如何比较整数和 std_logic 向量

Question

我有一系列信号。当作为“选择器”的信号等于单元格编号时，我想写入数组中的适当单元格。为了节省编写和代码行，我在生成循环中生成分配：

read_data_signals_gen: for i in 0 to (CAU_num -1) generate

    v_direction_sig(i)(0) <=  DATA_IN when (chosen_flow_sig = i) and (read_state = st_read_v_direction_0) else
                              v_direction_sig(i)(0);
    v_direction_sig(i)(1) <=  DATA_IN when (chosen_flow_sig = i) and (read_state = st_read_v_direction_1) else
                              v_direction_sig(i)(1);
    v_direction_sig(i)(2) <=  DATA_IN when (chosen_flow_sig = i) and (read_state = st_read_v_direction_2) else
                              v_direction_sig(i)
  ...
end generation read_data_signals_gen;

selected_flow_sig 是一个std_logic_vector (1 downto 0)和 gets "00"，"01"，"10"或"11"表示单元格的编号，并且CAU_num是一个integer等于 4的常数。如何在when语句中创建比较，以便整数将等于其二进制转换？

还有一个相关的问题。有没有办法执行以下代码：

type  BitArray is array (natural range <>) of std_logic;

sel_sig : std_logic_vector(0 to 1);
bit_arr : BitArray(0 to 3)

sel_sig <= "00"
bit_arr(sel_sig) <= '1'  -- HOW TO PERFORM THIS? 

Answer 1

您可能正在寻找

to_integer(unsigned(sel_sig))

例如

bit_arr(to_integer(unsigned(sel_sig))) <= '1'

或者

if to_integer(unsigned(sel_sig))=12 then ...