifter for shift operations
CPU_CNT_WIDTH => 64, -- total width of CPU cycle and instret counters (0..64)
-- Physical Memory Protection (PMP) --
PMP_NUM_REGIONS => 8, -- number of regions (0..64)
PMP_MIN_GRANULARITY => 64*1024, -- minimal region granularity in bytes, has to be a power of 2, min 8 bytes
-- Hardware Performance Monitors (HPM) --
HPM_NUM_CNTS => 12, -- number of implemented HPM counters (0..29)
HPM_CNT_WIDTH => 40, -- total size of HPM counters (0..64)
-- Internal Instruction memory --
MEM_INT_IMEM_EN => int_imem_c , -- implement processor-internal instruction memory
MEM_INT_IMEM_SIZE => MEM_INT_IMEM_SIZE, -- size of processor-internal instruction memory in bytes
-- Internal Data memory --
MEM_INT_DMEM_EN => int_dmem_c, -- implement processor-internal data memory
MEM_INT_DMEM_SIZE => dmem_size_c, -- size of processor-internal data memory in bytes
-- Internal Cache memory --
ICACHE_EN => true, -- implement instruction cache
ICACHE_NUM_BLOCKS => 8, -- i-cache: number of blocks (min 2), has to be a power of 2
ICACHE_BLOCK_SIZE => 64, -- i-cache: block size in bytes (min 4), has to be a power of 2
ICACHE_ASSOCIATIVITY => 2, -- i-cache: associativity / number of sets (1=direct_mapped), has to be a power of 2
-- External memory interface --
MEM_EXT_EN => true, -- implement external memory bus interface?
MEM_EXT_TIMEOUT => 256, -- cycles after a pending bus access auto-terminates (0 = disabled)
-- Stream link interface --
SLINK_NUM_TX => 8, -- number of TX links (0..8)
SLINK_NUM_RX => 8, -- number of TX links (0..8)
SLINK_TX_FIFO => 4, -- TX fifo depth, has to be a power of two
SLINK_RX_FIFO => 1, -- RX fifo depth, has to be a power of two
-- External Interrupts Controller (XIRQ) --
XIRQ_NUM_CH => 32, -- number of external IRQ channels (0..32)
XIRQ_TRIGGER_TYPE => (others => '1'), -- trigger type: 0=level, 1=edge
XIRQ_TRIGGER_POLARITY => (others => '1'), -- trigger polarity: 0=low-level/falling-edge, 1=high-level/rising-edge
-- Processor peripherals --
IO_GPIO_EN => true, -- implement general purpose input/output port unit (GPIO)?
IO_MTIME_EN => true, -- implement machine system timer (MTIME)?
IO_UART0_EN => true, -- implement primary universal asynchronous receiver/transmitter (UART0)?
IO_UART0_RX_FIFO => 32, -- RX fifo depth, has to be a power of two, min 1
IO_UART0_TX_FIFO => 32, -- TX fifo depth, has to be a power of two, min 1
IO_UART1_EN => true, -- implement secondary universal asynchronous receiver/transmitter (UART1)?
IO_UART1_RX_FIFO => 1, -- RX fifo depth, has to be a power of two, min 1
IO_UART1_TX_FIFO => 1, -- TX fifo depth, has to be a power of two, min 1
IO_SPI_EN => true, -- implement serial peripheral interface (SPI)?
IO_TWI_EN => true, -- implement two-wire interface (TWI)?
IO_PWM_NUM_CH => 30, -- number of PWM channels to implement (0..60); 0 = disabled
IO_WDT_EN => true, -- implement watch dog timer (WDT)?
IO_TRNG_EN => false, -- trng cannot be simulated
IO_CFS_EN => true, -- implement custom functions subsystem (CFS)?
IO_CFS_CONFIG => (others => '0'), -- custom CFS configuration generic
IO_CFS_IN_SIZE => 32, -- size of CFS input conduit in bits
IO_CFS_OUT_SIZE => 32, -- size of CFS output conduit in bits
IO_NEOLED_EN => true, -- implement NeoPixel-compatible smart LED interface (NEOLED)?
IO_NEOLED_TX_FIFO => 8, -- NEOLED TX FIFO depth, 1..32k, has to be a power of two
IO_GPTMR_EN => true -- implement general purpose timer (GPTMR)?
)
port map (
-- Global control --
clk_i => clk_gen, -- global clock, rising edge
rstn_i => rst_gen, -- global reset, low-active, async
-- JTAG on-chip debugger interface (available if ON_CHIP_DEBUGGER_EN = true) --
jtag_trst_i => '1', -- low-active TAP reset (optional)
jtag_tck_i => '0', -- serial clock
jtag_tdi_i => '0', -- serial data input
jtag_tdo_o => open, -- serial data output
jtag_tms_i => '0', -- mode select
-- Wishbone bus interface (available if MEM_EXT_EN = true) --
wb_tag_o => wb_cpu.tag, -- request tag
wb_adr_o => wb_cpu.addr, -- address
wb_dat_i => wb_cpu.rdata, -- read data
wb_dat_o => wb_cpu.wdata, -- write data
wb_we_o => wb_cpu.we, -- read/write
wb_sel_o => wb_cpu.sel, -- byte enable
wb_stb_o => wb_cpu.stb, -- strobe
wb_cyc_o => wb_cpu.cyc, -- valid cycle
wb_lock_o => wb_cpu.lock, -- exclusive access request
wb_ack_i => wb_cpu.ack, -- transfer acknowledge
wb_err_i => wb_cpu.err, -- transfer error
-- Advanced memory control signals (available if MEM_EXT_EN = true) --
fence_o => open, -- indicates an executed FENCE operation
fencei_o => open, -- indicates an executed FENCEI operation
-- TX stream interfaces (available if SLINK_NUM_TX > 0) --
slink_tx_dat_o => slink_dat, -- output data
slink_tx_val_o => slink_val, -- valid output
slink_tx_rdy_i => slink_rdy, -- ready to send
-- RX stream interfaces (available if SLINK_NUM_RX > 0) --
slink_rx_dat_i => slink_dat, -- input data
slink_rx_val_i => slink_val, -- valid input
slink_rx_rdy_o => slink_rdy, -- ready to receive
-- GPIO (available if IO_GPIO_EN = true) --
gpio_o => gpio, -- parallel output
gpio_i => gpio, -- parallel input
-- primary UART0 (available if IO_UART0_EN = true) --
uart0_txd_o => uart0_txd, -- UART0 send data
uart0_rxd_i => uart0_txd, -- UART0 receive data
uart0_rts_o => uart0_cts, -- hw flow control: UART0.RX ready to receive ("RTR"), low-active, optional
uart0_cts_i => uart0_cts, -- hw flow control: UART0.TX allowed to transmit, low-active, optional
-- secondary UART1 (available if IO_UART1_EN = true) --
uart1_txd_o => uart1_txd, -- UART1 send data
uart1_rxd_i => uart1_txd, -- UART1 receive data
uart1_rts_o => uart1_cts, -- hw flow control: UART1.RX ready to receive ("RTR"), low-active, optional
uart1_cts_i => uart1_cts, -- hw flow control: UART1.TX allowed to transmit, low-active, optional
-- SPI (available if IO_SPI_EN = true) --
spi_sck_o => open, -- SPI serial clock
spi_sdo_o => spi_data, -- controller data out, peripheral data in
spi_sdi_i => spi_data, -- controller data in, peripheral data out
spi_csn_o => open, -- SPI CS
-- TWI (available if IO_TWI_EN = true) --
twi_sda_io => twi_sda, -- twi serial data line
twi_scl_io => twi_scl, -- twi serial clock line
-- PWM (available if IO_PWM_NUM_CH > 0) --
pwm_o => open, -- pwm channels
-- Custom Functions Subsystem IO --
cfs_in_i => (others => '0'), -- custom CFS inputs
cfs_out_o => open, -- custom CFS outputs
-- NeoPixel-compatible smart LED interface (available if IO_NEOLED_EN = true) --
neoled_o => open, -- async serial data line
-- System time --
mtime_i => (others => '0'), -- current system time from ext. MTIME (if IO_MTIME_EN = false)
mtime_o => open, -- current system time from int. MTIME (if IO_MTIME_EN = true)
-- External platform interrupts (available if XIRQ_NUM_CH > 0) --
xirq_i => gpio(31 downto 0), -- IRQ channels
-- CPU Interrupts --
mtime_irq_i => '0', -- machine software interrupt, available if IO_MTIME_EN = false
msw_irq_i => msi_ring, -- machine software interrupt
mext_irq_i => mei_ring -- machine external interrupt
);
-- TWI termination (pull-ups) --
twi_scl <= 'H';
twi_sda <= 'H';
-- UART Simulation Receiver ---------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
uart0_checker: entity work.uart_rx_simple
generic map (
name => "uart0",
uart_baud_val_c => uart0_baud_val_c
)
port map (
clk => clk_gen,
uart_txd => uart0_txd
);
uart1_checker: entity work.uart_rx_simple
generic map (
name => "uart1",
uart_baud_val_c => uart1_baud_val_c
)
port map (
clk => clk_gen,
uart_txd => uart1_txd
);
-- Wishbone Fabric ------------------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
-- CPU broadcast signals --
wb_mem_a.addr <= wb_cpu.addr;
wb_mem_a.wdata <= wb_cpu.wdata;
wb_mem_a.we <= wb_cpu.we;
wb_mem_a.sel <= wb_cpu.sel;
wb_mem_a.tag <= wb_cpu.tag;
wb_mem_a.cyc <= wb_cpu.cyc;
wb_mem_a.lock <= wb_cpu.lock;
wb_mem_b.addr <= wb_cpu.addr;
wb_mem_b.wdata <= wb_cpu.wdata;
wb_mem_b.we <= wb_cpu.we;
wb_mem_b.sel <= wb_cpu.sel;
wb_mem_b.tag <= wb_cpu.tag;
wb_mem_b.cyc <= wb_cpu.cyc;
wb_mem_b.lock <= wb_cpu.lock;
wb_mem_c.addr <= wb_cpu.addr;
wb_mem_c.wdata <= wb_cpu.wdata;
wb_mem_c.we <= wb_cpu.we;
wb_mem_c.sel <= wb_cpu.sel;
wb_mem_c.tag <= wb_cpu.tag;
wb_mem_c.cyc <= wb_cpu.cyc;
wb_mem_c.lock <= wb_cpu.lock;
wb_irq.addr <= wb_cpu.addr;
wb_irq.wdata <= wb_cpu.wdata;
wb_irq.we <= wb_cpu.we;
wb_irq.sel <= wb_cpu.sel;
wb_irq.tag <= wb_cpu.tag;
wb_irq.cyc <= wb_cpu.cyc;
-- CPU read-back signals (no mux here since peripherals have "output gates") --
wb_cpu.rdata <= wb_mem_a.rdata or wb_mem_b.rdata or wb_mem_c.rdata or wb_irq.rdata;
wb_cpu.ack <= wb_mem_a.ack or wb_mem_b.ack or wb_mem_c.ack or wb_irq.ack;
wb_cpu.err <= wb_mem_a.err or wb_mem_b.err or wb_mem_c.err or wb_irq.err;
-- peripheral select via STROBE signal --
wb_mem_a.stb <= wb_cpu.stb when (wb_cpu.addr >= ext_mem_a_base_addr_c) and (wb_cpu.addr < std_ulogic_vector(unsigned(ext_mem_a_base_addr_c) + ext_mem_a_size_c)) else '0';
wb_mem_b.stb <= wb_cpu.stb when (wb_cpu.addr >= ext_mem_b_base_addr_c) and (wb_cpu.addr < std_ulogic_vector(unsigned(ext_mem_b_base_addr_c) + ext_mem_b_size_c)) else '0';
wb_mem_c.stb <= wb_cpu.stb when (wb_cpu.addr >= ext_mem_c_base_addr_c) and (wb_cpu.addr < std_ulogic_vector(unsigned(ext_mem_c_base_addr_c) + ext_mem_c_size_c)) else '0';
wb_irq.stb <= wb_cpu.stb when (wb_cpu.addr = irq_trigger_base_addr_c) else '0';
-- Wishbone Memory A (simulated external IMEM) --------------------------------------------
-- -------------------------------------------------------------------------------------------
generate_ext_imem:
if (EXT_IMEM_C = true) generate
ext_mem_a_access: process(clk_gen)
variable ext_ram_a : mem32_t(0 to ext_mem_a_size_c/4-1) := mem32_init_f(application_init_image, ext_mem_a_size_c/4); -- initialized, used to simulate external IMEM
begin
if rising_edge(clk_gen) then
-- control --
ext_mem_a.ack(0) <= wb_mem_a.cyc and wb_mem_a.stb; -- wishbone acknowledge
-- write access --
if ((wb_mem_a.cyc and wb_mem_a.stb and wb_mem_a.we) = '1') then -- valid write access
for i in 0 to 3 loop
if (wb_mem_a.sel(i) = '1') then
ext_ram_a(to_integer(unsigned(wb_mem_a.addr(index_size_f(ext_mem_a_size_c/4)+1 downto 2))))(7+i*8 downto 0+i*8) := wb_mem_a.wdata(7+i*8 downto 0+i*8);
end if;
end loop; -- i
end if;
-- read access --
ext_mem_a.rdata(0) <= ext_ram_a(to_integer(unsigned(wb_mem_a.addr(index_size_f(ext_mem_a_size_c/4)+1 downto 2)))); -- word aligned
-- virtual read and ack latency --
if (ext_mem_a_latency_c > 1) then
for i in 1 to ext_mem_a_latency_c-1 loop
ext_mem_a.rdata(i) <= ext_mem_a.rdata(i-1);
ext_mem_a.ack(i) <= ext_mem_a.ack(i-1) and wb_mem_a.cyc;
end loop;
end if;
-- bus output register --
wb_mem_a.err <= '0';
if (ext_mem_a.ack(ext_mem_a_latency_c-1) = '1') and (wb_mem_a.cyc = '1') and (wb_mem_a.ack = '0') then
wb_mem_a.rdata <= ext_mem_a.rdata(ext_mem_a_latency_c-1);
wb_mem_a.ack <= '1';
else
wb_mem_a.rdata <= (others => '0');
wb_mem_a.ack <= '0';
end if;
end if;
end process ext_mem_a_access;
end generate;
generate_ext_imem_false:
if (EXT_IMEM_C = false) generate
wb_mem_a.rdata <= (others => '0');
wb_mem_a.ack <= '0';
wb_mem_a.err <= '0';
end generate;
-- Wishbone Memory B (simulated external DMEM) --------------------------------------------
-- -------------------------------------------------------------------------------------------
ext_mem_b_access: process(clk_gen)
variable ext_ram_b : mem32_t(0 to ext_mem_b_size_c/4-1) := (others => (others => '0')); -- zero, used to simulate external DMEM
begin
if rising_edge(clk_gen) then
-- control --
ext_mem_b.ack(0) <= wb_mem_b.cyc and wb_mem_b.stb; -- wishbone acknowledge
-- write access --
if ((wb_mem_b.cyc and wb_mem_b.stb and wb_mem_b.we) = '1') then -- valid write access
for i in 0 to 3 loop
if (wb_mem_b.sel(i) = '1') then
ext_ram_b(to_integer(unsigned(wb_mem_b.addr(index_size_f(ext_mem_b_size_c/4)+1 downto 2))))(7+i*8 downto 0+i*8) := wb_mem_b.wdata(7+i*8 downto 0+i*8);
end if;
end loop; -- i
end if;
-- read access --
ext_mem_b.rdata(0) <= ext_ram_b(to_integer(unsigned(wb_mem_b.addr(index_size_f(ext_mem_b_size_c/4)+1 downto 2)))); -- word aligned
-- virtual read and ack latency --
if (ext_mem_b_latency_c > 1) then
for i in 1 to ext_mem_b_latency_c-1 loop
ext_mem_b.rdata(i) <= ext_mem_b.rdata(i-1);
ext_mem_b.ack(i) <= ext_mem_b.ack(i-1) and wb_mem_b.cyc;
end loop;
end if;
-- bus output register --
wb_mem_b.err <= '0';
if (ext_mem_b.ack(ext_mem_b_latency_c-1) = '1') and (wb_mem_b.cyc = '1') and (wb_mem_b.ack = '0') then
wb_mem_b.rdata <= ext_mem_b.rdata(ext_mem_b_latency_c-1);
wb_mem_b.ack <= '1';
else
wb_mem_b.rdata <= (others => '0');
wb_mem_b.ack <= '0';
end if;
end if;
end process ext_mem_b_access;
-- Wishbone Memory C (simulated external IO) ----------------------------------------------
-- -------------------------------------------------------------------------------------------
ext_mem_c_access: process(clk_gen)
begin
if rising_edge(clk_gen) then
-- control --
ext_mem_c.ack(0) <= wb_mem_c.cyc and wb_mem_c.stb; -- wishbone acknowledge
-- write access --
if ((wb_mem_c.cyc and wb_mem_c.stb and wb_mem_c.we) = '1') then -- valid write access
for i in 0 to 3 loop
if (wb_mem_c.sel(i) = '1') then
ext_ram_c(to_integer(unsigned(wb_mem_c.addr(index_size_f(ext_mem_c_size_c/4)+1 downto 2))))(7+i*8 downto 0+i*8) <= wb_mem_c.wdata(7+i*8 downto 0+i*8);
end if;
end loop; -- i
end if;
-- read access --
ext_mem_c.rdata(0) <= ext_ram_c(to_integer(unsigned(wb_mem_c.addr(index_size_f(ext_mem_c_size_c/4)+1 downto 2)))); -- word aligned
-- virtual read and ack latency --
if (ext_mem_c_latency_c > 1) then
for i in 1 to ext_mem_c_latency_c-1 loop
ext_mem_c.rdata(i) <= ext_mem_c.rdata(i-1);
ext_mem_c.ack(i) <= ext_mem_c.ack(i-1) and wb_mem_c.cyc;
end loop;
end if;
-- EXCLUSIVE bus access -----------------------------------------------------
-- -----------------------------------------------------------------------------
-- Since there is only one CPU in this design, the exclusive access reservation in THIS memory CANNOT fail.
-- However, this memory module is used to simulated failing LR/SC accesses.
if ((wb_mem_c.cyc and wb_mem_c.stb) = '1') then -- valid access
ext_mem_c_atomic_reservation <= wb_mem_c.lock; -- make reservation
end if;
-- -----------------------------------------------------------------------------
-- bus output register --
if (ext_mem_c.ack(ext_mem_c_latency_c-1) = '1') and (wb_mem_c.cyc = '1') and (wb_mem_c.ack = '0') then
wb_mem_c.rdata <= ext_mem_c.rdata(ext_mem_c_latency_c-1);
wb_mem_c.ack <= '1';
wb_mem_c.err <= ext_mem_c_atomic_reservation; -- issue a bus error if there is an exclusive access request
else
wb_mem_c.rdata <= (others => '0');
wb_mem_c.ack <= '0';
wb_mem_c.err <= '0';
end if;
end if;
end process ext_mem_c_access;
-- Wishbone IRQ Triggers ------------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
irq_trigger: process(rst_gen, clk_gen)
begin
if (rst_gen = '0') then
msi_ring <= '0';
mei_ring <= '0';
elsif rising_edge(clk_gen) then
-- bus interface --
wb_irq.rdata <= (others => '0');
wb_irq.ack <= wb_irq.cyc and wb_irq.stb and wb_irq.we and and_reduce_f(wb_irq.sel);
wb_irq.err <= '0';
-- trigger RISC-V platform IRQs --
if ((wb_irq.cyc and wb_irq.stb and wb_irq.we and and_reduce_f(wb_irq.sel)) = '1') then
msi_ring <= wb_irq.wdata(03); -- machine software interrupt
mei_ring <= wb_irq.wdata(11); -- machine software interrupt
end if;
end if;
end process irq_trigger;
end neorv32_tb_simple_rtl;
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