Code:
with note(8 downto 6) select
pitch <= "1101110111110010001" when "001", -- 110 Hz
"0110111011111001000" when "010", -- 220 Hz
"0011011101111100100" when "011", -- 440 Hz
"0001101110111110010" when "100", -- 880 Hz
"0000110111011111001" when "101", -- 1760 Hz
"0000011011101111100" when "110", -- 3520 Hz
"0000001101110111110" when "111", -- 7040 Hz
"0000000000000000000" when others;
with note(5 downto 3) select
duration <= "00000010111110101111000010" when "001", -- 1/64
"00000101111101011110000100" when "010", -- 1/32
"00001011111010111100001000" when "011", -- 1/16
"00010111110101111000010000" when "100", -- 1/8
"00101111101011110000100000" when "101", -- 1/4
"01011111010111100001000000" when "110", -- 1/2
"10111110101111000010000000" when "111", -- 1/1
"00000000000000000000000000" when others;
Vì sao họ chú thích là
--110Hz
--240Hz
--480Hz
--1/64
--1/32

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