-- #################################################################################################
|
-- #################################################################################################
|
-- # << NEORV32 - Simple Testbench >> #
|
-- # << NEORV32 - Simple Testbench >> #
|
-- # ********************************************************************************************* #
|
-- # ********************************************************************************************* #
|
-- # This testbench provides a virtual UART receiver connected to the processor's uart_txd_o #
|
-- # This testbench provides a virtual UART receiver connected to the processor's uart_txd_o #
|
-- # signals. The received chars are shown in the simulator console and also written to a file #
|
-- # signals. The received chars are shown in the simulator console and also written to a file #
|
-- # ("neorv32.testbench_uart.out"). #
|
-- # ("neorv32.testbench_uart.out"). #
|
-- # Futhermore, this testbench provides a simple RAM connected to the external Wishbone bus. #
|
-- # Futhermore, this testbench provides a simple RAM connected to the external Wishbone bus. #
|
-- # The testbench configures the processor with all optional element enabled by default. #
|
-- # The testbench configures the processor with all optional element enabled by default. #
|
-- # ********************************************************************************************* #
|
-- # ********************************************************************************************* #
|
-- # BSD 3-Clause License #
|
-- # BSD 3-Clause License #
|
-- # #
|
-- # #
|
-- # Copyright (c) 2020, Stephan Nolting. All rights reserved. #
|
-- # Copyright (c) 2020, Stephan Nolting. All rights reserved. #
|
-- # #
|
-- # #
|
-- # Redistribution and use in source and binary forms, with or without modification, are #
|
-- # Redistribution and use in source and binary forms, with or without modification, are #
|
-- # permitted provided that the following conditions are met: #
|
-- # permitted provided that the following conditions are met: #
|
-- # #
|
-- # #
|
-- # 1. Redistributions of source code must retain the above copyright notice, this list of #
|
-- # 1. Redistributions of source code must retain the above copyright notice, this list of #
|
-- # conditions and the following disclaimer. #
|
-- # conditions and the following disclaimer. #
|
-- # #
|
-- # #
|
-- # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
|
-- # 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 #
|
-- # conditions and the following disclaimer in the documentation and/or other materials #
|
-- # provided with the distribution. #
|
-- # provided with the distribution. #
|
-- # #
|
-- # #
|
-- # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
|
-- # 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 #
|
-- # endorse or promote products derived from this software without specific prior written #
|
-- # permission. #
|
-- # permission. #
|
-- # #
|
-- # #
|
-- # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
|
-- # 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 #
|
-- # 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 #
|
-- # 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, #
|
-- # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
|
-- # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
|
-- # 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 #
|
-- # 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 #
|
-- # 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 #
|
-- # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
|
-- # OF THE POSSIBILITY OF SUCH DAMAGE. #
|
-- # OF THE POSSIBILITY OF SUCH DAMAGE. #
|
-- # ********************************************************************************************* #
|
-- # ********************************************************************************************* #
|
-- # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
|
-- # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
|
-- #################################################################################################
|
-- #################################################################################################
|
|
|
library ieee;
|
library ieee;
|
use ieee.std_logic_1164.all;
|
use ieee.std_logic_1164.all;
|
use ieee.numeric_std.all;
|
use ieee.numeric_std.all;
|
use ieee.math_real.all;
|
use ieee.math_real.all;
|
|
|
library neorv32;
|
library neorv32;
|
use neorv32.neorv32_package.all;
|
use neorv32.neorv32_package.all;
|
|
use neorv32.neorv32_application_image.all; -- this file is generated by the image generator
|
use std.textio.all;
|
use std.textio.all;
|
|
|
entity neorv32_tb is
|
entity neorv32_tb is
|
end neorv32_tb;
|
end neorv32_tb;
|
|
|
architecture neorv32_tb_rtl of neorv32_tb is
|
architecture neorv32_tb_rtl of neorv32_tb is
|
|
|
-- User Configuration ---------------------------------------------------------------------
|
-- User Configuration ---------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
constant t_clock_c : time := 10 ns; -- main clock period
|
constant t_clock_c : time := 10 ns; -- main clock period
|
constant f_clock_c : real := 100000000.0; -- main clock in Hz
|
constant f_clock_c : real := 100000000.0; -- main clock in Hz
|
constant f_clock_nat_c : natural := 100000000; -- main clock in Hz
|
constant f_clock_nat_c : natural := 100000000; -- main clock in Hz
|
constant baud_rate_c : real := 19200.0; -- standard UART baudrate
|
constant baud_rate_c : real := 19200.0; -- standard UART baudrate
|
|
--
|
constant wb_mem_base_addr_c : std_ulogic_vector(31 downto 0) := x"F0000000"; -- wishbone memory base address
|
constant wb_mem_base_addr_c : std_ulogic_vector(31 downto 0) := x"F0000000"; -- wishbone memory base address
|
constant wb_mem_size_c : natural := 256; -- wishbone memory size in bytes
|
constant wb_mem_size_c : natural := 256; -- wishbone memory size in bytes
|
constant wb_mem_latency_c : natural := 8; -- latency in clock cycles (min 1)
|
constant wb_mem_latency_c : natural := 8; -- latency in clock cycles (min 1)
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
|
|
-- text.io --
|
-- text.io --
|
file file_uart_tx_out : text open write_mode is "neorv32.testbench_uart.out";
|
file file_uart_tx_out : text open write_mode is "neorv32.testbench_uart.out";
|
|
|
-- internal configuration --
|
-- internal configuration --
|
constant baud_val_c : real := f_clock_c / baud_rate_c;
|
constant baud_val_c : real := f_clock_c / baud_rate_c;
|
constant f_clk_c : natural := natural(f_clock_c);
|
constant f_clk_c : natural := natural(f_clock_c);
|
|
|
-- generators --
|
-- generators --
|
signal clk_gen, rst_gen : std_ulogic := '0';
|
signal clk_gen, rst_gen : std_ulogic := '0';
|
|
|
-- simulation uart receiver --
|
-- simulation uart receiver --
|
signal uart_txd : std_ulogic;
|
signal uart_txd : std_ulogic;
|
signal uart_rx_sync : std_ulogic_vector(04 downto 0) := (others => '1');
|
signal uart_rx_sync : std_ulogic_vector(04 downto 0) := (others => '1');
|
signal uart_rx_busy : std_ulogic := '0';
|
signal uart_rx_busy : std_ulogic := '0';
|
signal uart_rx_sreg : std_ulogic_vector(08 downto 0) := (others => '0');
|
signal uart_rx_sreg : std_ulogic_vector(08 downto 0) := (others => '0');
|
signal uart_rx_baud_cnt : real;
|
signal uart_rx_baud_cnt : real;
|
signal uart_rx_bitcnt : natural;
|
signal uart_rx_bitcnt : natural;
|
|
|
-- gpio --
|
-- gpio --
|
signal gpio : std_ulogic_vector(31 downto 0);
|
signal gpio : std_ulogic_vector(31 downto 0);
|
|
|
-- twi --
|
-- twi --
|
signal twi_scl, twi_sda : std_logic;
|
signal twi_scl, twi_sda : std_logic;
|
|
|
-- spi --
|
-- spi --
|
signal spi_data : std_logic;
|
signal spi_data : std_logic;
|
|
|
-- Wishbone bus --
|
-- Wishbone bus --
|
type wishbone_t is record
|
type wishbone_t is record
|
addr : std_ulogic_vector(31 downto 0); -- address
|
addr : std_ulogic_vector(31 downto 0); -- address
|
wdata : std_ulogic_vector(31 downto 0); -- master write data
|
wdata : std_ulogic_vector(31 downto 0); -- master write data
|
rdata : std_ulogic_vector(31 downto 0); -- master read data
|
rdata : std_ulogic_vector(31 downto 0); -- master read data
|
we : std_ulogic; -- write enable
|
we : std_ulogic; -- write enable
|
sel : std_ulogic_vector(03 downto 0); -- byte enable
|
sel : std_ulogic_vector(03 downto 0); -- byte enable
|
stb : std_ulogic; -- strobe
|
stb : std_ulogic; -- strobe
|
cyc : std_ulogic; -- valid cycle
|
cyc : std_ulogic; -- valid cycle
|
ack : std_ulogic; -- transfer acknowledge
|
ack : std_ulogic; -- transfer acknowledge
|
err : std_ulogic; -- transfer error
|
err : std_ulogic; -- transfer error
|
end record;
|
end record;
|
signal wb_cpu : wishbone_t;
|
signal wb_cpu : wishbone_t;
|
|
|
-- Wishbone memory --
|
-- Wishbone memory --
|
type wb_mem_ram_t is array (0 to wb_mem_size_c/4-1) of std_ulogic_vector(31 downto 0);
|
type wb_mem_ram_t is array (0 to wb_mem_size_c/4-1) of std_ulogic_vector(31 downto 0);
|
type wb_mem_read_latency_t is array (0 to wb_mem_latency_c-1) of std_ulogic_vector(31 downto 0);
|
type wb_mem_read_latency_t is array (0 to wb_mem_latency_c-1) of std_ulogic_vector(31 downto 0);
|
|
|
|
-- init function --
|
|
-- impure function: returns NOT the same result every time it is evaluated with the same arguments since the source file might have changed
|
|
impure function init_wbmem(init : application_init_image_t) return wb_mem_ram_t is
|
|
variable mem_v : wb_mem_ram_t;
|
|
begin
|
|
mem_v := (others => (others => '0'));
|
|
for i in 0 to init'length-1 loop -- init only in range of source data array
|
|
mem_v(i) := init(i);
|
|
end loop; -- i
|
|
return mem_v;
|
|
end function init_wbmem;
|
|
|
|
-- ---------------------------------------------- --
|
|
-- How to simulate a boot from an external memory --
|
|
-- ---------------------------------------------- --
|
|
-- The simulated Wishbone memory can be initialized with the compiled application init.
|
|
-- 1. Uncomment the init_wbmen function below
|
|
-- 2. Increase the wb_mem_size_c constant above to (at least) the size of the application image (like 16kB)
|
|
-- 3. Disable the processor-internal IMEM in the processor instantiation below (MEM_INT_IMEM_USE => false)
|
|
-- 4. Set the Wishbone memory base address wb_mem_base_addr_c (above) to zero (constant wb_mem_base_addr_c : std_ulogic_vector(31 downto 0) := x"00000000";)
|
|
-- 5. Simulate!
|
|
|
|
signal wb_ram : wb_mem_ram_t;-- := init_wbmem(application_init_image); -- uncomment if you want to init the WB ram with app image
|
|
|
type wb_mem_t is record
|
type wb_mem_t is record
|
ram : wb_mem_ram_t;
|
|
rdata : wb_mem_read_latency_t;
|
rdata : wb_mem_read_latency_t;
|
acc_en : std_ulogic;
|
acc_en : std_ulogic;
|
ack : std_ulogic_vector(wb_mem_latency_c-1 downto 0);
|
ack : std_ulogic_vector(wb_mem_latency_c-1 downto 0);
|
rb_en : std_ulogic_vector(wb_mem_latency_c-1 downto 0);
|
rb_en : std_ulogic_vector(wb_mem_latency_c-1 downto 0);
|
end record;
|
end record;
|
signal wb_mem : wb_mem_t;
|
signal wb_mem : wb_mem_t;
|
|
|
begin
|
begin
|
|
|
-- Clock/Reset Generator ------------------------------------------------------------------
|
-- Clock/Reset Generator ------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
clk_gen <= not clk_gen after (t_clock_c/2);
|
clk_gen <= not clk_gen after (t_clock_c/2);
|
rst_gen <= '0', '1' after 60*(t_clock_c/2);
|
rst_gen <= '0', '1' after 60*(t_clock_c/2);
|
|
|
|
|
-- CPU Core -------------------------------------------------------------------------------
|
-- CPU Core -------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
neorv32_top_inst: neorv32_top
|
neorv32_top_inst: neorv32_top
|
generic map (
|
generic map (
|
-- General --
|
-- General --
|
CLOCK_FREQUENCY => f_clock_nat_c, -- clock frequency of clk_i in Hz
|
CLOCK_FREQUENCY => f_clock_nat_c, -- clock frequency of clk_i in Hz
|
BOOTLOADER_USE => false, -- implement processor-internal bootloader?
|
BOOTLOADER_USE => false, -- implement processor-internal bootloader?
|
USER_CODE => x"19880704", -- custom user code
|
USER_CODE => x"19880704", -- custom user code
|
-- RISC-V CPU Extensions --
|
-- RISC-V CPU Extensions --
|
CPU_EXTENSION_RISCV_C => true, -- implement compressed extension?
|
CPU_EXTENSION_RISCV_C => true, -- implement compressed extension?
|
CPU_EXTENSION_RISCV_E => false, -- implement embedded RF extension?
|
CPU_EXTENSION_RISCV_E => false, -- implement embedded RF extension?
|
CPU_EXTENSION_RISCV_M => true, -- implement muld/div extension?
|
CPU_EXTENSION_RISCV_M => true, -- implement muld/div extension?
|
CPU_EXTENSION_RISCV_U => true, -- implement user mode extension?
|
CPU_EXTENSION_RISCV_U => true, -- implement user mode extension?
|
CPU_EXTENSION_RISCV_Zicsr => true, -- implement CSR system?
|
CPU_EXTENSION_RISCV_Zicsr => true, -- implement CSR system?
|
CPU_EXTENSION_RISCV_Zifencei => true, -- implement instruction stream sync.?
|
CPU_EXTENSION_RISCV_Zifencei => true, -- implement instruction stream sync.?
|
-- Extension Options --
|
-- Extension Options --
|
FAST_MUL_EN => false, -- use DSPs for M extension's multiplier
|
FAST_MUL_EN => false, -- use DSPs for M extension's multiplier
|
-- Physical Memory Protection (PMP) --
|
-- Physical Memory Protection (PMP) --
|
PMP_USE => true, -- implement PMP?
|
PMP_USE => true, -- implement PMP?
|
PMP_NUM_REGIONS => 4, -- number of regions (max 16)
|
PMP_NUM_REGIONS => 4, -- number of regions (max 16)
|
PMP_GRANULARITY => 14, -- minimal region granularity (1=8B, 2=16B, 3=32B, ...) default is 64k
|
PMP_GRANULARITY => 14, -- minimal region granularity (1=8B, 2=16B, 3=32B, ...) default is 64k
|
-- Internal Instruction memory --
|
-- Internal Instruction memory --
|
MEM_INT_IMEM_USE => true, -- implement processor-internal instruction memory
|
MEM_INT_IMEM_USE => true, -- implement processor-internal instruction memory
|
MEM_INT_IMEM_SIZE => 16*1024, -- size of processor-internal instruction memory in bytes
|
MEM_INT_IMEM_SIZE => 16*1024, -- size of processor-internal instruction memory in bytes
|
MEM_INT_IMEM_ROM => false, -- implement processor-internal instruction memory as ROM
|
MEM_INT_IMEM_ROM => false, -- implement processor-internal instruction memory as ROM
|
-- Internal Data memory --
|
-- Internal Data memory --
|
MEM_INT_DMEM_USE => true, -- implement processor-internal data memory
|
MEM_INT_DMEM_USE => true, -- implement processor-internal data memory
|
MEM_INT_DMEM_SIZE => 8*1024, -- size of processor-internal data memory in bytes
|
MEM_INT_DMEM_SIZE => 8*1024, -- size of processor-internal data memory in bytes
|
-- External memory interface --
|
-- External memory interface --
|
MEM_EXT_USE => true, -- implement external memory bus interface?
|
MEM_EXT_USE => true, -- implement external memory bus interface?
|
MEM_EXT_REG_STAGES => 2, -- number of interface register stages (0,1,2)
|
MEM_EXT_REG_STAGES => 2, -- number of interface register stages (0,1,2)
|
MEM_EXT_TIMEOUT => 15, -- cycles after which a valid bus access will timeout
|
|
-- Processor peripherals --
|
-- Processor peripherals --
|
IO_GPIO_USE => true, -- implement general purpose input/output port unit (GPIO)?
|
IO_GPIO_USE => true, -- implement general purpose input/output port unit (GPIO)?
|
IO_MTIME_USE => true, -- implement machine system timer (MTIME)?
|
IO_MTIME_USE => true, -- implement machine system timer (MTIME)?
|
IO_UART_USE => true, -- implement universal asynchronous receiver/transmitter (UART)?
|
IO_UART_USE => true, -- implement universal asynchronous receiver/transmitter (UART)?
|
IO_SPI_USE => true, -- implement serial peripheral interface (SPI)?
|
IO_SPI_USE => true, -- implement serial peripheral interface (SPI)?
|
IO_TWI_USE => true, -- implement two-wire interface (TWI)?
|
IO_TWI_USE => true, -- implement two-wire interface (TWI)?
|
IO_PWM_USE => true, -- implement pulse-width modulation unit (PWM)?
|
IO_PWM_USE => true, -- implement pulse-width modulation unit (PWM)?
|
IO_WDT_USE => true, -- implement watch dog timer (WDT)?
|
IO_WDT_USE => true, -- implement watch dog timer (WDT)?
|
IO_TRNG_USE => false, -- DEFAULT TRNG CONFIG CANNOT BE SIMULATED!
|
IO_TRNG_USE => false, -- DEFAULT TRNG CONFIG CANNOT BE SIMULATED!
|
IO_DEVNULL_USE => true, -- implement dummy device (DEVNULL)?
|
|
IO_CFU_USE => true -- implement custom functions unit (CFU)?
|
IO_CFU_USE => true -- implement custom functions unit (CFU)?
|
)
|
)
|
port map (
|
port map (
|
-- Global control --
|
-- Global control --
|
clk_i => clk_gen, -- global clock, rising edge
|
clk_i => clk_gen, -- global clock, rising edge
|
rstn_i => rst_gen, -- global reset, low-active, async
|
rstn_i => rst_gen, -- global reset, low-active, async
|
-- Wishbone bus interface --
|
-- Wishbone bus interface --
|
wb_adr_o => wb_cpu.addr, -- address
|
wb_adr_o => wb_cpu.addr, -- address
|
wb_dat_i => wb_cpu.rdata, -- read data
|
wb_dat_i => wb_cpu.rdata, -- read data
|
wb_dat_o => wb_cpu.wdata, -- write data
|
wb_dat_o => wb_cpu.wdata, -- write data
|
wb_we_o => wb_cpu.we, -- read/write
|
wb_we_o => wb_cpu.we, -- read/write
|
wb_sel_o => wb_cpu.sel, -- byte enable
|
wb_sel_o => wb_cpu.sel, -- byte enable
|
wb_stb_o => wb_cpu.stb, -- strobe
|
wb_stb_o => wb_cpu.stb, -- strobe
|
wb_cyc_o => wb_cpu.cyc, -- valid cycle
|
wb_cyc_o => wb_cpu.cyc, -- valid cycle
|
wb_ack_i => wb_cpu.ack, -- transfer acknowledge
|
wb_ack_i => wb_cpu.ack, -- transfer acknowledge
|
wb_err_i => wb_cpu.err, -- transfer error
|
wb_err_i => wb_cpu.err, -- transfer error
|
-- Advanced memory control signals --
|
-- Advanced memory control signals --
|
fence_o => open, -- indicates an executed FENCE operation
|
fence_o => open, -- indicates an executed FENCE operation
|
fencei_o => open, -- indicates an executed FENCEI operation
|
fencei_o => open, -- indicates an executed FENCEI operation
|
-- GPIO --
|
-- GPIO --
|
gpio_o => gpio, -- parallel output
|
gpio_o => gpio, -- parallel output
|
gpio_i => gpio, -- parallel input
|
gpio_i => gpio, -- parallel input
|
-- UART --
|
-- UART --
|
uart_txd_o => uart_txd, -- UART send data
|
uart_txd_o => uart_txd, -- UART send data
|
uart_rxd_i => uart_txd, -- UART receive data
|
uart_rxd_i => uart_txd, -- UART receive data
|
-- SPI --
|
-- SPI --
|
spi_sck_o => open, -- SPI serial clock
|
spi_sck_o => open, -- SPI serial clock
|
spi_sdo_o => spi_data, -- controller data out, peripheral data in
|
spi_sdo_o => spi_data, -- controller data out, peripheral data in
|
spi_sdi_i => spi_data, -- controller data in, peripheral data out
|
spi_sdi_i => spi_data, -- controller data in, peripheral data out
|
spi_csn_o => open, -- SPI CS
|
spi_csn_o => open, -- SPI CS
|
-- TWI --
|
-- TWI --
|
twi_sda_io => twi_sda, -- twi serial data line
|
twi_sda_io => twi_sda, -- twi serial data line
|
twi_scl_io => twi_scl, -- twi serial clock line
|
twi_scl_io => twi_scl, -- twi serial clock line
|
-- PWM --
|
-- PWM --
|
pwm_o => open, -- pwm channels
|
pwm_o => open, -- pwm channels
|
-- Interrupts --
|
-- Interrupts --
|
mext_irq_i => '0' -- machine external interrupt
|
mext_irq_i => '0' -- machine external interrupt
|
);
|
);
|
|
|
-- TWI termination --
|
-- TWI termination --
|
twi_scl <= 'H';
|
twi_scl <= 'H';
|
twi_sda <= 'H';
|
twi_sda <= 'H';
|
|
|
|
|
-- Console UART Receiver ------------------------------------------------------------------
|
-- Console UART Receiver ------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
uart_rx_console: process(clk_gen)
|
uart_rx_console: process(clk_gen)
|
variable i : integer;
|
variable i : integer;
|
variable l : line;
|
variable l : line;
|
begin
|
begin
|
-- "UART" --
|
-- "UART" --
|
if rising_edge(clk_gen) then
|
if rising_edge(clk_gen) then
|
-- synchronizer --
|
-- synchronizer --
|
uart_rx_sync <= uart_rx_sync(3 downto 0) & uart_txd;
|
uart_rx_sync <= uart_rx_sync(3 downto 0) & uart_txd;
|
-- arbiter --
|
-- arbiter --
|
if (uart_rx_busy = '0') then -- idle
|
if (uart_rx_busy = '0') then -- idle
|
uart_rx_busy <= '0';
|
uart_rx_busy <= '0';
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uart_rx_baud_cnt <= round(0.5 * baud_val_c);
|
uart_rx_baud_cnt <= round(0.5 * baud_val_c);
|
uart_rx_bitcnt <= 9;
|
uart_rx_bitcnt <= 9;
|
if (uart_rx_sync(4 downto 1) = "1100") then -- start bit? (falling edge)
|
if (uart_rx_sync(4 downto 1) = "1100") then -- start bit? (falling edge)
|
uart_rx_busy <= '1';
|
uart_rx_busy <= '1';
|
end if;
|
end if;
|
else
|
else
|
if (uart_rx_baud_cnt = 0.0) then
|
if (uart_rx_baud_cnt = 0.0) then
|
if (uart_rx_bitcnt = 1) then
|
if (uart_rx_bitcnt = 1) then
|
uart_rx_baud_cnt <= round(0.5 * baud_val_c);
|
uart_rx_baud_cnt <= round(0.5 * baud_val_c);
|
else
|
else
|
uart_rx_baud_cnt <= round(baud_val_c);
|
uart_rx_baud_cnt <= round(baud_val_c);
|
end if;
|
end if;
|
if (uart_rx_bitcnt = 0) then
|
if (uart_rx_bitcnt = 0) then
|
uart_rx_busy <= '0'; -- done
|
uart_rx_busy <= '0'; -- done
|
i := to_integer(unsigned(uart_rx_sreg(8 downto 1)));
|
i := to_integer(unsigned(uart_rx_sreg(8 downto 1)));
|
|
|
if (i < 32) or (i > 32+95) then -- printable char?
|
if (i < 32) or (i > 32+95) then -- printable char?
|
report "SIM_UART TX: (" & integer'image(i) & ")"; -- print code
|
report "SIM_UART TX: (" & integer'image(i) & ")"; -- print code
|
else
|
else
|
report "SIM_UART TX: " & character'val(i); -- print ASCII
|
report "SIM_UART TX: " & character'val(i); -- print ASCII
|
end if;
|
end if;
|
|
|
if (i = 10) then -- Linux line break
|
if (i = 10) then -- Linux line break
|
writeline(file_uart_tx_out, l);
|
writeline(file_uart_tx_out, l);
|
elsif (i /= 13) then -- Remove additional carriage return
|
elsif (i /= 13) then -- Remove additional carriage return
|
write(l, character'val(i));
|
write(l, character'val(i));
|
end if;
|
end if;
|
else
|
else
|
uart_rx_sreg <= uart_rx_sync(4) & uart_rx_sreg(8 downto 1);
|
uart_rx_sreg <= uart_rx_sync(4) & uart_rx_sreg(8 downto 1);
|
uart_rx_bitcnt <= uart_rx_bitcnt - 1;
|
uart_rx_bitcnt <= uart_rx_bitcnt - 1;
|
end if;
|
end if;
|
else
|
else
|
uart_rx_baud_cnt <= uart_rx_baud_cnt - 1.0;
|
uart_rx_baud_cnt <= uart_rx_baud_cnt - 1.0;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end process uart_rx_console;
|
end process uart_rx_console;
|
|
|
|
|
-- Wishbone Memory ------------------------------------------------------------------------
|
-- Wishbone Memory (simulated external memory) --------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
-- -------------------------------------------------------------------------------------------
|
wb_mem_ram_access: process(clk_gen)
|
wb_mem_ram_access: process(clk_gen)
|
begin
|
begin
|
if rising_edge(clk_gen) then
|
if rising_edge(clk_gen) then
|
-- control --
|
-- control --
|
wb_mem.rb_en(0) <= wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en and (not wb_cpu.we); -- read-back control
|
wb_mem.rb_en(0) <= wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en and (not wb_cpu.we); -- read-back control
|
wb_mem.ack(0) <= wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en; -- wishbone acknowledge
|
wb_mem.ack(0) <= wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en; -- wishbone acknowledge
|
-- write access --
|
-- write access --
|
if ((wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en and wb_cpu.we) = '1') then -- valid write access
|
if ((wb_cpu.cyc and wb_cpu.stb and wb_mem.acc_en and wb_cpu.we) = '1') then -- valid write access
|
for i in 0 to 3 loop
|
for i in 0 to 3 loop
|
if (wb_cpu.sel(i) = '1') then
|
if (wb_cpu.sel(i) = '1') then
|
wb_mem.ram(to_integer(unsigned(wb_cpu.addr(index_size_f(wb_mem_size_c/4)+1 downto 2))))(7+i*8 downto 0+i*8) <= wb_cpu.wdata(7+i*8 downto 0+i*8);
|
wb_ram(to_integer(unsigned(wb_cpu.addr(index_size_f(wb_mem_size_c/4)+1 downto 2))))(7+i*8 downto 0+i*8) <= wb_cpu.wdata(7+i*8 downto 0+i*8);
|
end if;
|
end if;
|
end loop; -- i
|
end loop; -- i
|
end if;
|
end if;
|
-- read access --
|
-- read access --
|
wb_mem.rdata(0) <= wb_mem.ram(to_integer(unsigned(wb_cpu.addr(index_size_f(wb_mem_size_c/4)+1 downto 2)))); -- word aligned
|
wb_mem.rdata(0) <= wb_ram(to_integer(unsigned(wb_cpu.addr(index_size_f(wb_mem_size_c/4)+1 downto 2)))); -- word aligned
|
-- virtual read and ack latency --
|
-- virtual read and ack latency --
|
if (wb_mem_latency_c > 1) then
|
if (wb_mem_latency_c > 1) then
|
for i in 1 to wb_mem_latency_c-1 loop
|
for i in 1 to wb_mem_latency_c-1 loop
|
wb_mem.rdata(i) <= wb_mem.rdata(i-1);
|
wb_mem.rdata(i) <= wb_mem.rdata(i-1);
|
wb_mem.rb_en(i) <= wb_mem.rb_en(i-1);
|
wb_mem.rb_en(i) <= wb_mem.rb_en(i-1);
|
wb_mem.ack(i) <= wb_mem.ack(i-1) and wb_cpu.cyc;
|
wb_mem.ack(i) <= wb_mem.ack(i-1) and wb_cpu.cyc;
|
end loop;
|
end loop;
|
end if;
|
end if;
|
end if;
|
end if;
|
end process wb_mem_ram_access;
|
end process wb_mem_ram_access;
|
|
|
-- wishbone memory access? --
|
-- wishbone memory access? --
|
wb_mem.acc_en <= '1' when (wb_cpu.addr >= wb_mem_base_addr_c) and (wb_cpu.addr < std_ulogic_vector(unsigned(wb_mem_base_addr_c) + wb_mem_size_c)) else '0';
|
wb_mem.acc_en <= '1' when (wb_cpu.addr >= wb_mem_base_addr_c) and (wb_cpu.addr < std_ulogic_vector(unsigned(wb_mem_base_addr_c) + wb_mem_size_c)) else '0';
|
|
|
-- output to cpu --
|
-- output to cpu --
|
wb_cpu.rdata <= wb_mem.rdata(wb_mem_latency_c-1) when (wb_mem.rb_en(wb_mem_latency_c-1) = '1') else (others=> '0'); -- data output gate
|
wb_cpu.rdata <= wb_mem.rdata(wb_mem_latency_c-1) when (wb_mem.rb_en(wb_mem_latency_c-1) = '1') else (others=> '0'); -- data output gate
|
wb_cpu.ack <= wb_mem.ack(wb_mem_latency_c-1);
|
wb_cpu.ack <= wb_mem.ack(wb_mem_latency_c-1);
|
wb_cpu.err <= '0';
|
wb_cpu.err <= '0';
|
|
|
|
|
end neorv32_tb_rtl;
|
end neorv32_tb_rtl;
|
|
|