VHDL 类型转换错误：无法将类型“universal_integer”转换为类型“MemoryArray”

Question

编译我的 vhdl 代码时，在第 28 行出现转换错误。

错误：

Error (10305): VHDL Type Conversion error at registers.vhd(28): cannot convert type " universal_integer" to type "MemoryArray"

这是我正在尝试编译的代码：

library ieee;
use ieee.std_logic_1164.all;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
use IEEE.NUMERIC_STD.ALL;

entity registers is
    port(   load : in std_logic;                                    -- 1-bit input
            WriteAddr : in std_logic_vector(1 downto 0);    -- 2 bit write address
            Memin : in std_logic_vector(5 downto 0);    -- 6 bit input data
            clk : in std_logic;                 -- clock
            Memout : out std_logic_vector(5 downto 0)); -- 6 bit output data
end registers;

architecture arch of registers is
    type MemoryArray is array(0 to 3) of STD_LOGIC_VECTOR(5 downto 0); --array of size 4, each index holds 6 bit values
    signal Memory : MemoryArray := (others => (others => '0'));

begin
    
    process(clk)
    begin
        if rising_edge(clk) then
            if (load = '1') then
                case WriteAddr is
                    
                    when "00" =>
                        MemoryArray(0) <= Memin;
                    when "01" =>
                        MemoryArray(1) <= Memin;
                    when "10" =>
                        MemoryArray(2) <= Memin;
                    when "11" =>
                        MemoryArray(3) <= Memin;
                end case;   
            end if;
        end if;
    end process;
    
    process(WriteAddr)
    begin
                     
        case WriteAddr is
            
            when "00" =>
                Memout <= Memory(0);
                
            when "01" =>
                Memout <= Memory(1);
                
            when "10" => 
                Memout <= Memory(2);
                
            when others =>
                Memout <= Memory(3);
        end case;
        
    end process;
    
end arch;

我本质上是在创建一个 LUT，我可以获取每个索引处的值，并使用给定的 Memin 值更改每个索引处的值。

Answer 1

在第一个过程中，您使用了类型

MemoryArray

，而不是保存内存元素的信号名称

memory

。