pcm.vhd.bak

PCM数据采集

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
use ieee.std_logic_arith.all;

entity PCM is
Port(
	Reset		:in  std_logic;
	PCLK		:in  std_logic;
	S_Data		:in std_logic;
	FSYNC		:in std_logic;
	Slot		:in std_logic_vector(7 downto 0);--可以最大256个时隙，固定抓某个时隙
	PCM_Data	:out  std_logic_vector(7 downto 0);
	L_Data		:out  std_logic			--上升沿锁存   
    );

end entity;

architecture ART_PCM of PCM is
--	signal MaxSlot	:std_logic_vector(7 downto 0); --根据PCLK求出当前PCM总线最大的Slot数
--	signal PCLK_8	:std_logic;
	
begin
----------------------------------
--	Process(Reset, PCLK)
--		variable count :std_logic_vector(2 downto 0);
--	begin
--		if Reset = '0' then
--			count := "000";
--		elsif PCLK'event and PCLK = '1' then
--			count := count + 1;
--			PCLK_8 <= count(2);
--		end if;
--	end process;		  
---------------------------------
--	Process(Reset, PCLK_8)
--		variable count :std_logic_vector(7 downto 0);
--		variable start :std_logic;
--	begin
--		if Reset = '0' then
--			count := (others => '0');
--			start := '0';
--		elsif PCLK_8'event and PCLK_8 = '1' then
--			if FSYNC = '1' then
--				if start = '1' then
--					MaxSlot <= count;
--				end if;
--				count := "00000000";
--				start := not start;
--			else count := count + 1; 
--			end if;
--		end if;
--	end process;
--------------------------------------------	
	Process(Reset, PCLK, FSYNC)
		variable Chunnel	:std_logic_vector(7 downto 0);--当前Slot																		
		variable Count		:std_logic_vector(2 downto 0);--记下通道内时钟
		variable databuf	:std_logic_vector(7 downto 0);	--pcmdata
		variable lastFsync 	:std_logic;	
	begin
		if Reset = '0' then
			PCM_Data <= (others =>'0');
			databuf := (others =>'0');
			Count := (others =>'0');
			Chunnel := (others =>'0'); 
			lastFsync := '0';
			L_Data <= '0';
		elsif PCLK'event and PCLK = '0' then	--下降沿采集数据
			if Chunnel = Slot + 1 and Count = "000"  then
				PCM_Data <= databuf;
				L_Data <= '1';
			end if;

			if FSYNC = '1' and lastFsync = '0' then
				Count := "000";
				Chunnel := "00000000";
				L_Data <= '0';				
			else
				databuf := databuf(6 downto 0) & S_Data;--MSB first				
				if Count = "111" then
					Chunnel := Chunnel + 1;					 
				end if;
				Count := Count + 1;
			end if;
			lastFsync := FSYNC;
		end if;
	end process;		  
-----------------------------------------------------
end ART_PCM;