Subversion Repositories iota_pow_vhdl

-- IOTA Pearl Diver VHDL Port

--

-- Written 2018 by Thomas Pototschnig <microengineer18@gmail.com>

--

-- This source code is currently licensed under

-- Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

-- 

-- http://www.microengineer.eu

-- 

-- If you like my project please consider a donation to

--

-- LLEYMHRKXWSPMGCMZFPKKTHSEMYJTNAZXSAYZGQUEXLXEEWPXUNWBFDWESOJVLHQHXOPQEYXGIRBYTLRWHMJAOSHUY

--

-- As soon as donations reach 1000MIOTA, everything will become

-- GPL and open for any use - commercial included.

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use work.index_table.all;

entity curl is

        generic

        (

                HASH_LENGTH : integer := 243;

                STATE_LENGTH : integer := 729; -- 3 * HASH_LENGTH;

                NONCE_LENGTH : integer := 81; -- HASH_LENGTH / 3;

                NUMBER_OF_ROUNDS : integer := 81;

                PARALLEL : integer := 7;

                INTERN_NONCE_LENGTH : integer   := 32;

                BITS_MIN_WEIGHT_MAGINUTE_MAX : integer := 26;

                DATA_WIDTH : integer := 9;

                NONCE_OFFSET : integer := 162   -- we hope it nevery changes

        );

        port

        (

                clk : in std_logic;

                clk_slow : in std_logic;

                reset : in std_logic;

                spi_data_rx : in std_logic_vector(31 downto 0);

                spi_data_tx : out std_logic_vector(31 downto 0);

                spi_data_rxen : in std_logic;

                overflow : out std_logic;

                running : out std_logic;

                found : out std_logic

        );

end curl;

architecture behv of curl is

subtype state_vector_type is std_logic_vector(PARALLEL-1 downto 0);

subtype mid_state_vector_type is std_logic_vector(DATA_WIDTH-1 downto 0);

subtype min_weight_magnitude_type is std_logic_vector(BITS_MIN_WEIGHT_MAGINUTE_MAX-1 downto 0);

type curl_state_array is array(integer range <>) of state_vector_type;

type mid_state_array is array(integer range <>) of mid_state_vector_type;

type min_weight_magnitude_array is array(integer range<>) of min_weight_magnitude_type;

signal curl_state_low : curl_state_array(STATE_LENGTH-1 downto 0);

signal curl_state_high : curl_state_array(STATE_LENGTH-1 downto 0);

-- mid state data in 9bit packed format

signal curl_mid_state_low : mid_state_array((STATE_LENGTH/9)-1 downto 0);

signal curl_mid_state_high : mid_state_array((STATE_LENGTH/9)-1 downto 0);

signal flag_running : std_logic := '0';

signal flag_overflow : std_logic := '0';

signal flag_found : std_logic := '0';

signal flag_start : std_logic := '0';

signal binary_nonce : unsigned(INTERN_NONCE_LENGTH-1 downto 0);

signal mask : state_vector_type;

signal min_weight_magnitude : min_weight_magnitude_type;

function expand(b : std_logic)

        return state_vector_type is

begin

        if b = '1' then

                return (others => '1');

        else

                return (others => '0');

        end if;

end expand;

begin

        overflow <= flag_overflow;

        running <= flag_running;

        found <= flag_found;

        process (clk_slow)

        -- because it looks prettier

                variable spi_cmd : std_logic_vector(5 downto 0);

                variable addrptr : unsigned(7 downto 0) := x"00";

        begin

                if rising_edge(clk_slow) then

                        if reset='1' then

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

                                flag_start <= '0';

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

--                              curl_mid_state_low <= (others => (others => '0'));

--                              curl_mid_state_high <= (others => (others => '0'));

                                addrptr := x"00";

                        else

                                flag_start <= '0';

-- new spi data received

                                if spi_data_rxen = '1' then

                                        spi_cmd := spi_data_rx(31 downto 26);

                                        case spi_cmd is

                                                when "000000" => -- nop (mainly for reading back data)

                                                when "100001" => -- start / stop

                                                        flag_start <= spi_data_rx(0);

                                                when "100101" =>        -- write to wr address

                                                        addrptr := unsigned(spi_data_rx(7 downto 0));

                                                when "100010" =>        -- write to mid state

                                                        if (addrptr <= (STATE_LENGTH/9)-1) then

                                                                curl_mid_state_low(to_integer(addrptr)) <= spi_data_rx(DATA_WIDTH-1 downto 0);

                                                                curl_mid_state_high(to_integer(addrptr)) <= spi_data_rx(DATA_WIDTH+8 downto DATA_WIDTH);

                                                        end if;

                                                        spi_data_tx <= spi_data_rx;

                                                        addrptr := addrptr + 1;

                                                when "100100" =>

                                                        min_weight_magnitude <= spi_data_rx(BITS_MIN_WEIGHT_MAGINUTE_MAX-1 downto 0);

                                                when "000001" =>        -- read flags

                                                        spi_data_tx(2 downto 0) <= flag_overflow & flag_found & flag_running;

-- for debugging onle ... read back curl_state

--                                              when "000010" =>

--                                                      spi_addr := spi_data_rx(25 downto 16);

--                                                      spi_data_tx(0+PARALLEL-1 downto 0) <= curl_state_low(to_integer(unsigned(spi_addr)));

--                                                      spi_data_tx(8+PARALLEL-1 downto 8) <= curl_state_high(to_integer(unsigned(spi_addr)));

-- for debugging only ... read back mid_state

--                                              when "000111" =>

--                                                      if (addrptr <= (STATE_LENGTH/9)-1) then

--                                                              spi_data_tx(DATA_WIDTH-1 downto 0) <= curl_mid_state_low(to_integer(addrptr));

--                                                              spi_data_tx(DATA_WIDTH+8 downto DATA_WIDTH) <= curl_mid_state_high(to_integer(addrptr));

--                                                      else

--                                                              spi_data_tx <= (others => '0');

--                                                      end if;

--                                                      addrptr := addrptr + 1; -- dual-used for debugging purposes 

                                                when "000011" => -- read nonce

                                                        spi_data_tx(INTERN_NONCE_LENGTH-1 downto 0) <= std_logic_vector(binary_nonce);

                                                when "000100" => -- read mask

                                                        spi_data_tx(PARALLEL-1 downto 0) <= mask;

                                                when "010101" => -- loop back read test inverted bits

                                                        spi_data_tx <= not spi_data_rx;

                                                when "000110" => -- read back parallel-level

                                                        spi_data_tx(3 downto 0) <= std_logic_vector(to_unsigned(PARALLEL, 4));

                                                when others =>

                                                        spi_data_tx <= (others => '1');

                                        end case;

                                end if;

                        end if;

                end if;

        end process;

        process (clk)

                variable        state : integer range 0 to 31 := 0;

                variable round : integer range 0 to 127 := 0;

                variable imask : state_vector_type;

                variable i_min_weight_magnitude : min_weight_magnitude_type;

                variable tmp_weight_magnitude : min_weight_magnitude_array(0 to PARALLEL-1);

                variable i_binary_nonce : unsigned(INTERN_NONCE_LENGTH-1 downto 0);

                -- temporary registers get optimized away

                variable alpha : curl_state_array(STATE_LENGTH-1 downto 0);

                variable beta : curl_state_array(STATE_LENGTH-1 downto 0);

                variable gamma : curl_state_array(STATE_LENGTH-1 downto 0);

                variable delta : curl_state_array(STATE_LENGTH-1 downto 0);

                variable tmp_index : integer range 0 to 1023;

                variable tmp_highest_bit : integer range 0 to 31;

        begin

                if rising_edge(clk) then

                        if reset='1' then

                                state := 0;

                                round := 0;

                                flag_found <= '0';

                                flag_running <= '0';

                                flag_overflow <= '0';

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

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

--                              curl_state_low <= (others => (others => '0'));

--                              curl_state_high <= (others => (others => '0'));

--                              tmp_weight_magnitude := (others => (others => '0'));

                                i_binary_nonce := (others => '0');

                                imask := (others => '0');

                                i_min_weight_magnitude := (others => '0');

                                alpha := (others => (others => '0'));

                                beta := (others => (others => '0'));

                                gamma := (others => (others => '0'));

                                delta := (others => (others => '0'));

                                tmp_index := 0;

                        else

                                case state is

                                        when 0 =>

                                                mask <= imask;

                                                binary_nonce <= i_binary_nonce;

                                                flag_running <= '0';

                                                if flag_start = '1' then

                                                        i_binary_nonce := x"00000000";

                                                        i_min_weight_magnitude := min_weight_magnitude;

                                                        state := 1;

                                                end if;

                                                -- nop until start from spi

                                        when 1 =>

                                                flag_found <= '0';

                                                flag_running <= '1';

                                                flag_overflow <= '0';

                                                state := 8;

                                        when 8 =>       -- copy mid state and insert nonce

                                                -- copy and fully expand mid-state to curl-state

                                                for I in 0 to (STATE_LENGTH/DATA_WIDTH)-1 loop

                                                        for J in 0 to DATA_WIDTH-1 loop

                                                                tmp_index := I*DATA_WIDTH+J;

                                                                if  tmp_index < NONCE_OFFSET or tmp_index > NONCE_OFFSET + NONCE_LENGTH - 1 then

                                                                        curl_state_low(tmp_index) <= expand(curl_mid_state_low(I)(J));

                                                                        curl_state_high(tmp_index) <= expand(curl_mid_state_high(I)(J));

                                                                end if;

                                                        end loop;

                                                end loop;

                                                -- fill all ... synthesizer is smart enough to optimize away what is not needed

                                                for I in NONCE_OFFSET to NONCE_OFFSET + NONCE_LENGTH - 1 loop

                                                        curl_state_low(I) <= expand('1');

                                                        curl_state_high(I) <= expand('1');

                                                end loop;

                                                -- calculate log2(x) by determining the place of highest set bit

                                                -- this is calculated on constants, so no logic needed

                                                tmp_highest_bit := 0;

                                                for I in 0 to 31 loop    -- 32 is enough ...^^

                                                        if to_unsigned(PARALLEL-1, 32)(I) = '1' then

                                                                tmp_highest_bit := I;

                                                        end if;

                                                end loop;

--                                              -- generate bitmuster in first trit-arrays of nonce depending on PARALLEL setting

                                                -- this is calculated on constants, so no logic needed

                                                for I in 0 to PARALLEL-1 loop

                                                        for J in 0 to tmp_highest_bit loop

                                                                curl_state_low(NONCE_OFFSET+J)(I) <= to_unsigned(I, tmp_highest_bit+1)(J);

                                                                curl_state_high(NONCE_OFFSET+J)(I) <= not to_unsigned(I, tmp_highest_bit+1)(J);

                                                        end loop;

                                                end loop;

                                                -- insert and convert binary nonce to ternary nonce

                                                -- It's a fake ternary nonce but integer-values are strictly monotonously rising 

                                                -- with integer values of binary nonce.

                                                -- Doesn't bring the exact same result like reference implementation with real

                                                -- ternary adder - but it doesn't matter and it is way faster.

                                                -- conveniently put nonce counter at the end of nonce

                                                for I in 0 to INTERN_NONCE_LENGTH-1 loop

                                                        curl_state_low(NONCE_OFFSET + NONCE_LENGTH - INTERN_NONCE_LENGTH + I) <= expand(i_binary_nonce(I));

                                                        curl_state_high(NONCE_OFFSET + NONCE_LENGTH - INTERN_NONCE_LENGTH + I) <= not expand(i_binary_nonce(I));

                                                end loop;

                                                -- initialize round-counter

                                                round := NUMBER_OF_ROUNDS;

                                                state := 10;

                                        when 10 =>      -- do the curl hash round without any copying needed

                                                if round = 1 then

                                                        state := 16;

                                                end if;

                                                for I in 0 to STATE_LENGTH-1 loop

                                                        alpha(I) := curl_state_low(index_table(I));

                                                        beta(I) := curl_state_high(index_table(I));

                                                        gamma(I) := curl_state_high(index_table(I+1));

                                                        delta(I) := (alpha(I) or (not gamma(I))) and (curl_state_low(index_table(I+1)) xor beta(I));

                                                        curl_state_low(I) <= not delta(I);

                                                        curl_state_high(I) <= (alpha(I) xor gamma(I)) or delta(I);

                                                end loop;

                                                round := round - 1;

                                        when 16 =>  -- find out which solution - if any

                                                imask := (others => '0');

                                                -- transform "vertical" trits to "horizontal" bits

                                                -- and compare with min weight magnitude mask

                                                for I in 0 to PARALLEL-1 loop

                                                        tmp_weight_magnitude(I) := (others => '0');

                                                        for J in 0 to BITS_MIN_WEIGHT_MAGINUTE_MAX-1 loop

                                                                tmp_weight_magnitude(I)(J) := curl_state_low(HASH_LENGTH - 1 - J)(I) and curl_state_high(HASH_LENGTH - 1 - J)(I);

                                                        end loop;

                                                        tmp_weight_magnitude(I) := tmp_weight_magnitude(I) and i_min_weight_magnitude; -- only consider used bits

                                                        if tmp_weight_magnitude(I) = i_min_weight_magnitude then

                                                                imask(I) := '1';

                                                        end if;

                                                end loop;

                                                state := 17;

                                        when 17 =>

                                                if unsigned(imask) /= 0 then

                                                        state := 30;

                                                elsif i_binary_nonce = x"ffffffff" then

                                                        state := 31;

                                                else

                                                        i_binary_nonce := i_binary_nonce + 1;

                                                        state := 8;

                                                end if;

                                        when 30 =>

                                                flag_found <= '1';

                                                state := 0;

                                        when 31 =>

                                                flag_overflow <= '1';

                                                state := 0;

                                        when others =>

                                                state := 0;

                                end case;

                        end if;

                end if;

        end process;

end behv;