| Line 40... |
Line 40... |
-- Revision History
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-- Revision History
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-- Author Date Change
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-- Author Date Change
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------------------ -------- ---------------------------------------------------
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------------------ -------- ---------------------------------------------------
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-- Seth Henry 12/19/19 Design Start
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-- Seth Henry 12/19/19 Design Start
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-- Seth Henry 04/16/20 Modified to use Open8 bus record
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-- Seth Henry 04/16/20 Modified to use Open8 bus record
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-- Seth Henry 05/18/20 Added write qualification input
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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_unsigned.all;
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use ieee.std_logic_unsigned.all;
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| Line 54... |
Line 55... |
generic(
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generic(
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Address : ADDRESS_TYPE
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Address : ADDRESS_TYPE
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);
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);
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port(
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port(
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Open8_Bus : in OPEN8_BUS_TYPE;
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Open8_Bus : in OPEN8_BUS_TYPE;
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Write_Qual : in std_logic := '1';
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Rd_Data : out DATA_TYPE
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Rd_Data : out DATA_TYPE
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);
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);
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end entity;
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end entity;
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architecture behave of o8_crc16_ccitt is
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architecture behave of o8_crc16_ccitt is
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| Line 69... |
Line 71... |
(others => '0');
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(others => '0');
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constant User_Addr : std_logic_vector(15 downto 2)
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constant User_Addr : std_logic_vector(15 downto 2)
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:= Address(15 downto 2);
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:= Address(15 downto 2);
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alias Comp_Addr is Open8_Bus.Address(15 downto 2);
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alias Comp_Addr is Open8_Bus.Address(15 downto 2);
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alias Reg_Addr is Open8_Bus.Address(1 downto 0);
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signal Reg_Sel : std_logic_vector(1 downto 0) :=
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(others => '0');
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signal Addr_Match : std_logic;
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signal Addr_Match : std_logic;
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signal Wr_En : std_logic;
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signal Wr_Data_q : DATA_TYPE := (others => '0');
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alias Reg_Sel_d is Open8_Bus.Address(1 downto 0);
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signal Rd_En : std_logic;
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signal Reg_Sel_q : std_logic_vector(1 downto 0) := "00";
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signal Wr_En_d : std_logic := '0';
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signal Wr_En_q : std_logic := '0';
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alias Wr_Data_d is Open8_Bus.Wr_Data;
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signal Wr_Data_q : DATA_TYPE := x"00";
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signal Rd_En_d : std_logic := '0';
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signal Rd_En_q : std_logic := '0';
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signal Next_Byte : DATA_TYPE := (others => '0');
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signal Next_Byte : DATA_TYPE := (others => '0');
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signal Byte_Count : DATA_TYPE := (others => '0');
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signal Byte_Count : DATA_TYPE := (others => '0');
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signal Calc_En : std_logic := '0';
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signal Calc_En : std_logic := '0';
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| Line 92... |
Line 97... |
(others => '0');
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(others => '0');
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begin
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begin
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Addr_Match <= '1' when Comp_Addr = User_Addr else '0';
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Addr_Match <= '1' when Comp_Addr = User_Addr else '0';
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Wr_En_d <= Addr_Match and Open8_Bus.Wr_En and Write_Qual;
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Rd_En_d <= Addr_Match and Open8_Bus.Rd_En;
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Exr(0) <= Reg(0) xor Data(0);
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Exr(0) <= Reg(0) xor Data(0);
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Exr(1) <= Reg(1) xor Data(1);
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Exr(1) <= Reg(1) xor Data(1);
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Exr(2) <= Reg(2) xor Data(2);
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Exr(2) <= Reg(2) xor Data(2);
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Exr(3) <= Reg(3) xor Data(3);
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Exr(3) <= Reg(3) xor Data(3);
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| Line 105... |
Line 112... |
Exr(7) <= Reg(7) xor Data(7);
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Exr(7) <= Reg(7) xor Data(7);
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CRC16_Calc: process( Clock, Reset )
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CRC16_Calc: process( Clock, Reset )
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begin
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begin
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if( Reset = Reset_Level )then
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if( Reset = Reset_Level )then
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Reg_Sel <= "00";
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Reg_Sel_q <= "00";
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Wr_En <= '0';
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Wr_En_q <= '0';
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Wr_Data_q <= x"00";
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Wr_Data_q <= x"00";
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Rd_En <= '0';
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Rd_En_q <= '0';
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Rd_Data <= OPEN8_NULLBUS;
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Rd_Data <= OPEN8_NULLBUS;
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Byte_Count <= x"00";
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Byte_Count <= x"00";
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Calc_En <= '0';
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Calc_En <= '0';
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Buffer_En <= '0';
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Buffer_En <= '0';
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Data <= x"00";
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Data <= x"00";
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Reg <= x"0000";
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Reg <= x"0000";
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elsif( rising_edge(Clock) )then
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elsif( rising_edge(Clock) )then
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Reg_Sel <= Reg_Addr;
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Reg_Sel_q <= Reg_Sel_d;
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Wr_En <= Addr_Match and Open8_Bus.Wr_En;
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Wr_En_q <= Wr_En_d;
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Wr_Data_q <= Open8_Bus.Wr_Data;
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Wr_Data_q <= Wr_Data_d;
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if( Wr_En = '1' )then
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if( Wr_En_q = '1' )then
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case( Reg_Sel )is
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case( Reg_Sel_q )is
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when "00" => -- Load next byte
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when "00" => -- Load next byte
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Data <= Wr_Data_q;
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Data <= Wr_Data_q;
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Calc_En <= '1';
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Calc_En <= '1';
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when "01" => -- Clear accumulator and byte counter
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when "01" => -- Clear accumulator and byte counter
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| Line 136... |
Line 143... |
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when others => null;
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when others => null;
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end case;
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end case;
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end if;
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end if;
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Rd_En <= Addr_Match and Open8_Bus.Rd_En;
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Rd_En_q <= Rd_En_d;
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Rd_Data <= OPEN8_NULLBUS;
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Rd_Data <= OPEN8_NULLBUS;
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if( Rd_En = '1' )then
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if( Rd_En_q = '1' )then
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case( Reg_Sel )is
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case( Reg_Sel_q )is
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when "00" => -- Read last byte
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when "00" => -- Read last byte
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Rd_Data <= Data;
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Rd_Data <= Data;
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when "01" => -- Read the byte counter
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when "01" => -- Read the byte counter
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Rd_Data <= Byte_Count;
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Rd_Data <= Byte_Count;
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