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 : integer range 0 to 71;
36 signal zeile , zeile_next : integer range 0 to 71;
37 signal spalte_up, spalte_up_next : std_logic;
38 signal get, get_next : std_logic;
39 signal new_i, new_i_next : std_logic;
40 signal tx_done_i, tx_done_i_next : std_logic;
41 signal d_done_i : std_logic;
43 signal char, char_next : hbyte;
44 signal char_en : std_logic;
45 type STATE_PC is (IDLE, FETCH, FORWARD, DONE);
46 signal state, state_next : STATE_PC ;
51 d_zeile <= hzeile(std_logic_vector(to_unsigned(zeile,7)));
52 d_spalte <= hspalte(std_logic_vector(to_unsigned(spalte,7)));
57 tx_done_i_next <= tx_done;
59 sync: process (sys_clk, sys_res_n)
61 if sys_res_n = '0' then
68 tx_data <= "00000000";
71 elsif rising_edge(sys_clk) then
72 push_history <= push_history_next;
73 spalte <= spalte_next;
78 tx_done_i <= tx_done_i_next;
79 spalte_up <= spalte_up_next;
80 if (char_en = '1') then
86 process (spalte_up, spalte, zeile)
88 if (spalte_up = '1') then
91 zeile_next <= zeile + 1;
93 spalte_next <= spalte + 1;
97 spalte_next <= spalte;
102 async_push_history : process (rx_new, rx_data, btn_a)
105 if rx_data = X"41" then
106 push_history_next <= '1';
108 push_history_next <= '0';
110 elsif btn_a = '1' then
111 push_history_next <= '1';
113 push_history_next <= '0';
115 end process async_push_history;
117 output_pc : process (state, zeile, spalte, char, tx_done_i)
121 spalte_up_next <= '0';
132 if (tx_done_i = '1') then
133 spalte_up_next <= '1';
138 end process output_pc;
140 next_state_pc : process (rx_new, btn_a, d_done, tx_done_i)
144 if rx_new = '1' or btn_a = '1' then
149 if (d_done = '1') then
150 state_next <= FORWARD;
153 if (tx_done_i = '1') then
159 end process next_state_pc;
161 end architecture beh;