Subversion Repositories modular_oscilloscope

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--| Modular Oscilloscope

--| UNSL - Argentina

--|

--| File: daq.vhd

--| Version: 0.1

--| Tested in: Actel A3PE1500

--|-------------------------------------------------------------------------------------------------

--| Description:

--|   Acquisition control module. 

--|   It drives the ADC chip.

--|-------------------------------------------------------------------------------------------------

--| File history:

--|   0.01   | apr-2008 | First testing

--|   0.10   | apr-2009 | First release

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--| Copyright ® 2009, Facundo Aguilera.

--|

--| This VHDL design file is an open design; you can redistribute it and/or

--| modify it and/or implement it after contacting the author.

--| Wishbone Rev. B.3 compatible

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

--| TODO:

--|  Access to both channels in consecutive reads  

-- Esta primera versión está realizada específicamente para controlar el ADC AD9201. Otras

-- versiones podrán ser más genéricas.

-- ADR    configuración (señal config)

-- ADR+1  datos canal 1

-- ADR+2  datos canal 2

-- ADR+3  sin usar

library IEEE;

use IEEE.STD_LOGIC_1164.all;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

--use IEEE.STD_LOGIC_ARITH.all;

use IEEE.NUMERIC_STD.ALL;

--use work.adq_pgk.all;

entity daq is

  generic (

    DEFALT_CONFIG : std_logic_vector := "0000100000000000"

                                      -- bits 8 a 0       clk_pre_scaler

                                      -- bits 9           clk_pre_scaler_ena

                                      -- bit 10           adc_sleep

                                      -- bit 11           adc_chip_sel

                                      -- bits 12 a 15     sin usar

                                      -- si clk_pre_scaler_ena = 1

                                      -- frecuencia_adc = frecuencia_wbn / ((clk_pre_scaler+1)*2)

                                      -- sino frecuencia_adc = frecuencia_wbn

  );

  port(

    -- Externo

    adc_data:     in    std_logic_vector (9 downto 0);

    adc_sel:      out   std_logic;

    adc_clk:      out   std_logic;

    adc_sleep:    out   std_logic;

    adc_chip_sel: out   std_logic;

    --  Interno

    RST_I:  in  std_logic;

    CLK_I:  in  std_logic;

    DAT_I:  in  std_logic_vector (15 downto 0);

    ADR_I:  in  std_logic_vector (1 downto 0);

    CYC_I:  in  std_logic;

    STB_I:  in  std_logic;

    WE_I:   in  std_logic;

    DAT_O:  out std_logic_vector (15 downto 0);

    ACK_O:  out std_logic

  );

end daq;

architecture beh1 of daq is

  -- Tipos

  type data_array is array(0 to 2) of std_logic_vector(15 downto 0);

                --   type arr is array(0 to 3) of std_logic_vector(15 downto 0);

                -- 

                -- signal arr_a : arr;

                -- signal vec_0, vec_1, vec_2, vec_3 : std_logic vector(15 downto 0);

                -- ....

                -- arr_a(0) <= vec_0;

                -- arr_a(1) <= vec_1;

                -- ....

  -- Registros de configuración

  signal config:   std_logic_vector (15 downto 0);

  signal selector: data_array;

  -- Registros

  signal count: std_logic_vector (9 downto 0);

  -- Señales 

  signal s_adc_clk, s_adc_sleep, s_adc_chip_sel: std_logic;

  signal data_ack_ready:      std_logic; -- habilita confirmación de datos

  signal conf_ack_ready:      std_logic; -- habilita confirmación de escritura de configuración

  signal clk_pre_scaler:      std_logic_vector (8 downto 0);

  signal clk_pre_scaler_ena:  std_logic;

  --signal clk_enable: std_logic_vector (9 downto 0);

begin

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

  -- Asignaciones

  ---- Comunicación interna (Wishbone)

  selector(0) <= config;

  selector(1) <= (config'length - 1 downto adc_data'length => '0' ) & adc_data;

  selector(2) <= (config'length - 1 downto adc_data'length => '0' ) & adc_data;

  --selector(3) <= (others => '0' ); -- Sin usar

  ---- Registro de configuración config

  clk_pre_scaler <= config(8 downto 0);

  clk_pre_scaler_ena <= config(9);

  s_adc_sleep <= config(10);

  s_adc_chip_sel <= config(11);

  -- sin asignar <= config(13); para usar en otras implementaciones

  -- sin asignar <= config(14);

  -- sin asignar <= config(15);

  ---- Comunicación externa (AD)

  adc_sleep <= s_adc_sleep;

  adc_chip_sel <= s_adc_chip_sel;

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

  -- Generación de adc_clk

  process (CLK_I, clk_pre_scaler,RST_I,count, clk_pre_scaler_ena)

  begin

    if RST_I = '1' then

      count <= (others => '0');

      s_adc_clk <= '0';

    elsif clk_pre_scaler_ena = '1' then

      if CLK_I'event and CLK_I = '1' then

        count <= count + 1;

        if count = clk_pre_scaler  then

          s_adc_clk <= not(s_adc_clk);

          count <= (others => '0');

        end if;

      end if;

    else

      count <= (others => '0');

      s_adc_clk <= CLK_I;

    end if;

  end process;

  adc_clk <= s_adc_clk;

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

  -- Generación ack

  ACK_O <= CYC_I and STB_I and (data_ack_ready or conf_ack_ready);

  data_ack_ready  <=  '1' when (unsigned(count) = 0 and WE_I = '0' and unsigned(ADR_I) /= 0 and s_adc_clk = '1')

                      or (clk_pre_scaler_ena /= '1')

                  else

                      '0';

    -- count = 0 asegura que el dato actual ya fue leído

  conf_ack_ready  <=  '1' when unsigned(ADR_I) = 0  else

                      '0';

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

  -- Selección de canal

  adc_sel <=  '1' when unsigned(ADR_I) = 2 else   -- selecciona canal Q

              '0';                                -- selecciona canal I

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

  -- Lectura y escritura de datos

  ---- Generación de DAT_O

  DAT_O   <=  selector(conv_integer(ADR_I));

  ---- Almacenado de registro de configuración

  process (CLK_I, ADR_I, RST_I, DAT_I)

  begin

    if CLK_I'event and CLK_I = '1' then

      if RST_I = '1' then

        config <= DEFALT_CONFIG;

      elsif WE_I = '1' and  CYC_I = '1' and STB_I = '1' then

        if unsigned(ADR_I) = 0 then

          config <= DAT_I;

        end if;

      end if;

    end if;

  end process;

end architecture beh1;