dac_control.vhd

low frequency therapy system control VHDL code

--============================================================================
-- Project 		: Low Frequency Therapy
-- Programmer	: Byungchan Son
-- Function		: 
-- Language		: VHDL
--============================================================================
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.numeric_std.all;
--============================================================================
-- 涝免仿 器飘 沥狼
--============================================================================
entity dac_control is
	port(
		-- system signal
		reset : in std_logic;
		clock : in std_logic;
		-- bus control
		p1_voltage : in std_logic_vector(7 downto 0);
		p2_voltage : in std_logic_vector(7 downto 0);
		p3_voltage : in std_logic_vector(7 downto 0);
		p4_voltage : in std_logic_vector(7 downto 0);
		-- dac
		s_din : out std_logic;
		s_sclk : out std_logic;
		s1_cs_n : out std_logic;
		s2_cs_n : out std_logic;
		s3_cs_n : out std_logic;
		s4_cs_n : out std_logic
		-- test signal
		);
end dac_control;
--============================================================================
-- 备炼 沥狼
--============================================================================
architecture dac_control_a of dac_control is
--------------------------------------------------------------------
-- 郴何 葛碘
--------------------------------------------------------------------
--------------------------------------------------------------------
-- 郴何 脚龋
--------------------------------------------------------------------
type dac_control_state is(
	idle,
	dac_start,
	dac_clock_enable,
	dac_clock_disable
	);

-- state machine signal
signal current_state, next_state : dac_control_state;
-- data signal
signal count_5ms : std_logic_vector(19 downto 0);
signal dac_flag : std_logic;
signal dac_clock_count : std_logic_vector(5 downto 0);
signal dac_clock_flag : std_logic;
signal dac_bit_count : std_logic_vector(3 downto 0);
signal t_voltage : std_logic_vector(7 downto 0);
signal channel_count : std_logic_vector(1 downto 0);
--============================================================================
-- 橇肺技辑 矫累
--============================================================================
begin
	----------------------------------------------------------------
	-- 郴何 葛碘 搬急
	----------------------------------------------------------------
	----------------------------------------------------------------
	-- 妻胶 林扁 惯积扁
	----------------------------------------------------------------
	gen_period : process(
		reset,
		clock,
		count_5ms
		)
	begin
		if(reset = '1')then
			count_5ms <= (others => '0');
			dac_flag <= '0';
		elsif(clock'event and clock = '1')then
			if(count_5ms = "01111010000100100000")then
				count_5ms <= (others => '0');
				dac_flag <= '1';
			else
				count_5ms <= count_5ms + 1;
				dac_flag <= '0';
			end if;
		end if;
	end process;
	----------------------------------------------------------------
	-- DAC
	----------------------------------------------------------------
	dac_out : process(
		reset,
		clock,
		current_state,
		next_state,
		dac_clock_count,
		dac_flag,
		channel_count,
		dac_clock_flag,
		dac_bit_count
		)
	begin
		if(reset = '1')then
			next_state <= idle;
			-- 寇何 免仿
			s_din <= '0';
			s_sclk <= '1';
			s1_cs_n <= '1';
			s2_cs_n <= '1';
			s3_cs_n <= '1';
			s4_cs_n <= '1';
			-- 郴何 脚龋
			dac_clock_count <= (others => '0');
			dac_clock_flag <= '0';
			dac_bit_count <= (others => '0');
			t_voltage <= (others => '0');
			channel_count <= (others => '0');
		elsif(clock'event and clock = '1')then
			if(dac_clock_count = "111111")then
				dac_clock_count <= (others => '0');
				dac_clock_flag <= '1';
			else
				dac_clock_count <= dac_clock_count + 1;
				dac_clock_flag <= '0';
			end if;
			case current_state is
				when idle =>
					if(dac_flag = '1')then
						if(channel_count = "00")then
							t_voltage <= p1_voltage;
						elsif(channel_count = "01")then
							t_voltage <= p2_voltage;
						elsif(channel_count = "10")then
							t_voltage <= p3_voltage;
						else
							t_voltage <= p4_voltage;
						end if;
						next_state <= dac_start;
					end if;
				when dac_start =>
					if(dac_clock_flag = '1')then
						s_sclk <= '1';
						if(channel_count = "00")then
							s1_cs_n <= '0';
						elsif(channel_count = "01")then
							s2_cs_n <= '0';
						elsif(channel_count = "10")then
							s3_cs_n <= '0';
						else
							s4_cs_n <= '0';
						end if;
						case dac_bit_count is
							when "0000" =>
								s_din <= '0';
							when "0001" =>
								s_din <= '0';
							when "0010" =>
								s_din <= '0';
							when "0011" =>
								s_din <= '0';
							when "0100" =>
								s_din <= t_voltage(7);
							when "0101" =>
								s_din <= t_voltage(6);
							when "0110" =>
								s_din <= t_voltage(5);
							when "0111" =>
								s_din <= t_voltage(4);
							when "1000" =>
								s_din <= t_voltage(3);
							when "1001" =>
								s_din <= t_voltage(2);
							when "1010" =>
								s_din <= t_voltage(1);
							when "1011" =>
								s_din <= t_voltage(0);
							when "1100" =>
								s_din <= '0';
							when "1101" =>
								s_din <= '0';
							when "1110" =>
								s_din <= '0';
							when others =>
								s_din <= '0';
						end case;
						next_state <= dac_clock_enable;
					end if;
				when dac_clock_enable =>
					if(dac_clock_flag = '1')then
						s_sclk <= '0';
						if(dac_bit_count = "1111")then
							next_state <= dac_clock_disable;
						else
							next_state <= dac_start;
						end if;
						dac_bit_count <= dac_bit_count + 1;
					end if;
				when dac_clock_disable =>
					if(dac_clock_flag = '1')then
						s_sclk <= '1';
						s1_cs_n <= '1';
						s2_cs_n <= '1';
						s3_cs_n <= '1';
						s4_cs_n <= '1';
						channel_count <= channel_count + 1;
						next_state <= idle;
					end if;
			end case;
		end if;
		current_state <= next_state;
	end process;
	----------------------------------------------------------------
	-- 肺流 脚龋
	----------------------------------------------------------------
end dac_control_a;
--============================================================================
-- 场
--============================================================================