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microwatt/fpga/top-nexys-video.vhdl

579 lines
20 KiB
VHDL

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
library unisim;
use unisim.vcomponents.all;
library work;
use work.wishbone_types.all;
entity toplevel is
generic (
MEMORY_SIZE : integer := 16384;
RAM_INIT_FILE : string := "firmware.hex";
RESET_LOW : boolean := true;
CLK_FREQUENCY : positive := 100000000;
HAS_FPU : boolean := true;
fetch1: Implement a simple branch target cache This implements a cache in fetch1, where each entry stores the address of a simple branch instruction (b or bc) and the target of the branch. When fetching sequentially, if the address being fetched matches the cache entry, then fetching will be redirected to the branch target. The cache has 1024 entries and is direct-mapped, i.e. indexed by bits 11..2 of the NIA. The bus from execute1 now carries information about taken and not-taken simple branches, which fetch1 uses to update the cache. The cache entry is updated for both taken and not-taken branches, with the valid bit being set if the branch was taken and cleared if the branch was not taken. If fetching is redirected to the branch target then that goes down the pipe as a predicted-taken branch, and decode1 does not do any static branch prediction. If fetching is not redirected, then the next instruction goes down the pipe as normal and decode1 does its static branch prediction. In order to make timing, the lookup of the cache is pipelined, so on each cycle the cache entry for the current NIA + 8 is read. This means that after a redirect (from decode1 or execute1), only the third and subsequent sequentially-fetched instructions will be able to be predicted. This improves the coremark value on the Arty A7-100 from about 180 to about 190 (more than 5%). The BTC is optional. Builds for the Artix 7 35-T part have it off by default because the extra ~1420 LUTs it takes mean that the design doesn't fit on the Arty A7-35 board. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
4 years ago
HAS_BTC : boolean := true;
USE_LITEDRAM : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
SPI_FLASH_OFFSET : integer := 10485760;
SPI_FLASH_DEF_CKDV : natural := 1;
SPI_FLASH_DEF_QUAD : boolean := true;
LOG_LENGTH : natural := 2048;
UART_IS_16550 : boolean := true;
USE_LITEETH : boolean := false;
USE_LITESDCARD : boolean := false
);
port(
ext_clk : in std_ulogic;
ext_rst_n : in std_ulogic;
-- UART0 signals:
uart_main_tx : out std_ulogic;
uart_main_rx : in std_ulogic;
-- LEDs
led0 : out std_ulogic;
led1 : out std_ulogic;
led2 : out std_ulogic;
led3 : out std_ulogic;
led4 : out std_ulogic;
led5 : out std_ulogic;
led6 : out std_ulogic;
led7 : out std_ulogic;
-- SPI
spi_flash_cs_n : out std_ulogic;
spi_flash_mosi : inout std_ulogic;
spi_flash_miso : inout std_ulogic;
spi_flash_wp_n : inout std_ulogic;
spi_flash_hold_n : inout std_ulogic;
-- Ethernet
eth_clocks_tx : out std_ulogic;
eth_clocks_rx : in std_ulogic;
eth_rst_n : out std_ulogic;
eth_int_n : in std_ulogic;
eth_mdio : inout std_ulogic;
eth_mdc : out std_ulogic;
eth_rx_ctl : in std_ulogic;
eth_rx_data : in std_ulogic_vector(3 downto 0);
eth_tx_ctl : out std_ulogic;
eth_tx_data : out std_ulogic_vector(3 downto 0);
-- SD card
sdcard_data : inout std_ulogic_vector(3 downto 0);
sdcard_cmd : inout std_ulogic;
sdcard_clk : out std_ulogic;
sdcard_cd : in std_ulogic;
sdcard_reset : out std_ulogic;
-- DRAM wires
ddram_a : out std_logic_vector(14 downto 0);
ddram_ba : out std_logic_vector(2 downto 0);
ddram_ras_n : out std_logic;
ddram_cas_n : out std_logic;
ddram_we_n : out std_logic;
ddram_dm : out std_logic_vector(1 downto 0);
ddram_dq : inout std_logic_vector(15 downto 0);
ddram_dqs_p : inout std_logic_vector(1 downto 0);
ddram_dqs_n : inout std_logic_vector(1 downto 0);
ddram_clk_p : out std_logic;
ddram_clk_n : out std_logic;
ddram_cke : out std_logic;
ddram_odt : out std_logic;
ddram_reset_n : out std_logic
);
end entity toplevel;
architecture behaviour of toplevel is
-- Reset signals:
signal soc_rst : std_ulogic;
signal pll_rst : std_ulogic;
-- Internal clock signals:
signal system_clk : std_ulogic;
signal system_clk_locked : std_ulogic;
-- External IOs from the SoC
signal wb_ext_io_in : wb_io_master_out;
signal wb_ext_io_out : wb_io_slave_out;
signal wb_ext_is_dram_csr : std_ulogic;
signal wb_ext_is_dram_init : std_ulogic;
signal wb_ext_is_eth : std_ulogic;
signal wb_ext_is_sdcard : std_ulogic;
-- DRAM main data wishbone connection
signal wb_dram_in : wishbone_master_out;
signal wb_dram_out : wishbone_slave_out;
-- DRAM control wishbone connection
signal wb_dram_ctrl_out : wb_io_slave_out := wb_io_slave_out_init;
-- LiteEth connection
signal ext_irq_eth : std_ulogic;
signal wb_eth_out : wb_io_slave_out := wb_io_slave_out_init;
-- LiteSDCard connection
signal ext_irq_sdcard : std_ulogic := '0';
signal wb_sdcard_out : wb_io_slave_out := wb_io_slave_out_init;
signal wb_sddma_out : wb_io_master_out := wb_io_master_out_init;
signal wb_sddma_in : wb_io_slave_out;
signal wb_sddma_nr : wb_io_master_out;
signal wb_sddma_ir : wb_io_slave_out;
-- for conversion from non-pipelined wishbone to pipelined
signal wb_sddma_stb_sent : std_ulogic;
-- SPI flash
signal spi_sck : std_ulogic;
signal spi_cs_n : std_ulogic;
signal spi_sdat_o : std_ulogic_vector(3 downto 0);
signal spi_sdat_oe : std_ulogic_vector(3 downto 0);
signal spi_sdat_i : std_ulogic_vector(3 downto 0);
-- ddram clock signals as vectors
signal ddram_clk_p_vec : std_logic_vector(0 downto 0);
signal ddram_clk_n_vec : std_logic_vector(0 downto 0);
-- Fixup various memory sizes based on generics
function get_bram_size return natural is
begin
if USE_LITEDRAM and NO_BRAM then
return 0;
else
return MEMORY_SIZE;
end if;
end function;
function get_payload_size return natural is
begin
if USE_LITEDRAM and NO_BRAM then
return MEMORY_SIZE;
else
return 0;
end if;
end function;
constant BRAM_SIZE : natural := get_bram_size;
constant PAYLOAD_SIZE : natural := get_payload_size;
begin
-- Main SoC
soc0: entity work.soc
generic map(
MEMORY_SIZE => BRAM_SIZE,
RAM_INIT_FILE => RAM_INIT_FILE,
SIM => false,
CLK_FREQ => CLK_FREQUENCY,
HAS_FPU => HAS_FPU,
fetch1: Implement a simple branch target cache This implements a cache in fetch1, where each entry stores the address of a simple branch instruction (b or bc) and the target of the branch. When fetching sequentially, if the address being fetched matches the cache entry, then fetching will be redirected to the branch target. The cache has 1024 entries and is direct-mapped, i.e. indexed by bits 11..2 of the NIA. The bus from execute1 now carries information about taken and not-taken simple branches, which fetch1 uses to update the cache. The cache entry is updated for both taken and not-taken branches, with the valid bit being set if the branch was taken and cleared if the branch was not taken. If fetching is redirected to the branch target then that goes down the pipe as a predicted-taken branch, and decode1 does not do any static branch prediction. If fetching is not redirected, then the next instruction goes down the pipe as normal and decode1 does its static branch prediction. In order to make timing, the lookup of the cache is pipelined, so on each cycle the cache entry for the current NIA + 8 is read. This means that after a redirect (from decode1 or execute1), only the third and subsequent sequentially-fetched instructions will be able to be predicted. This improves the coremark value on the Arty A7-100 from about 180 to about 190 (more than 5%). The BTC is optional. Builds for the Artix 7 35-T part have it off by default because the extra ~1420 LUTs it takes mean that the design doesn't fit on the Arty A7-35 board. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
4 years ago
HAS_BTC => HAS_BTC,
HAS_DRAM => USE_LITEDRAM,
DRAM_SIZE => 512 * 1024 * 1024,
DRAM_INIT_SIZE => PAYLOAD_SIZE,
DISABLE_FLATTEN_CORE => DISABLE_FLATTEN_CORE,
HAS_SPI_FLASH => true,
SPI_FLASH_DLINES => 4,
SPI_FLASH_OFFSET => SPI_FLASH_OFFSET,
SPI_FLASH_DEF_CKDV => SPI_FLASH_DEF_CKDV,
SPI_FLASH_DEF_QUAD => SPI_FLASH_DEF_QUAD,
LOG_LENGTH => LOG_LENGTH,
UART0_IS_16550 => UART_IS_16550,
HAS_LITEETH => USE_LITEETH,
HAS_SD_CARD => USE_LITESDCARD
)
port map (
-- System signals
system_clk => system_clk,
rst => soc_rst,
-- UART signals
uart0_txd => uart_main_tx,
uart0_rxd => uart_main_rx,
-- SPI signals
spi_flash_sck => spi_sck,
spi_flash_cs_n => spi_cs_n,
spi_flash_sdat_o => spi_sdat_o,
spi_flash_sdat_oe => spi_sdat_oe,
spi_flash_sdat_i => spi_sdat_i,
-- External interrupts
ext_irq_eth => ext_irq_eth,
ext_irq_sdcard => ext_irq_sdcard,
-- IO wishbone
wb_dram_in => wb_dram_in,
wb_dram_out => wb_dram_out,
wb_ext_io_in => wb_ext_io_in,
wb_ext_io_out => wb_ext_io_out,
wb_ext_is_dram_csr => wb_ext_is_dram_csr,
wb_ext_is_dram_init => wb_ext_is_dram_init,
wb_ext_is_eth => wb_ext_is_eth,
wb_ext_is_sdcard => wb_ext_is_sdcard,
-- DMA wishbone
wishbone_dma_in => wb_sddma_in,
wishbone_dma_out => wb_sddma_out
);
-- SPI Flash. The SPI clk needs to be fed through the STARTUPE2
-- primitive of the FPGA as it's not a normal pin
--
spi_flash_cs_n <= spi_cs_n;
spi_flash_mosi <= spi_sdat_o(0) when spi_sdat_oe(0) = '1' else 'Z';
spi_flash_miso <= spi_sdat_o(1) when spi_sdat_oe(1) = '1' else 'Z';
spi_flash_wp_n <= spi_sdat_o(2) when spi_sdat_oe(2) = '1' else 'Z';
spi_flash_hold_n <= spi_sdat_o(3) when spi_sdat_oe(3) = '1' else 'Z';
spi_sdat_i(0) <= spi_flash_mosi;
spi_sdat_i(1) <= spi_flash_miso;
spi_sdat_i(2) <= spi_flash_wp_n;
spi_sdat_i(3) <= spi_flash_hold_n;
STARTUPE2_INST: STARTUPE2
port map (
CLK => '0',
GSR => '0',
GTS => '0',
KEYCLEARB => '0',
PACK => '0',
USRCCLKO => spi_sck,
USRCCLKTS => '0',
USRDONEO => '1',
USRDONETS => '0'
);
nodram: if not USE_LITEDRAM generate
signal ddram_clk_dummy : std_ulogic;
begin
reset_controller: entity work.soc_reset
generic map(
RESET_LOW => RESET_LOW
)
port map(
ext_clk => ext_clk,
pll_clk => system_clk,
pll_locked_in => system_clk_locked,
ext_rst_in => ext_rst_n,
pll_rst_out => pll_rst,
rst_out => soc_rst
);
clkgen: entity work.clock_generator
generic map(
CLK_INPUT_HZ => 100000000,
CLK_OUTPUT_HZ => CLK_FREQUENCY
)
port map(
ext_clk => ext_clk,
pll_rst_in => pll_rst,
pll_clk_out => system_clk,
pll_locked_out => system_clk_locked
);
led0 <= '1';
led1 <= not soc_rst;
led2 <= '0';
-- Vivado barfs on those differential signals if left
-- unconnected. So instanciate a diff. buffer and feed
-- it a constant '0'.
dummy_dram_clk: OBUFDS
port map (
O => ddram_clk_p,
OB => ddram_clk_n,
I => ddram_clk_dummy
);
ddram_clk_dummy <= '0';
end generate;
has_dram: if USE_LITEDRAM generate
signal dram_init_done : std_ulogic;
signal dram_init_error : std_ulogic;
signal dram_sys_rst : std_ulogic;
begin
-- Eventually dig out the frequency from the generator
-- but for now, assert it's 100Mhz
assert CLK_FREQUENCY = 100000000;
reset_controller: entity work.soc_reset
generic map(
RESET_LOW => RESET_LOW,
PLL_RESET_BITS => 18,
SOC_RESET_BITS => 1
)
port map(
ext_clk => ext_clk,
pll_clk => system_clk,
pll_locked_in => '1',
ext_rst_in => ext_rst_n,
pll_rst_out => pll_rst,
rst_out => open
);
-- Generate SoC reset
soc_rst_gen: process(system_clk)
begin
if ext_rst_n = '0' then
soc_rst <= '1';
elsif rising_edge(system_clk) then
soc_rst <= dram_sys_rst or not system_clk_locked;
end if;
end process;
ddram_clk_p_vec <= (others => ddram_clk_p);
ddram_clk_n_vec <= (others => ddram_clk_n);
dram: entity work.litedram_wrapper
generic map(
DRAM_ABITS => 25,
DRAM_ALINES => 15,
DRAM_DLINES => 16,
DRAM_CKLINES => 1,
DRAM_PORT_WIDTH => 128,
PAYLOAD_FILE => RAM_INIT_FILE,
PAYLOAD_SIZE => PAYLOAD_SIZE
)
port map(
clk_in => ext_clk,
rst => pll_rst,
system_clk => system_clk,
system_reset => dram_sys_rst,
pll_locked => system_clk_locked,
wb_in => wb_dram_in,
wb_out => wb_dram_out,
wb_ctrl_in => wb_ext_io_in,
wb_ctrl_out => wb_dram_ctrl_out,
wb_ctrl_is_csr => wb_ext_is_dram_csr,
wb_ctrl_is_init => wb_ext_is_dram_init,
init_done => dram_init_done,
init_error => dram_init_error,
ddram_a => ddram_a,
ddram_ba => ddram_ba,
ddram_ras_n => ddram_ras_n,
ddram_cas_n => ddram_cas_n,
ddram_we_n => ddram_we_n,
ddram_cs_n => open,
ddram_dm => ddram_dm,
ddram_dq => ddram_dq,
ddram_dqs_p => ddram_dqs_p,
ddram_dqs_n => ddram_dqs_n,
ddram_clk_p => ddram_clk_p_vec,
ddram_clk_n => ddram_clk_n_vec,
ddram_cke => ddram_cke,
ddram_odt => ddram_odt,
ddram_reset_n => ddram_reset_n
);
led0 <= not dram_init_done;
led1 <= dram_init_error; -- Make it blink ?
led2 <= dram_init_done and not dram_init_error;
end generate;
has_liteeth : if USE_LITEETH generate
component liteeth_core port (
sys_clock : in std_ulogic;
sys_reset : in std_ulogic;
rgmii_eth_clocks_tx : out std_ulogic;
rgmii_eth_clocks_rx : in std_ulogic;
rgmii_eth_rst_n : out std_ulogic;
rgmii_eth_int_n : in std_ulogic;
rgmii_eth_mdio : inout std_ulogic;
rgmii_eth_mdc : out std_ulogic;
rgmii_eth_rx_ctl : in std_ulogic;
rgmii_eth_rx_data : in std_ulogic_vector(3 downto 0);
rgmii_eth_tx_ctl : out std_ulogic;
rgmii_eth_tx_data : out std_ulogic_vector(3 downto 0);
wishbone_adr : in std_ulogic_vector(29 downto 0);
wishbone_dat_w : in std_ulogic_vector(31 downto 0);
wishbone_dat_r : out std_ulogic_vector(31 downto 0);
wishbone_sel : in std_ulogic_vector(3 downto 0);
wishbone_cyc : in std_ulogic;
wishbone_stb : in std_ulogic;
wishbone_ack : out std_ulogic;
wishbone_we : in std_ulogic;
wishbone_cti : in std_ulogic_vector(2 downto 0);
wishbone_bte : in std_ulogic_vector(1 downto 0);
wishbone_err : out std_ulogic;
interrupt : out std_ulogic
);
end component;
signal wb_eth_cyc : std_ulogic;
signal wb_eth_adr : std_ulogic_vector(29 downto 0);
begin
liteeth : liteeth_core
port map(
sys_clock => system_clk,
sys_reset => soc_rst,
rgmii_eth_clocks_tx => eth_clocks_tx,
rgmii_eth_clocks_rx => eth_clocks_rx,
rgmii_eth_rst_n => eth_rst_n,
rgmii_eth_int_n => eth_int_n,
rgmii_eth_mdio => eth_mdio,
rgmii_eth_mdc => eth_mdc,
rgmii_eth_rx_ctl => eth_rx_ctl,
rgmii_eth_rx_data => eth_rx_data,
rgmii_eth_tx_ctl => eth_tx_ctl,
rgmii_eth_tx_data => eth_tx_data,
wishbone_adr => wb_eth_adr,
wishbone_dat_w => wb_ext_io_in.dat,
wishbone_dat_r => wb_eth_out.dat,
wishbone_sel => wb_ext_io_in.sel,
wishbone_cyc => wb_eth_cyc,
wishbone_stb => wb_ext_io_in.stb,
wishbone_ack => wb_eth_out.ack,
wishbone_we => wb_ext_io_in.we,
wishbone_cti => "000",
wishbone_bte => "00",
wishbone_err => open,
interrupt => ext_irq_eth
);
-- Gate cyc with "chip select" from soc
wb_eth_cyc <= wb_ext_io_in.cyc and wb_ext_is_eth;
-- Remove top address bits as liteeth decoder doesn't know about them
wb_eth_adr <= x"000" & "000" & wb_ext_io_in.adr(14 downto 0);
-- LiteETH isn't pipelined
wb_eth_out.stall <= not wb_eth_out.ack;
end generate;
no_liteeth : if not USE_LITEETH generate
ext_irq_eth <= '0';
end generate;
-- SD card
has_sdcard : if USE_LITESDCARD generate
component litesdcard_core port (
clk : in std_ulogic;
rst : in std_ulogic;
-- wishbone for accessing control registers
wb_ctrl_adr : in std_ulogic_vector(29 downto 0);
wb_ctrl_dat_w : in std_ulogic_vector(31 downto 0);
wb_ctrl_dat_r : out std_ulogic_vector(31 downto 0);
wb_ctrl_sel : in std_ulogic_vector(3 downto 0);
wb_ctrl_cyc : in std_ulogic;
wb_ctrl_stb : in std_ulogic;
wb_ctrl_ack : out std_ulogic;
wb_ctrl_we : in std_ulogic;
wb_ctrl_cti : in std_ulogic_vector(2 downto 0);
wb_ctrl_bte : in std_ulogic_vector(1 downto 0);
wb_ctrl_err : out std_ulogic;
-- wishbone for SD card core to use for DMA
wb_dma_adr : out std_ulogic_vector(29 downto 0);
wb_dma_dat_w : out std_ulogic_vector(31 downto 0);
wb_dma_dat_r : in std_ulogic_vector(31 downto 0);
wb_dma_sel : out std_ulogic_vector(3 downto 0);
wb_dma_cyc : out std_ulogic;
wb_dma_stb : out std_ulogic;
wb_dma_ack : in std_ulogic;
wb_dma_we : out std_ulogic;
wb_dma_cti : out std_ulogic_vector(2 downto 0);
wb_dma_bte : out std_ulogic_vector(1 downto 0);
wb_dma_err : in std_ulogic;
-- connections to SD card
sdcard_data : inout std_ulogic_vector(3 downto 0);
sdcard_cmd : inout std_ulogic;
sdcard_clk : out std_ulogic;
sdcard_cd : in std_ulogic;
irq : out std_ulogic
);
end component;
signal wb_sdcard_cyc : std_ulogic;
signal wb_sdcard_adr : std_ulogic_vector(29 downto 0);
begin
litesdcard : litesdcard_core
port map (
clk => system_clk,
rst => soc_rst,
wb_ctrl_adr => wb_sdcard_adr,
wb_ctrl_dat_w => wb_ext_io_in.dat,
wb_ctrl_dat_r => wb_sdcard_out.dat,
wb_ctrl_sel => wb_ext_io_in.sel,
wb_ctrl_cyc => wb_sdcard_cyc,
wb_ctrl_stb => wb_ext_io_in.stb,
wb_ctrl_ack => wb_sdcard_out.ack,
wb_ctrl_we => wb_ext_io_in.we,
wb_ctrl_cti => "000",
wb_ctrl_bte => "00",
wb_ctrl_err => open,
wb_dma_adr => wb_sddma_nr.adr,
wb_dma_dat_w => wb_sddma_nr.dat,
wb_dma_dat_r => wb_sddma_ir.dat,
wb_dma_sel => wb_sddma_nr.sel,
wb_dma_cyc => wb_sddma_nr.cyc,
wb_dma_stb => wb_sddma_nr.stb,
wb_dma_ack => wb_sddma_ir.ack,
wb_dma_we => wb_sddma_nr.we,
wb_dma_cti => open,
wb_dma_bte => open,
wb_dma_err => '0',
sdcard_data => sdcard_data,
sdcard_cmd => sdcard_cmd,
sdcard_clk => sdcard_clk,
sdcard_cd => sdcard_cd,
irq => ext_irq_sdcard
);
-- Gate cyc with chip select from SoC
wb_sdcard_cyc <= wb_ext_io_in.cyc and wb_ext_is_sdcard;
wb_sdcard_adr <= x"0000" & wb_ext_io_in.adr(13 downto 0);
wb_sdcard_out.stall <= not wb_sdcard_out.ack;
sdcard_reset <= '0';
-- Convert non-pipelined DMA wishbone to pipelined by suppressing
-- non-acknowledged strobes
process(system_clk)
begin
if rising_edge(system_clk) then
wb_sddma_out <= wb_sddma_nr;
if wb_sddma_stb_sent = '1' or
(wb_sddma_out.stb = '1' and wb_sddma_in.stall = '0') then
wb_sddma_out.stb <= '0';
end if;
if wb_sddma_nr.cyc = '0' or wb_sddma_ir.ack = '1' then
wb_sddma_stb_sent <= '0';
elsif wb_sddma_in.stall = '0' then
wb_sddma_stb_sent <= wb_sddma_nr.stb;
end if;
wb_sddma_ir <= wb_sddma_in;
end if;
end process;
end generate;
no_sdcard : if not USE_LITESDCARD generate
sdcard_reset <= '1';
end generate;
-- Mux WB response on the IO bus
wb_ext_io_out <= wb_eth_out when wb_ext_is_eth = '1' else
wb_sdcard_out when wb_ext_is_sdcard = '1' else
wb_dram_ctrl_out;
led4 <= system_clk_locked;
led5 <= '1';
led6 <= not soc_rst;
led7 <= '0';
end architecture behaviour;