Question

我有两个2D数组：

type array1x1D is array (0 to 10) of std_logic_vector(0 to 10); -- Array of arrays
type array2D is array (0 to 10, 0 to 10) of std_logic; -- Real 2D array

如何访问前者的std_logic_vectors范围和后者的范围？我当然可以使用变量来跟踪它们的大小，但我宁愿避免这种情况。我试图使用GENERATE语句循环遍历数组。

Answer 1

<强> array1x1D：

VHDL-2002：如果您是std_logic_vector(0 downto 10)，则需要子类型想得到这部分的范围，从而将类型分为：

subtype array1x1D_element is std_logic_vector(0 to 10);
type array1x1D is array (0 to 10) of array1x1D_element; -- Array of arrays

然后你可以array1x1D_element'range。

VHDL-2008：使用添加的'element属性（可能用于此目的:-)，并写下array1x1D'element'range。

<强> array2D：

通过指向'range的索引访问不同的维度使用array2D'range(1)和array2D'range(2)。

Answer 2

entity test1 is
end entity;
library ieee;
use ieee.std_logic_1164.all;
architecture a1 of test1 is
    type array1x1D is array (0 to 10) of std_logic_vector(0 to 10); -- Array of arrays
    type array2D is array (0 to 10, 0 to 5) of std_logic; -- Real 2D array
    signal s1 : array1x1D;
begin
    name : process is
    begin
        report "array1x1D(0)'length:" & integer'image(s1(0)'length);
        report "array2D'length(1):" & integer'image(array2D'length(1));
        report "array2D'length(2):" & integer'image(array2D'length(2));
        wait;
    end process name;
end architecture a1;

产生

# run -all
# ** Note: array1x1D(0)'length:11
#    Time: 0 ns  Iteration: 0  Instance: /test1
# ** Note: array2D'length(1):11
#    Time: 0 ns  Iteration: 0  Instance: /test1
# ** Note: array2D'length(2):6
#    Time: 0 ns  Iteration: 0  Instance: /test1
#

我无法立即找到一种方法来计算1d数组的矢量元素的长度，而没有该类型的中间信号/常数/变量......

VHDL - 确定2d阵列的范围

2 个答案: