Subversion Repositories lpd8806

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-- LPD8806 RGB LED string driver FPGA

--------------------------------------

--

-- Capable of lighting up a string of

-- colorful LEDs with any desired

-- colors, at a specific update rate.

--

--------------------------------------

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use ieee.math_real.all;

use ieee.std_logic_textio.all;

library work;

use work.lpd8806_pack.all;

use work.convert_pack.all;

entity fpga is

  port (

    -- System Clock & Reset_n

    sys_clk      : in    std_logic; -- FPGA clock

    sys_rst_n    : in    std_logic;

    -- lpd8806 I/O

    rgb_led_clk  : out   std_logic;

    rgb_led_dat  : out   std_logic;

    -- Standardized Board Inputs / Outputs

    switch       : in    unsigned(7 downto 0);

    led          : out   unsigned(7 downto 0)

  );

end fpga;

architecture beh of fpga is

  -- Constants

  constant SYS_CLK_RATE    : real :=  25000000.0; -- The clock rate at which the FPGA runs

  --Component Declarations

  ----------------------------------------------------------------------------

  --Internal signal declarations

    -- Reset signals (can be asserted through syscon)

  signal fpga_rst_n        : std_logic;

  -----------------------------------------------

  -- Board Input & Output related

  signal switch_l         : unsigned(7 downto 0);

  -- Colorful Display related

  signal lpd8806_c_adr    : unsigned(7 downto 0);

  signal lpd8806_c_dat    : unsigned(6 downto 0);

  signal lpd8806_sclk     : std_logic;

  signal lpd8806_sdat     : std_logic;

  -- Test and Debug related

  signal spi_sclk         : std_logic;

  signal spi_sdat         : std_logic;

-------------------------------------------------

begin

  -- Invert switch inputs.  On this board, "switch on" is a low logic level.

  switch_l <= not (switch);

  -- System clock enable currently not used.

  sys_clk_en <= '1';

  -- Assign LED outputs.  These LEDs illuminate when driven low.

  led <= switch;

  ------------------------------

  -- Drive lpd8806 RGB LED string

  lpd8806_0 : lpd8806_LED_chain_driver

    generic map(

      SCLK_FREQ    => 2000000.0, -- Desired lpd8806 serial clock frequency

      UPDATE_FREQ  => 20.0,      -- Desired LED chain update frequency

      SYS_CLK_RATE => SYS_CLK_RATE,  -- underlying clock rate

      N_LEDS       => 8           -- Number of LEDs in chain

    )

    port map(

      -- System Clock, Reset and Clock Enable

      sys_rst_n   => sys_rst_n,

      sys_clk     => sys_clk,

      sys_clk_en  => sys_clk_en,

      -- Selection of color information

      c_adr_o     => lpd8806_c_adr,

      c_dat_i     => lpd8806_c_dat,

      -- Output

      sclk_o      => lpd8806_sclk,

      sdat_o      => lpd8806_sdat

    );

  with to_integer(lpd8806_c_adr) select

    lpd8806_c_dat <=

                             -- LED 0

      "1111111"            when 16#00#, -- Green

      "0000000"            when 16#01#, -- Red

      "0000000"            when 16#02#, -- Blue

                             -- LED 1

      "1111111"            when 16#04#, -- Green

      "1111111"            when 16#05#, -- Red

      "0000000"            when 16#06#, -- Blue

                             -- LED 2

      "0000000"            when 16#08#, -- Green

      "1111111"            when 16#09#, -- Red

      "0000000"            when 16#0A#, -- Blue

                             -- LED 3

      "0000000"            when 16#0C#, -- Green

      "0000000"            when 16#0D#, -- Red

      "1111111"            when 16#0E#, -- Blue

                             -- LED 4

      "0000000"            when 16#10#, -- Green

      switch_l(6 downto 0) when 16#11#, -- Red

      "0000000"            when 16#12#, -- Blue

                             -- LED 5

      switch_l(6 downto 0) when 16#14#, -- Green

      "0000000"            when 16#15#, -- Red

      "0000000"            when 16#16#, -- Blue

                             -- LED 6

      "0000000"            when 16#18#, -- Green

      "0000000"            when 16#19#, -- Red

      switch_l(6 downto 0) when 16#1A#, -- Blue

                             -- LED 7

      switch_l(6 downto 0) when 16#1C#, -- Green

      switch_l(6 downto 0) when 16#1D#, -- Red

      switch_l(6 downto 0) when 16#1E#, -- Blue

      "1111111"           when others;

  ------------------------------

  -- Debug lpd8806 RGB LED string

  spi_writer_0 : spi_byte_writer

    generic map(

      SCLK_FREQ    => 2000000.0,    -- Desired lpd8806 serial clock frequency

      SYS_CLK_RATE => SYS_CLK_RATE  -- underlying clock rate

    )

    port map(

      -- System Clock, Reset and Clock Enable

      sys_rst_n   => sys_rst_n,

      sys_clk     => sys_clk,

      sys_clk_en  => sys_clk_en,

      -- Data to send.

      sel_i       => sel_led,

      we_i        => bus_we,

      dat_i       => bus_dat_wr(7 downto 0),

      -- Output

      ssel_o      => open,

      sclk_o      => spi_sclk,

      sdat_o      => spi_sdat

    );

  rgb_led_clk <= lpd8806_sclk when switch_l(7)='0' else spi_sclk;

  rgb_led_dat <= lpd8806_sdat when switch_l(7)='0' else spi_sdat;

end beh;