alt_cusp72_clock_reset.vhd

nios里面用自定义指令集来实现三角函数

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LIBRARY IEEE, ALTERA;
USE IEEE.std_logic_1164.ALL;
USE altera.ALT_CUSP72_PACKAGE.ALL;

ENTITY alt_cusp72_clock_reset IS
  GENERIC (
        NAME         : STRING := "";
        SIMULATION   : INTEGER := SIMULATION_OFF;
        OPTIMIZED    : INTEGER := OPTIMIZED_ON;
        FAMILY       : INTEGER := FAMILY_STRATIX;
        PERIOD : TIME := 10 ns
  );
  PORT (
      clock      : OUT STD_LOGIC;
      reset      : OUT STD_LOGIC
  );
END ENTITY;


ARCHITECTURE rtl OF alt_cusp72_clock_reset IS
  
BEGIN

clock_and_reset: PROCESS
  BEGIN
    clock <= '0';
    reset <= '0';
    wait for PERIOD/2;
    
    clock <= '0';       -- 1 clock cycle
    wait for PERIOD/2;
    clock <= '1';
    wait for PERIOD/2;

    clock <= '0';       -- reset the dut    
    reset <= '1';
    wait for PERIOD;
    reset <= '0';
    
    while true loop     -- run the clock
	    clock <= '0';
	    wait for PERIOD/2;
	    clock <= '1';
	    wait for PERIOD/2;
    end loop; 
  END PROCESS;

END ARCHITECTURE;