2 use ieee.std_logic_1164.all;
3 use ieee.numeric_std.all;
6 entity pc_communication is
8 sys_clk : in std_logic;
9 sys_res_n : in std_logic;
15 tx_data : out std_logic_vector(7 downto 0);
16 tx_new : out std_logic;
17 tx_done : in std_logic;
20 rx_data : in std_logic_vector(7 downto 0); --not really required
21 rx_new : in std_logic;
25 d_spalte : out hspalte;
26 d_get : out std_logic;
27 d_done : in std_logic;
30 end entity pc_communication;
32 architecture beh of pc_communication is
33 signal push_history, push_history_next : std_logic;
35 signal spalte, spalte_next : hspalte;
36 signal zeile , zeile_next : hzeile;
37 signal spalte_up, spalte_up_next : std_logic;
38 signal get, get_next : std_logic;
40 signal char, char_next : hbyte;
41 signal char_en : std_logic;
42 type STATE_PC is (IDLE, FETCH, FORWARD, DONE);
43 signal state, state_next : STATE_PC ;
52 sync: process (sys_clk, sys_res_n)
54 if sys_res_n = '0' then
58 spalte_next <= "0000000";
60 zeile_next <= "0000000";
63 tx_data <= "00000000";
64 elsif rising_edge(sys_clk) then
65 push_history <= push_history_next;
66 spalte <= spalte_next;
70 if (char_en = '1') then
76 process (spalte_up, spalte, zeile)
77 variable spalte_tmp, zeile_tmp : integer;
78 variable spalte2_tmp, zeile2_tmp : std_logic_vector(7 downto 0);
80 if (spalte_up = '1') then
81 if (spalte > X"45") then
82 spalte_next <= "0000000";
83 zeile_tmp := to_integer(unsigned(zeile)) + 1;
84 zeile2_tmp := std_logic_vector(to_unsigned(zeile_tmp,8));
85 zeile_next <= hzeile(zeile2_tmp(6 downto 0));
87 spalte_tmp := to_integer(unsigned(spalte)) + 1;
88 spalte2_tmp := std_logic_vector(to_unsigned(spalte_tmp,8));
89 spalte_next <= hspalte(spalte2_tmp(6 downto 0));
96 async_push_history : process (rx_new, rx_data, btn_a)
99 if rx_data = X"41" then
100 push_history_next <= '1';
102 push_history_next <= '0';
104 elsif btn_a = '1' then
105 push_history_next <= '1';
107 push_history_next <= '0';
109 end process async_push_history;
111 output_pc : process (state, zeile, spalte, char)
114 spalte_next <= "0000000";
115 zeile_next <= "0000000";
129 end process output_pc;
131 next_state_pc : process (rx_new, btn_a, d_done, tx_done)
136 if rx_new = '1' or btn_a = '1' then
138 char <= d_char; --latch
141 if (d_done = '1') then
142 state_next <= FORWARD;
145 if (tx_done = '1') then
152 end process next_state_pc;
154 end architecture beh;