Fpga双ram乒乓操作vhdl

FPGA双RAM乒乓操作通常用于实现双缓冲技术，以提高存储器的读写效率。下面是一个VHDL实现示例：

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

entity dual_ram_ping_pong is
    port (
        clk: in std_logic;
        rst: in std_logic;
        we: in std_logic;
        addr: in unsigned(7 downto 0);
        din: in std_logic_vector(7 downto 0);
        dout: out std_logic_vector(7 downto 0)
    );
end dual_ram_ping_pong;

architecture arch_dual_ram_ping_pong of dual_ram_ping_pong is
    type ram_type is array (0 to 255) of std_logic_vector(7 downto 0);
    signal ram1, ram2: ram_type;
    signal read_addr, write_addr: unsigned(7 downto 0);
begin
    process (clk)
    begin
        if rising_edge(clk) then
            if rst = '1' then
                read_addr <= (others => '0');
                write_addr <= (others => '0');
            elsif we = '1' then
                ram1(to_integer(addr)) <= din;
                write_addr <= addr;
            else
                dout <= ram2(to_integer(read_addr));
                read_addr <= read_addr + 1;
                if read_addr = write_addr then
                    ram2(to_integer(addr)) <= din;
                end if;
            end if;
        end if;
    end process;
end arch_dual_ram_ping_pong;

上述代码中，我们定义了两个256字节大小的RAM存储器，分别为ram1和ram2。读操作时，从ram2中读取数据，同时将write_addr和read_addr递增。写操作时，将数据写入到ram1中，同时更新write_addr。当读写指针相同时，将数据同时写入ram2中，实现了双缓冲。