-- This design should display incrementing binary numbers
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-- at LED1-LED8 of the GateMate FPGA Starter Kit.
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library ieee ;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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library gatemate;
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use gatemate.components.all;
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entity blink is
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port (
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clk_i : in std_logic; -- 10 MHz clock
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rst_n_i : in std_logic; -- SW3 button
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led_n_o : out std_logic_vector(7 downto 0) -- LED1..LED8
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);
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end entity blink;
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architecture rtl of blink is
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signal s_pll_clk : std_logic;
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signal s_pll_lock : std_logic;
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signal s_clk_cnt : unsigned(19 downto 0);
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signal s_clk_en : boolean;
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signal s_rst_n : std_logic;
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signal s_cfg_end : std_logic;
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signal s_led : unsigned(led_n_o'range);
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begin
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pll : CC_PLL
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generic map (
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REF_CLK => "10",
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OUT_CLK => "2",
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PERF_MD => "ECONOMY"
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)
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port map (
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CLK_REF => clk_i,
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CLK_FEEDBACK => '0',
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USR_CLK_REF => '0',
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USR_LOCKED_STDY_RST => '0',
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USR_PLL_LOCKED_STDY => open,
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USR_PLL_LOCKED => s_pll_lock,
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CLK270 => open,
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CLK180 => open,
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CLK0 => s_pll_clk,
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CLK90 => open,
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CLK_REF_OUT => open
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);
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cfg_end_inst : CC_CFG_END
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port map (
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CFG_END => s_cfg_end
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);
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s_rst_n <= rst_n_i and s_pll_lock and s_cfg_end;
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process (s_pll_clk, s_rst_n) is
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begin
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if (not s_rst_n) then
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s_clk_cnt <= (others => '0');
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elsif (rising_edge(s_pll_clk)) then
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s_clk_cnt <= s_clk_cnt + 1;
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end if;
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end process;
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s_clk_en <= s_clk_cnt = (s_clk_cnt'range => '1');
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process (s_pll_clk, s_rst_n) is
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begin
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if (not s_rst_n) then
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s_led <= x"01";
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elsif (rising_edge(s_pll_clk)) then
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if (s_clk_en) then
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s_led <= s_led(6 downto 0) & s_led(7);
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end if;
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end if;
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end process;
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led_n_o <= not std_logic_vector(s_led);
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end architecture;
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