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antonblanchard.microwatt/fpga/top-arty.vhdl
Paul Mackerras 45cd8f4fc3 core: Add support for floating-point loads and stores 
This extends the register file so it can hold FPR values, and
implements the FP loads and stores that do not require conversion
between single and double precision.

We now have the FP, FE0 and FE1 bits in MSR.  FP loads and stores
cause a FP unavailable interrupt if MSR[FP] = 0.

The FPU facilities are optional and their presence is controlled by
the HAS_FPU generic passed down from the top-level board file.  It
defaults to true for all except the A7-35 boards.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2020-09-03 15:14:17 +10:00

549 lines
19 KiB
VHDL
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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;
USE_LITEDRAM : boolean := false;
NO_BRAM : boolean := false;
DISABLE_FLATTEN_CORE : boolean := false;
SCLK_STARTUPE2 : boolean := false;
SPI_FLASH_OFFSET : integer := 4194304;
SPI_FLASH_DEF_CKDV : natural := 1;
SPI_FLASH_DEF_QUAD : boolean := true;
LOG_LENGTH : natural := 512;
USE_LITEETH : boolean := false;
UART_IS_16550 : boolean := false;
HAS_UART1 : boolean := true
);
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;
-- UART1 signals:
uart_pmod_tx : out std_ulogic;
uart_pmod_rx : in std_ulogic;
uart_pmod_cts_n : in std_ulogic;
uart_pmod_rts_n : out std_ulogic;
-- LEDs
led0_b : out std_ulogic;
led0_g : out std_ulogic;
led0_r : 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_clk : 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_ref_clk : out std_ulogic;
eth_clocks_tx : in std_ulogic;
eth_clocks_rx : in std_ulogic;
eth_rst_n : out std_ulogic;
eth_mdio : inout std_ulogic;
eth_mdc : out std_ulogic;
eth_rx_dv : in std_ulogic;
eth_rx_er : in std_ulogic;
eth_rx_data : in std_ulogic_vector(3 downto 0);
eth_tx_en : out std_ulogic;
eth_tx_data : out std_ulogic_vector(3 downto 0);
eth_col : in std_ulogic;
eth_crs : in std_ulogic;
-- DRAM wires
ddram_a : out std_ulogic_vector(13 downto 0);
ddram_ba : out std_ulogic_vector(2 downto 0);
ddram_ras_n : out std_ulogic;
ddram_cas_n : out std_ulogic;
ddram_we_n : out std_ulogic;
ddram_cs_n : out std_ulogic;
ddram_dm : out std_ulogic_vector(1 downto 0);
ddram_dq : inout std_ulogic_vector(15 downto 0);
ddram_dqs_p : inout std_ulogic_vector(1 downto 0);
ddram_dqs_n : inout std_ulogic_vector(1 downto 0);
ddram_clk_p : out std_ulogic;
ddram_clk_n : out std_ulogic;
ddram_cke : out std_ulogic;
ddram_odt : out std_ulogic;
ddram_reset_n : out std_ulogic
);
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;
signal eth_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;
-- 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;
-- Control/status
signal core_alt_reset : std_ulogic;
-- Status LED
signal led0_b_pwm : std_ulogic;
signal led0_r_pwm : std_ulogic;
signal led0_g_pwm : std_ulogic;
-- Dumb PWM for the LEDs, those RGB LEDs are too bright otherwise
signal pwm_counter : std_ulogic_vector(8 downto 0);
-- 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);
-- 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,
HAS_DRAM => USE_LITEDRAM,
DRAM_SIZE => 256 * 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,
HAS_LITEETH => USE_LITEETH,
UART0_IS_16550 => UART_IS_16550,
HAS_UART1 => HAS_UART1
)
port map (
-- System signals
system_clk => system_clk,
rst => soc_rst,
-- UART signals
uart0_txd => uart_main_tx,
uart0_rxd => uart_main_rx,
-- UART1 signals
uart1_txd => uart_pmod_tx,
uart1_rxd => uart_pmod_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,
-- DRAM 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,
alt_reset => core_alt_reset
);
uart_pmod_rts_n <= '0';
-- SPI Flash
--
-- Note: Unlike many other boards, the SPI flash on the Arty has
-- an actual pin to generate the clock and doesn't require to use
-- the STARTUPE2 primitive.
--
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;
spi_sclk_startupe2: if SCLK_STARTUPE2 generate
spi_flash_clk <= 'Z';
STARTUPE2_INST: STARTUPE2
port map (
CLK => '0',
GSR => '0',
GTS => '0',
KEYCLEARB => '0',
PACK => '0',
USRCCLKO => spi_sck,
USRCCLKTS => '0',
USRDONEO => '1',
USRDONETS => '0'
);
end generate;
spi_direct_sclk: if not SCLK_STARTUPE2 generate
spi_flash_clk <= spi_sck;
end generate;
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 and eth_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_b_pwm <= '1';
led0_r_pwm <= '1';
led0_g_pwm <= '0';
core_alt_reset <= '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;
signal rst_gen_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 => eth_clk_locked,
ext_rst_in => ext_rst_n,
pll_rst_out => pll_rst,
rst_out => rst_gen_rst
);
-- 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 eth_clk_locked or not system_clk_locked;
end if;
end process;
dram: entity work.litedram_wrapper
generic map(
DRAM_ABITS => 24,
DRAM_ALINES => 14,
DRAM_DLINES => 16,
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,
core_alt_reset => core_alt_reset,
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 => ddram_cs_n,
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,
ddram_clk_n => ddram_clk_n,
ddram_cke => ddram_cke,
ddram_odt => ddram_odt,
ddram_reset_n => ddram_reset_n
);
led0_b_pwm <= not dram_init_done;
led0_r_pwm <= dram_init_error;
led0_g_pwm <= 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;
mii_eth_clocks_tx : in std_ulogic;
mii_eth_clocks_rx : in std_ulogic;
mii_eth_rst_n : out std_ulogic;
mii_eth_mdio : in std_ulogic;
mii_eth_mdc : out std_ulogic;
mii_eth_rx_dv : in std_ulogic;
mii_eth_rx_er : in std_ulogic;
mii_eth_rx_data : in std_ulogic_vector(3 downto 0);
mii_eth_tx_en : out std_ulogic;
mii_eth_tx_data : out std_ulogic_vector(3 downto 0);
mii_eth_col : in std_ulogic;
mii_eth_crs : in std_ulogic;
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);
-- Change this to use a PLL instead of a BUFR to generate the 25Mhz
-- reference clock to the PHY.
constant USE_PLL : boolean := false;
begin
eth_use_pll: if USE_PLL generate
signal eth_clk_25 : std_ulogic;
signal eth_clkfb : std_ulogic;
begin
pll_eth : PLLE2_BASE
generic map (
BANDWIDTH => "OPTIMIZED",
CLKFBOUT_MULT => 16,
CLKIN1_PERIOD => 10.0,
CLKOUT0_DIVIDE => 64,
DIVCLK_DIVIDE => 1,
STARTUP_WAIT => "FALSE")
port map (
CLKOUT0 => eth_clk_25,
CLKOUT1 => open,
CLKOUT2 => open,
CLKOUT3 => open,
CLKOUT4 => open,
CLKOUT5 => open,
CLKFBOUT => eth_clkfb,
LOCKED => eth_clk_locked,
CLKIN1 => ext_clk,
PWRDWN => '0',
RST => pll_rst,
CLKFBIN => eth_clkfb);
eth_clk_buf: BUFG
port map (
I => eth_clk_25,
O => eth_ref_clk
);
end generate;
eth_use_bufr: if not USE_PLL generate
eth_clk_div: BUFR
generic map (
BUFR_DIVIDE => "4"
)
port map (
I => system_clk,
O => eth_ref_clk,
CE => '1',
CLR => '0'
);
eth_clk_locked <= '1';
end generate;
liteeth : liteeth_core
port map(
sys_clock => system_clk,
sys_reset => soc_rst,
mii_eth_clocks_tx => eth_clocks_tx,
mii_eth_clocks_rx => eth_clocks_rx,
mii_eth_rst_n => eth_rst_n,
mii_eth_mdio => eth_mdio,
mii_eth_mdc => eth_mdc,
mii_eth_rx_dv => eth_rx_dv,
mii_eth_rx_er => eth_rx_er,
mii_eth_rx_data => eth_rx_data,
mii_eth_tx_en => eth_tx_en,
mii_eth_tx_data => eth_tx_data,
mii_eth_col => eth_col,
mii_eth_crs => eth_crs,
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(16 downto 2);
-- LiteETH isn't pipelined
wb_eth_out.stall <= not wb_eth_out.ack;
end generate;
no_liteeth : if not USE_LITEETH generate
eth_clk_locked <= '1';
ext_irq_eth <= '0';
end generate;
-- Mux WB response on the IO bus
wb_ext_io_out <= wb_eth_out when wb_ext_is_eth = '1' else wb_dram_ctrl_out;
leds_pwm : process(system_clk)
begin
if rising_edge(system_clk) then
pwm_counter <= std_ulogic_vector(signed(pwm_counter) + 1);
if pwm_counter(8 downto 4) = "00000" then
led0_b <= led0_b_pwm;
led0_r <= led0_r_pwm;
led0_g <= led0_g_pwm;
else
led0_b <= '0';
led0_r <= '0';
led0_g <= '0';
end if;
end if;
end process;
led4 <= system_clk_locked;
led5 <= eth_clk_locked;
led6 <= not soc_rst;
led7 <= not spi_flash_cs_n;
end architecture behaviour;
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