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			322 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			VHDL
		
	
			
		
		
	
	
			322 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			VHDL
		
	
| library ieee;
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| use ieee.std_logic_1164.all;
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| use ieee.numeric_std.all;
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| 
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| library unisim;
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| use unisim.vcomponents.all;
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| 
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| library work;
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| use work.wishbone_types.all;
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| 
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| entity toplevel is
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|     generic (
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| 	MEMORY_SIZE   : integer := 16384;
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| 	RAM_INIT_FILE : string   := "firmware.hex";
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| 	CLK_FREQUENCY : positive := 100000000;
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| 	USE_LITEDRAM  : boolean  := false;
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| 	NO_BRAM       : boolean  := false;
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| 	DISABLE_FLATTEN_CORE : boolean := false;
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|         SPI_FLASH_OFFSET   : integer := 10485760;
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|         SPI_FLASH_DEF_CKDV : natural := 1;
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|         SPI_FLASH_DEF_QUAD : boolean := true;
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|         LOG_LENGTH         : natural := 2048;
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|         UART_IS_16550      : boolean := true
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| 	);
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|     port(
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| 	clk200_p   : in  std_ulogic;
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| 	clk200_n   : in  std_ulogic;
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| 
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| 	-- P2 signals used as UART
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| 	uart_rx : in std_ulogic;
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| 	uart_tx : out std_ulogic;
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| 
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| 	-- LEDs
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| 	led0	: out std_logic;
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| 	led1	: out std_logic;
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| 	led2	: out std_logic;
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| 	led3	: out std_logic;
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| 
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|         -- SPI
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|         spi_flash_cs_n   : out std_ulogic;
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|         spi_flash_mosi   : inout std_ulogic;
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|         spi_flash_miso   : inout std_ulogic;
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|         spi_flash_wp_n   : inout std_ulogic;
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|         spi_flash_hold_n : inout std_ulogic;
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| 
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| 	-- DRAM wires
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| 	ddram_a       : out std_logic_vector(15 downto 0);
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| 	ddram_ba      : out std_logic_vector(2 downto 0);
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| 	ddram_ras_n   : out std_logic;
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| 	ddram_cas_n   : out std_logic;
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| 	ddram_we_n    : out std_logic;
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| 	ddram_dm      : out std_logic_vector(1 downto 0);
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| 	ddram_dq      : inout std_logic_vector(15 downto 0);
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| 	ddram_dqs_p   : inout std_logic_vector(1 downto 0);
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| 	ddram_dqs_n   : inout std_logic_vector(1 downto 0);
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| 	ddram_clk_p   : out std_logic;
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| 	ddram_clk_n   : out std_logic;
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| 	ddram_cke     : out std_logic;
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| 	ddram_odt     : out std_logic;
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| 	ddram_reset_n : out std_logic
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| 	);
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| end entity toplevel;
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| 
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| architecture behaviour of toplevel is
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| 
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|     -- Internal clock
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|     signal ext_clk : std_ulogic;
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| 
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|     -- Reset signals:
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|     signal soc_rst : std_ulogic;
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|     signal pll_rst : std_ulogic;
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| 
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|     -- Internal clock signals:
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|     signal system_clk : std_ulogic;
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|     signal system_clk_locked : std_ulogic;
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| 
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|     -- DRAM main data wishbone connection
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|     signal wb_dram_in       : wishbone_master_out;
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|     signal wb_dram_out      : wishbone_slave_out;
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| 
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|     -- DRAM control wishbone connection
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|     signal wb_ext_io_in        : wb_io_master_out;
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|     signal wb_ext_io_out       : wb_io_slave_out;
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|     signal wb_ext_is_dram_csr  : std_ulogic;
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|     signal wb_ext_is_dram_init : std_ulogic;
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| 
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|     -- SPI flash
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|     signal spi_sck     : std_ulogic;
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|     signal spi_cs_n    : std_ulogic;
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|     signal spi_sdat_o  : std_ulogic_vector(3 downto 0);
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|     signal spi_sdat_oe : std_ulogic_vector(3 downto 0);
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|     signal spi_sdat_i  : std_ulogic_vector(3 downto 0);
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| 
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|     -- ddram clock signals as vectors
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|     signal ddram_clk_p_vec : std_logic_vector(0 downto 0);
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|     signal ddram_clk_n_vec : std_logic_vector(0 downto 0);
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| 
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|     -- Fixup various memory sizes based on generics
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|     function get_bram_size return natural is
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|     begin
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|         if USE_LITEDRAM and NO_BRAM then
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|             return 0;
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|         else
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|             return MEMORY_SIZE;
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|         end if;
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|     end function;
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| 
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|     function get_payload_size return natural is
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|     begin
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|         if USE_LITEDRAM and NO_BRAM then
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|             return MEMORY_SIZE;
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|         else
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|             return 0;
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|         end if;
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|     end function;
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| 
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|     constant BRAM_SIZE    : natural := get_bram_size;
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|     constant PAYLOAD_SIZE : natural := get_payload_size;
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| begin
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| 
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|     -- Main SoC
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|     soc0: entity work.soc
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| 	generic map(
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| 	    MEMORY_SIZE   => BRAM_SIZE,
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| 	    RAM_INIT_FILE => RAM_INIT_FILE,
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| 	    SIM           => false,
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| 	    CLK_FREQ      => CLK_FREQUENCY,
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| 	    HAS_DRAM      => USE_LITEDRAM,
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| 	    DRAM_SIZE     => 1024 * 1024 * 1024,
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|             DRAM_INIT_SIZE => PAYLOAD_SIZE,
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| 	    DISABLE_FLATTEN_CORE => DISABLE_FLATTEN_CORE,
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|             HAS_SPI_FLASH      => true,
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|             SPI_FLASH_DLINES   => 4,
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|             SPI_FLASH_OFFSET   => SPI_FLASH_OFFSET,
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|             SPI_FLASH_DEF_CKDV => SPI_FLASH_DEF_CKDV,
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|             SPI_FLASH_DEF_QUAD => SPI_FLASH_DEF_QUAD,
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|             LOG_LENGTH         => LOG_LENGTH,
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|             UART0_IS_16550     => UART_IS_16550
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| 	    )
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| 	port map (
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|             -- System signals
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| 	    system_clk        => system_clk,
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| 	    rst               => soc_rst,
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| 
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|             -- UART signals
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|             uart0_txd         => uart_tx,
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| 	    uart0_rxd         => uart_rx,
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| 
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|             -- SPI signals
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|             spi_flash_sck     => spi_sck,
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|             spi_flash_cs_n    => spi_cs_n,
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|             spi_flash_sdat_o  => spi_sdat_o,
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|             spi_flash_sdat_oe => spi_sdat_oe,
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|             spi_flash_sdat_i  => spi_sdat_i,
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| 
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|             -- DRAM wishbone
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| 	    wb_dram_in          => wb_dram_in,
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| 	    wb_dram_out         => wb_dram_out,
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| 	    wb_ext_io_in        => wb_ext_io_in,
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| 	    wb_ext_io_out       => wb_ext_io_out,
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| 	    wb_ext_is_dram_csr  => wb_ext_is_dram_csr,
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| 	    wb_ext_is_dram_init => wb_ext_is_dram_init
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| 	    );
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| 
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|     -- SPI Flash. The SPI clk needs to be fed through the STARTUPE2
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|     -- primitive of the FPGA as it's not a normal pin
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|     --
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|     spi_flash_cs_n   <= spi_cs_n;
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|     spi_flash_mosi   <= spi_sdat_o(0) when spi_sdat_oe(0) = '1' else 'Z';
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|     spi_flash_miso   <= spi_sdat_o(1) when spi_sdat_oe(1) = '1' else 'Z';
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|     spi_flash_wp_n   <= spi_sdat_o(2) when spi_sdat_oe(2) = '1' else 'Z';
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|     spi_flash_hold_n <= spi_sdat_o(3) when spi_sdat_oe(3) = '1' else 'Z';
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|     spi_sdat_i(0)    <= spi_flash_mosi;
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|     spi_sdat_i(1)    <= spi_flash_miso;
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|     spi_sdat_i(2)    <= spi_flash_wp_n;
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|     spi_sdat_i(3)    <= spi_flash_hold_n;
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| 
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|     STARTUPE2_INST: STARTUPE2
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|         port map (
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|             CLK => '0',
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|             GSR => '0',
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|             GTS => '0',
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|             KEYCLEARB => '0',
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|             PACK => '0',
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|             USRCCLKO => spi_sck,
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|             USRCCLKTS => '0',
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|             USRDONEO => '1',
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|             USRDONETS => '0'
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|             );
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| 
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|     clk200: IBUFDS
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|         port map (
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|             i  => clk200_p,
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|             ib => clk200_n,
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|             o  => ext_clk
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|         );
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| 
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|     nodram: if not USE_LITEDRAM generate
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|         signal ddram_clk_dummy : std_ulogic;
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|     begin
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| 	reset_controller: entity work.soc_reset
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| 	    generic map(
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| 		RESET_LOW => false
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| 		)
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| 	    port map(
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| 		ext_clk => ext_clk,
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| 		pll_clk => system_clk,
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| 		pll_locked_in => system_clk_locked,
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| 		ext_rst_in => '0',
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| 		pll_rst_out => pll_rst,
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| 		rst_out => soc_rst
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| 		);
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| 
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| 	clkgen: entity work.clock_generator
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| 	    generic map(
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| 		CLK_INPUT_HZ => 200000000,
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| 		CLK_OUTPUT_HZ => CLK_FREQUENCY
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| 		)
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| 	    port map(
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| 		ext_clk => ext_clk,
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| 		pll_rst_in => pll_rst,
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| 		pll_clk_out => system_clk,
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| 		pll_locked_out => system_clk_locked
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| 		);
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| 
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| 	led0 <= soc_rst;
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| 	led1 <= pll_rst;
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|         led2 <= not system_clk_locked;
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| 	led3 <= '0';
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| 
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|         -- Vivado barfs on those differential signals if left
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|         -- unconnected. So instanciate a diff. buffer and feed
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|         -- it a constant '0'.
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|         dummy_dram_clk: OBUFDS
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|             port map (
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|                 O => ddram_clk_p,
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|                 OB => ddram_clk_n,
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|                 I => ddram_clk_dummy
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|                 );
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|         ddram_clk_dummy <= '0';
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| 
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|     end generate;
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| 
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|     has_dram: if USE_LITEDRAM generate
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| 	signal dram_init_done  : std_ulogic;
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| 	signal dram_init_error : std_ulogic;
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| 	signal dram_sys_rst    : std_ulogic;
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|     begin
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| 
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| 	-- Eventually dig out the frequency from the generator
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| 	-- but for now, assert it's 100Mhz
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| 	assert CLK_FREQUENCY = 100000000;
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| 
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| 	ddram_clk_p_vec <= (others => ddram_clk_p);
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| 	ddram_clk_n_vec <= (others => ddram_clk_n);
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| 
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| 	reset_controller: entity work.soc_reset
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| 	    generic map(
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| 		RESET_LOW => false,
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|                 PLL_RESET_BITS => 18,
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|                 SOC_RESET_BITS => 1
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| 		)
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| 	    port map(
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| 		ext_clk => ext_clk,
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| 		pll_clk => system_clk,
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| 		pll_locked_in => '1',
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| 		ext_rst_in => '0',
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| 		pll_rst_out => pll_rst,
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| 		rst_out => open
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| 		);
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| 
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| 	dram: entity work.litedram_wrapper
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| 	    generic map(
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| 		DRAM_ABITS => 26,
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| 		DRAM_ALINES => 16,
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|                 DRAM_DLINES => 16,
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|                 DRAM_CKLINES => 1,
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|                 DRAM_PORT_WIDTH => 128,
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|                 PAYLOAD_FILE => RAM_INIT_FILE,
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|                 PAYLOAD_SIZE => PAYLOAD_SIZE
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| 		)
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| 	    port map(
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| 		clk_in		=> ext_clk,
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| 		rst             => pll_rst,
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| 		system_clk	=> system_clk,
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| 		system_reset	=> soc_rst,
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| 		pll_locked	=> system_clk_locked,
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| 
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| 		wb_in		=> wb_dram_in,
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| 		wb_out		=> wb_dram_out,
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| 		wb_ctrl_in	=> wb_ext_io_in,
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| 		wb_ctrl_out	=> wb_ext_io_out,
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| 		wb_ctrl_is_csr  => wb_ext_is_dram_csr,
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| 		wb_ctrl_is_init => wb_ext_is_dram_init,
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| 
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| 		init_done 	=> dram_init_done,
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| 		init_error	=> dram_init_error,
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| 
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| 		ddram_a		=> ddram_a,
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| 		ddram_ba	=> ddram_ba,
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| 		ddram_ras_n	=> ddram_ras_n,
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| 		ddram_cas_n	=> ddram_cas_n,
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| 		ddram_we_n	=> ddram_we_n,
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| 		ddram_cs_n	=> open,
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| 		ddram_dm	=> ddram_dm,
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| 		ddram_dq	=> ddram_dq,
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| 		ddram_dqs_p	=> ddram_dqs_p,
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| 		ddram_dqs_n	=> ddram_dqs_n,
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| 		ddram_clk_p	=> ddram_clk_p_vec,
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| 		ddram_clk_n	=> ddram_clk_n_vec,
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| 		ddram_cke	=> ddram_cke,
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| 		ddram_odt	=> ddram_odt,
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| 		ddram_reset_n	=> ddram_reset_n
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| 		);
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| 
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|         led0 <= soc_rst;
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| 	led1 <= pll_rst;
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| 	led2 <= not dram_init_done or dram_init_error;
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| 	led3 <= not dram_init_error; -- Make it blink ?
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|     end generate;
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| end architecture behaviour;
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