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neorv32/sim/neorv32_tb.vhd

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-- #################################################################################################
-- # << NEORV32 - VUnit 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) 2024, 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 vunit_lib;
context vunit_lib.vunit_context;
context vunit_lib.com_context;
context vunit_lib.vc_context;
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;
library osvvm;
use osvvm.RandomPkg.all;
use work.uart_rx_pkg.all;
entity neorv32_tb is
generic (runner_cfg : string := runner_cfg_default;
ci_mode : boolean := false);
end neorv32_tb;
architecture neorv32_tb_rtl of neorv32_tb is
-- User Configuration ---------------------------------------------------------------------
-- -------------------------------------------------------------------------------------------
-- general --
constant int_imem_c : boolean := false; -- true: use proc-internal IMEM, false: use external simulated IMEM (ext. mem A)
constant int_dmem_c : boolean := false; -- true: use proc-internal DMEM, false: use external simulated DMEM (ext. mem B)
constant imem_size_c : natural := 32*1024; -- size in bytes of processor-internal IMEM / external mem A
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
constant icache_en_c : boolean := false; -- implement i-cache
constant icache_block_size_c : natural := 64; -- i-cache block size in bytes
-- 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 := imem_size_c; -- 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 := icache_block_size_c/2; -- wishbone memory size in bytes, should be smaller than an iCACHE block
constant ext_mem_c_latency_c : natural := 128; -- 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 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';
-- uart --
signal uart0_txd, uart1_txd : std_ulogic;
signal uart0_cts, uart1_cts : std_ulogic;
-- gpio --
signal gpio : std_ulogic_vector(63 downto 0);
-- twi --
signal twi_scl, twi_sda : std_logic;
signal twi_scl_i, twi_scl_o, twi_sda_i, twi_sda_o : std_ulogic;
-- 1-wire --
signal onewire : std_logic;
signal onewire_i, onewire_o : std_ulogic;
-- spi & sdi --
signal spi_csn: std_ulogic_vector(7 downto 0);
signal spi_di, spi_do, spi_clk : std_ulogic;
signal sdi_di, sdi_do, sdi_clk, sdi_csn : std_ulogic;
-- irq --
signal msi_ring, mei_ring : std_ulogic;
-- SLINK echo --
signal slink_dat : std_ulogic_vector(31 downto 0);
signal slink_val : std_ulogic;
signal slink_lst : std_ulogic;
signal slink_rdy : 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
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);
-- 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(255 downto 0);
end record;
signal ext_mem_a, ext_mem_b, ext_mem_c : ext_mem_t;
constant uart0_rx_logger : logger_t := get_logger("UART0.RX");
constant uart1_rx_logger : logger_t := get_logger("UART1.RX");
constant uart0_rx_handle : uart_rx_t := new_uart_rx(uart0_baud_val_c, uart0_rx_logger);
constant uart1_rx_handle : uart_rx_t := new_uart_rx(uart1_baud_val_c, uart1_rx_logger);
begin
test_runner : process
variable msg : msg_t;
variable rnd : RandomPType;
begin
test_runner_setup(runner, runner_cfg);
rnd.InitSeed(test_runner'path_name);
-- Show passing checks for UART0 on the display (stdout)
show(uart0_rx_logger, display_handler, pass);
show(uart1_rx_logger, display_handler, pass);
if ci_mode then
check_uart(net, uart0_rx_handle, nul & nul);
else
check_uart(net, uart0_rx_handle, "Blinking LED demo program" & cr & lf);
end if;
if ci_mode then
-- No need to send the full expectation in one big chunk
check_uart(net, uart1_rx_handle, nul & nul);
check_uart(net, uart1_rx_handle, "0/57" & cr & lf);
end if;
-- Wait until all expected data has been received
--
-- wait_until_idle can take the VC actor as argument but
-- the more abstract view is that wait_until_idle is part
-- of the sync VCI and to use it a VC must be cast
-- to a sync VC
wait_until_idle(net, as_sync(uart0_rx_handle));
wait_until_idle(net, as_sync(uart1_rx_handle));
-- Wait a bit more if some extra unexpected data is produced. If so,
-- uart_rx will fail
wait for (20 * (1e9 / baud0_rate_c)) * ns;
test_runner_cleanup(runner);
end process;
-- In case we get stuck waiting there is a watchdog timeout to terminate and fail the
-- testbench
test_runner_watchdog(runner, 50 ms);
-- 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
CLOCK_GATING_EN => true, -- enable clock gating when in sleep mode
HART_ID => x"00000000", -- hardware thread ID
VENDOR_ID => x"00000000", -- vendor's JEDEC ID
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 => true, -- implement atomic memory operations extension?
CPU_EXTENSION_RISCV_B => true, -- implement bit-manipulation extension?
CPU_EXTENSION_RISCV_C => true, -- implement compressed extension?
CPU_EXTENSION_RISCV_E => false, -- implement embedded RF extension?
CPU_EXTENSION_RISCV_M => true, -- implement mul/div extension?
CPU_EXTENSION_RISCV_U => true, -- implement user mode extension?
CPU_EXTENSION_RISCV_Zfinx => true, -- implement 32-bit floating-point extension (using INT reg!)
CPU_EXTENSION_RISCV_Zicntr => true, -- implement base counters?
CPU_EXTENSION_RISCV_Zicond => true, -- implement integer conditional operations?
CPU_EXTENSION_RISCV_Zihpm => true, -- implement hardware performance monitors?
CPU_EXTENSION_RISCV_Zmmul => false, -- implement multiply-only M sub-extension?
CPU_EXTENSION_RISCV_Zxcfu => true, -- implement custom (instr.) functions unit?
-- Extension Options --
FAST_MUL_EN => false, -- use DSPs for M extension's multiplier
FAST_SHIFT_EN => false, -- use barrel shifter for shift operations
REGFILE_HW_RST => true, -- full hardware reset
-- Physical Memory Protection (PMP) --
PMP_NUM_REGIONS => 5, -- number of regions (0..16)
PMP_MIN_GRANULARITY => 4, -- minimal region granularity in bytes, has to be a power of 2, min 4 bytes
PMP_TOR_MODE_EN => true, -- implement TOR mode
PMP_NAP_MODE_EN => true, -- implement NAPOT/NA4 mode
-- 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)
-- Atomic Memory Access - Reservation Set Granularity --
AMO_RVS_GRANULARITY => 4, -- size in bytes, has to be a power of 2, min 4
-- Internal Instruction memory --
MEM_INT_IMEM_EN => int_imem_c , -- implement processor-internal instruction memory
MEM_INT_IMEM_SIZE => imem_size_c, -- 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 => false, -- implement instruction cache
-- Internal Data Cache (dCACHE) --
DCACHE_EN => false, -- implement data cache
-- 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)
MEM_EXT_PIPE_MODE => false, -- protocol: false=classic/standard wishbone mode, true=pipelined wishbone mode
MEM_EXT_BIG_ENDIAN => false, -- byte order: true=big-endian, false=little-endian
MEM_EXT_ASYNC_RX => true, -- use register buffer for RX data when false
MEM_EXT_ASYNC_TX => true, -- use register buffer for TX data when false
-- Execute in-place module (XIP) --
XIP_EN => true, -- implement execute in place module (XIP)?
XIP_CACHE_EN => true, -- implement XIP cache?
XIP_CACHE_NUM_BLOCKS => 4, -- number of blocks (min 1), has to be a power of 2
XIP_CACHE_BLOCK_SIZE => 256, -- block size in bytes (min 4), has to be a power of 2
-- 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_NUM => 64, -- number of GPIO input/output pairs (0..64)
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_SPI_FIFO => 4, -- SPI RTX fifo depth, has to be zero or a power of two
IO_SDI_EN => true, -- implement serial data interface (SDI)?
IO_SDI_FIFO => 4, -- SDI RTX fifo depth, has to be zero or a power of two
IO_TWI_EN => true, -- implement two-wire interface (TWI)?
IO_PWM_NUM_CH => 12, -- number of PWM channels to implement (0..12); 0 = disabled
IO_WDT_EN => true, -- implement watch dog timer (WDT)?
IO_TRNG_EN => true, -- implement true random number generator (TRNG)?
IO_TRNG_FIFO => 4, -- TRNG fifo depth, has to be a power of two, min 1
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)?
IO_ONEWIRE_EN => true, -- implement 1-wire interface (ONEWIRE)?
IO_DMA_EN => true, -- implement direct memory access controller (DMA)?
IO_SLINK_EN => true, -- implement stream link interface (SLINK)?
IO_SLINK_RX_FIFO => 2, -- RX fifo depth, has to be a power of two, min 1
IO_SLINK_TX_FIFO => 2, -- TX fifo depth, has to be a power of two, min 1
IO_CRC_EN => true -- implement cyclic redundancy check unit (CRC)?
)
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_ack_i => wb_cpu.ack, -- transfer acknowledge
wb_err_i => wb_cpu.err, -- transfer error
-- Stream Link Interface (available if IO_SLINK_EN = true) --
slink_rx_dat_i => slink_dat, -- RX input data
slink_rx_val_i => slink_val, -- RX valid input
slink_rx_lst_i => slink_lst, -- last element of stream
slink_rx_rdy_o => slink_rdy, -- RX ready to receive
slink_tx_dat_o => slink_dat, -- TX output data
slink_tx_val_o => slink_val, -- TX valid output
slink_tx_lst_o => slink_lst, -- last element of stream
slink_tx_rdy_i => slink_rdy, -- TX ready to send
-- XIP (execute in place via SPI) signals (available if XIP_EN = true) --
xip_csn_o => open, -- chip-select, low-active
xip_clk_o => open, -- serial clock
xip_dat_i => '1', -- device data input
xip_dat_o => open, -- controller data output
-- GPIO (available if IO_GPIO_NUM > 0) --
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 => uart1_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 => uart0_cts, -- HW flow control: UART0.RX ready to receive ("RTR"), low-active, optional
uart1_cts_i => uart1_cts, -- HW flow control: UART0.TX allowed to transmit, low-active, optional
-- SPI (available if IO_SPI_EN = true) --
spi_clk_o => spi_clk, -- SPI serial clock
spi_dat_o => spi_do, -- controller data out, peripheral data in
spi_dat_i => spi_di, -- controller data in, peripheral data out
spi_csn_o => spi_csn, -- SPI CS
-- SDI (available if IO_SDI_EN = true) --
sdi_clk_i => sdi_clk, -- SDI serial clock
sdi_dat_o => sdi_do, -- controller data out, peripheral data in
sdi_dat_i => sdi_di, -- controller data in, peripheral data out
sdi_csn_i => sdi_csn, -- chip-select
-- TWI (available if IO_TWI_EN = true) --
twi_sda_i => twi_sda_i, -- serial data line sense input
twi_sda_o => twi_sda_o, -- serial data line output (pull low only)
twi_scl_i => twi_scl_i, -- serial clock line sense input
twi_scl_o => twi_scl_o, -- serial clock line output (pull low only)
-- 1-Wire Interface (available if IO_ONEWIRE_EN = true) --
onewire_i => onewire_i, -- 1-wire bus sense input
onewire_o => onewire_o, -- 1-wire bus output (pull low only)
-- 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
-- Machine timer system time (available if IO_MTIME_EN = true) --
mtime_time_o => open,
-- GPTMR timer capture (available if IO_GPTMR_EN = true) --
gptmr_trig_i => gpio(63), -- capture trigger
-- 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 tri-state driver --
twi_sda <= '0' when (twi_sda_o = '0') else 'Z'; -- module can only pull the line low actively
twi_scl <= '0' when (twi_scl_o = '0') else 'Z';
twi_sda_i <= std_ulogic(twi_sda);
twi_scl_i <= std_ulogic(twi_scl);
-- 1-Wire tri-state driver --
onewire <= '0' when (onewire_o = '0') else 'Z'; -- module can only pull the line low actively
onewire_i <= std_ulogic(onewire);
-- TWI termination (pull-ups) --
twi_scl <= 'H';
twi_sda <= 'H';
-- 1-Wire termination (pull-up) --
onewire <= 'H';
-- SPI/SDI echo --
sdi_clk <= spi_clk;
sdi_csn <= spi_csn(7);
sdi_di <= spi_do;
spi_di <= sdi_do when (spi_csn(7) = '0') else spi_do;
uart0_checker: entity work.uart_rx
generic map (uart0_rx_handle)
port map (
clk => clk_gen,
uart_txd => uart0_txd);
uart1_checker: entity work.uart_rx
generic map (uart1_rx_handle)
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_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_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_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 (int_imem_c = false) 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') 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 (int_imem_c = true) 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) --------------------------------------------
-- -------------------------------------------------------------------------------------------
generate_ext_dmem:
if (int_dmem_c = false) generate
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') 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;
end generate;
generate_ext_dmem_false:
if (int_dmem_c = true) generate
wb_mem_b.rdata <= (others => '0');
wb_mem_b.ack <= '0';
wb_mem_b.err <= '0';
end generate;
-- 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;
-- bus output register --
if (ext_mem_c.ack(ext_mem_c_latency_c-1) = '1') and (wb_mem_c.cyc = '1') then
wb_mem_c.rdata <= ext_mem_c.rdata(ext_mem_c_latency_c-1);
wb_mem_c.ack <= '1';
wb_mem_c.err <= '0';
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_rtl;
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