[SPI]

- use async. FIFOs

git-svn-id: http://moon:8086/svn/vhdl/trunk@1275 cc03376c-175c-47c8-b038-4cd826a8556b

lib/spi/sim/tb_spi.fdo

@@ -5,6 +5,13 @@ if {[file exists work]} {vdel -lib work -all}
 
 vlib work
 vcom -explicit  -93 "../../misc/utils_pkg.vhd"
+vcom -explicit  -93 "../../FIFO/src/fifo_ctrl_pkg.vhd"
+vcom -explicit  -93 "../../rams/dpram_1w1r2c_ra_sim.vhd"
+vcom -explicit  -93 "../../FIFO/src/gray_counter.vhd"
+vcom -explicit  -93 "../../FIFO/src/fifo_async_ctrl.vhd"
+vcom -explicit  -93 "../../FIFO/src/fifo_async.vhd"
+vcom -explicit  -93 "../../FIFO/src/fifo_sync_ctrl.vhd"
+vcom -explicit  -93 "../../FIFO/src/fifo_sync.vhd"
 vcom -explicit  -93 "../src/spi_types.vhd"
 vcom -explicit  -93 "../src/spi_tx.vhd"
 vcom -explicit  -93 "../src/spi_rx.vhd"

lib/spi/sim/tb_spi.wdo

@@ -3,10 +3,10 @@ quietly WaveActivateNextPane {} 0
 add wave -noupdate -format Logic /tb_spi/clk
 add wave -noupdate -format Logic /tb_spi/rst
 add wave -noupdate -format Logic /tb_spi/tx_cmd_vld
-add wave -noupdate -format Logic /tb_spi/tx_cmd_ack
+add wave -noupdate -format Logic /tb_spi/tx_cmd_rdy
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/tx_cmd
 add wave -noupdate -format Logic /tb_spi/tx_din_vld
-add wave -noupdate -format Logic /tb_spi/tx_din_re
+add wave -noupdate -format Logic /tb_spi/tx_din_rdy
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/tx_din
 add wave -noupdate -format Logic /tb_spi/tx_shift_en
 add wave -noupdate -format Logic /tb_spi/tx_mosi
@@ -16,25 +16,36 @@ add wave -noupdate -format Literal /tb_spi/inst_spi_tx/word_width
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/rst
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/clk
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cmd_vld
-add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cmd_ack
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cmd_rdy
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/cmd
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/din_vld
-add wave -noupdate -format Logic /tb_spi/inst_spi_tx/din_re
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/din_rdy
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/din
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/shift_en
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/data_out
+add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/shift_reg
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/clk_out
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/xfer_count
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/data_count
+add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/word_count
 add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/cmd_reg
 add wave -noupdate -format Literal /tb_spi/inst_spi_tx/state
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/data_load_en
+add wave -noupdate -format Literal /tb_spi/inst_spi_tx/shift_cnt_pipe
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cmd_reg_we
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/xfer_count_en
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/data_count_en
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/xfer_count_busy
 add wave -noupdate -format Logic /tb_spi/inst_spi_tx/data_count_busy
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/spi_clk
+add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/cat_fifo_din
+add wave -noupdate -format Literal -radix hexadecimal /tb_spi/inst_spi_tx/cat_fifo_dout
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cat_fifo_re
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cat_fifo_we
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cat_fifo_full
+add wave -noupdate -format Logic /tb_spi/inst_spi_tx/cat_fifo_empty
 TreeUpdate [SetDefaultTree]
-WaveRestoreCursors {{Cursor 1} {5674147 ps} 0}
+WaveRestoreCursors {{Cursor 1} {6254805 ps} 0}
 configure wave -namecolwidth 197
 configure wave -valuecolwidth 131
 configure wave -justifyvalue left
@@ -48,4 +59,4 @@ configure wave -gridperiod 1
 configure wave -griddelta 40
 configure wave -timeline 0
 update
-WaveRestoreZoom {0 ps} {21 us}
+WaveRestoreZoom {5843806 ps} {8445242 ps}

lib/spi/src/spi_tx.vhd

@@ -9,21 +9,25 @@ use work.spi_types.all;
 ENTITY spi_tx IS
 	Generic
 	(
-		word_width	: natural := 32
+		word_width			: natural := 32;
+		CAT_FIFO_DEPTH		: natural := 2;
+		DATA_FIFO_DEPTH		: natural := 16
 	);
 	Port
 	(
 		rst			: in  STD_LOGIC;
 		clk			: in  STD_LOGIC;
 		cmd_vld		: in  STD_LOGIC;
-		cmd_ack		: out STD_LOGIC;
+		cmd_rdy		: out STD_LOGIC;
 		cmd			: in  cmd_t;
 		din_vld		: in  STD_LOGIC;
-		din_re		: out STD_LOGIC;
+		din_rdy		: out STD_LOGIC;
 		din			: in  unsigned(word_width-1 downto 0);
 		shift_en	: in  STD_LOGIC;
 		data_out	: out STD_LOGIC;
-		clk_out		: out STD_LOGIC
+		clk_out		: out STD_LOGIC;
+		ctrl		: in  ctrl_t;
+		status		: out status_t
 		
 	);
 END spi_tx;
@@ -43,18 +47,113 @@ ARCHITECTURE behavior OF spi_tx IS
 	signal data_count_en		: std_logic;
 	signal xfer_count_busy		: std_logic;
 	signal data_count_busy		: std_logic;
+	signal spi_clk				: std_logic := '0';
+	signal spi_clk_out			: std_logic := '0';
 	signal clk_en				: std_logic;
+
+	signal cat_fifo_din				: unsigned(to_unsigned(cmd)'length-1 downto 0);
+	signal cat_fifo_dout			: unsigned(to_unsigned(cmd)'length-1 downto 0);
+	signal cat_fifo_re				: std_logic;
+	signal cat_fifo_we				: std_logic;
+	signal cat_fifo_full			: std_logic;
+	signal cat_fifo_empty			: std_logic;
+
+	signal write_fifo_din			: unsigned(word_width-1 downto 0);
+	signal write_fifo_dout			: unsigned(word_width-1 downto 0);
+	signal write_fifo_re			: std_logic;
+	signal write_fifo_we			: std_logic;
+	signal write_fifo_full			: std_logic;
+	signal write_fifo_empty			: std_logic;
+
+	signal shift_reg				: unsigned(word_width-1 downto 0);
+	signal shift_cnt_pipe			: unsigned(word_width-1 downto 0);
+	signal data_load_en				: std_logic;
 	
 --------------------------------------------------------------------------
 begin
 
-	clk_out		<= clk and clk_en;
+	clk_out			<= spi_clk_out;
+	cat_fifo_din	<= to_unsigned(cmd);
+	write_fifo_din	<= din;
+	cmd_rdy			<= not cat_fifo_full;
+	din_rdy			<= not write_fifo_full;
+	cat_fifo_we		<= cmd_vld;
+	cmd_reg 		<= to_cmd(cat_fifo_dout);
+	data_out		<= 		shift_reg(shift_reg'left) when ctrl.msb_first = '1'	else shift_reg(shift_reg'right);
+	data_load_en	<= not data_count_en or shift_cnt_pipe(shift_cnt_pipe'left-1);
 	
 --------------------------------------------------------------------------
-proc_state_next:
+	-- Instantiate synchronous FIFO
+	inst_cat_fifo: entity work.fifo_async
+	GENERIC MAP
+	(
+		addr_width	=> NextExpBaseTwo(CAT_FIFO_DEPTH),
+		data_width	=> cmd_size
+	)
+	PORT MAP
+	(
+		rst			=>	rst,
+		clk_w		=>	clk,
+		clk_r		=>	spi_clk,
+		we			=>	cat_fifo_we,
+		re			=>	cat_fifo_re,
+		fifo_full	=>	cat_fifo_full,
+		fifo_empty	=>	cat_fifo_empty,
+		fifo_afull	=>	open,
+		fifo_aempty	=>	open,
+		data_w		=>  cat_fifo_din,
+		data_r		=>  cat_fifo_dout
+	);
+
+	-- Instantiate synchronous FIFO
+	inst_write_fifo: entity work.fifo_async
+	GENERIC MAP
+	(
+		addr_width	=> NextExpBaseTwo(DATA_FIFO_DEPTH),
+		data_width	=> word_width
+	)
+	PORT MAP
+	(
+		rst			=>	rst,
+		clk_w		=>	clk,
+		clk_r		=>	spi_clk,
+		we			=>	din_vld,
+		re			=>	write_fifo_re,
+		fifo_full	=>	write_fifo_full,
+		fifo_empty	=>	write_fifo_empty,
+		fifo_afull	=>	open,
+		fifo_aempty	=>	open,
+		data_w		=>  write_fifo_din,
+		data_r		=>  write_fifo_dout
+	);
+
+--------------------------------------------------------------------------
+proc_spi_clk_gen:
 process(clk)
 begin
 	if rising_edge(clk) then
+		spi_clk	<= not spi_clk;
+	end if;
+end process;
+
+proc_spi_clk_out_gen:
+process(clk)
+begin
+	if rising_edge(clk) then
+		if rst = '1' then
+			spi_clk_out	<= '0';
+		elsif clk_en = '0' then
+			spi_clk_out	<= ctrl.polarity;
+		else
+			spi_clk_out	<= not spi_clk_out;
+		end if;
+	end if;
+end process;
+
+proc_state_next:
+process(spi_clk)
+begin
+	if rising_edge(spi_clk) then
 		if rst = '1' then
 			state	<= idle;
 		else
@@ -64,24 +163,26 @@ begin
 end process;
 
 proc_fsm:
-process(state, cmd_vld, xfer_count_busy)
+process(state, cat_fifo_empty, xfer_count_busy)
 begin
 	state_next		<= state;
 	cmd_reg_we		<= '0';
-	cmd_ack			<= '0';
+	cat_fifo_re		<= '0';
 	xfer_count_en	<= '0';
 	data_count_en	<= '0';
 	clk_en			<= '0';
 	case state is
 	
 	when idle =>
-		cmd_ack		<= cmd_vld;
+		if cat_fifo_empty = '0' then
-		if cmd_vld = '1' then
 			cmd_reg_we	<= '1';
 			state_next	<= prepare;
 		end if;
 
 	when prepare =>
+		cat_fifo_re		<= '1';
+		write_fifo_re	<= '1';
+		clk_en			<= '1';
 		xfer_count_en	<= '1';
 		data_count_en	<= '1';
 		state_next	<= shift;
@@ -103,11 +204,11 @@ begin
 	end case;	
 end process;
 
-process(clk)
+process(spi_clk)
 begin
-	if rising_edge(clk) then
+	if rising_edge(spi_clk) then
 		if xfer_count_en = '0' then
-			xfer_count			<= cmd.xfer_size;
+			xfer_count			<= cmd_reg.xfer_size;
 			xfer_count_busy		<= '0';
 		elsif shift_en = '1' then
 			if xfer_count /= to_unsigned(0, xfer_count'length) then
@@ -120,22 +221,22 @@ begin
 	end if;
 end process;
 
-process(clk)
+process(spi_clk)
 begin
-	if rising_edge(clk) then
+	if rising_edge(spi_clk) then
-		din_re	<= '0';
 		if data_count_en = '0' then
 			word_count			<= to_unsigned(0, word_count'length);
-			data_count			<= cmd.data_size;
+			data_count			<= cmd_reg.data_size;
 			data_count_busy		<= '0';
+			shift_cnt_pipe		<= (others => '0');
 		elsif shift_en = '1' then
+			shift_cnt_pipe	<= shift_cnt_pipe(shift_cnt_pipe'left-1 downto 0) & '1';
 			if word_count /= to_unsigned(0, word_count'length) then
 				word_count			<= word_count - 1;
 			else
-				din_re				<= '1';
 				word_count			<= to_unsigned(word_width, word_count'length);
 			end if;
-			if data_count /= to_unsigned(1, data_count'length) then
+			if data_count /= to_unsigned(0, data_count'length) then
 				data_count_busy		<= '1';
 				data_count			<= data_count - 1;
 			else
@@ -145,4 +246,19 @@ begin
 	end if;
 end process;
 
+process(spi_clk)
+begin
+	if rising_edge(spi_clk) then
+		if shift_en = '1' then
+			if data_load_en = '0' then
+				shift_reg		<= write_fifo_dout;
+			elsif (ctrl.msb_first = '1') then
+				shift_reg		<= shift_reg(shift_reg'left-1 downto 0) & '0';
+			else
+				shift_reg		<= '0' & shift_reg(shift_reg'left downto 1);
+			end if;
+		end if;
+	end if;
+end process;
+
 end behavior;

lib/spi/src/spi_types.vhd

@@ -13,26 +13,56 @@ package spi_types is
 	type cmd_t is record
 		xfer_size	: unsigned(NextExpBaseTwo(XFER_SIZE_MAX)-1 downto 0);
 		data_size	: unsigned(NextExpBaseTwo(XFER_SIZE_MAX)-1 downto 0);
+	end record;	
+
+	type ctrl_t is record
 		polarity	: std_logic;
 		msb_first	: std_logic;
 	end record;	
+	
+	type status_t is record
+		dummy		: std_logic;
+	end record;	
 
 	-- Functions
+	function cmd_size return positive;
 	function to_cmd (xfer_size, data_size : natural) return cmd_t;
-
+	function to_unsigned (cmd : cmd_t) return unsigned;
+	function to_cmd (cmd : unsigned) return cmd_t;
+	
 end spi_types;
 
 package body spi_types is
 
+	function cmd_size return positive is
+	variable res : cmd_t;
+	begin
+		return res.xfer_size'length + res.data_size'length + 1 + 1;
+	end cmd_size;
+	
 	function to_cmd(xfer_size, data_size : natural) return cmd_t is
 	variable res : cmd_t;
 	begin
-		res.polarity := '1';
-		res.msb_first := '1';
 		res.xfer_size := to_unsigned(xfer_size, res.xfer_size'length);
 		res.data_size := to_unsigned(data_size, res.data_size'length);
-		
 		return res;
 	end to_cmd;	
 	
+	function to_unsigned(cmd : cmd_t) return unsigned is
+	variable res : unsigned(cmd.xfer_size'length + cmd.data_size'length + 1 + 1 -1 downto 0) := (others => '0');
+	begin
+		res(res'left downto res'left - cmd.xfer_size'length+1) := cmd.xfer_size;
+		res(res'left - cmd.xfer_size'length downto res'left - cmd.xfer_size'length - cmd.data_size'length +1) := cmd.data_size;
+		return res;
+	end to_unsigned;	
+
+	function to_cmd (cmd : unsigned) return cmd_t is
+	variable res : cmd_t;
+	begin
+		res.xfer_size := cmd(cmd'left downto cmd'left - res.xfer_size'length+1);
+		res.data_size := cmd(cmd'left - res.xfer_size'length downto cmd'left - res.xfer_size'length - res.data_size'length +1);
+		
+		return res;
+	end to_cmd;	
+
 end spi_types;

lib/spi/src/tb_spi.vhd

@@ -39,17 +39,22 @@ ARCHITECTURE behavior OF tb_spi IS
 	signal RST				: std_logic := '1';
 
 	signal tx_cmd_vld		: STD_LOGIC := '0';
-	signal tx_cmd_ack		: STD_LOGIC;
+	signal tx_cmd_rdy		: STD_LOGIC;
 	signal tx_cmd			: cmd_t;
 	signal tx_din_vld		: STD_LOGIC := '0';
-	signal tx_din_re		: STD_LOGIC;
+	signal tx_din_rdy		: STD_LOGIC;
 	signal tx_din			: unsigned(31 downto 0) := (others => '0');
 	signal tx_shift_en		: STD_LOGIC := '1';
 	signal tx_mosi			: STD_LOGIC;
 	signal tx_clk			: STD_LOGIC;
+	signal ctrl				: ctrl_t;
+	signal status			: status_t;
 
 BEGIN
 
+	ctrl.polarity		<= '0';
+	ctrl.msb_first		<= '1';
+	
 inst_spi_tx : entity work.spi_tx
 	GENERIC MAP
 	(
@@ -60,14 +65,16 @@ inst_spi_tx : entity work.spi_tx
 		rst			=> RST,
 		clk			=> CLK,
 		cmd_vld		=> tx_cmd_vld,
-		cmd_ack		=> tx_cmd_ack,
+		cmd_rdy		=> tx_cmd_rdy,
 		cmd			=> tx_cmd,
 		din_vld		=> tx_din_vld,
-		din_re		=> tx_din_re,
+		din_rdy		=> tx_din_rdy,
 		din			=> tx_din,
 		shift_en	=> tx_shift_en,
 		data_out	=> tx_mosi,
-		clk_out		=> tx_clk
+		clk_out		=> tx_clk,
+		ctrl		=> ctrl,
+		status		=> status
 		
 	);
 
@@ -86,11 +93,20 @@ STIMULUS: process
 
 		wait for 600*CLK_PERIOD;
 		RST <= '0';
+		wait for 6*CLK_PERIOD;
 		
+		wait until rising_edge(CLK);
+		tx_din			<= X"C355AAC1";
+		tx_din_vld		<= '1';
+		wait until rising_edge(CLK) and tx_din_rdy = '1';
+		tx_din			<= X"03AAFF05";
+		wait until rising_edge(CLK) and tx_din_rdy = '1';
+		tx_din_vld		<= '0';
+
 		wait until rising_edge(CLK);
 		tx_cmd		<= to_cmd(64, 48);
 		tx_cmd_vld	<= '1';
-		wait until rising_edge(CLK) and tx_cmd_ack = '1';
+		wait until rising_edge(CLK) and tx_cmd_rdy = '1';
 		tx_cmd_vld	<= '0';
 		
 		wait;