VHDL是否具有三元运算符？ [英] Does VHDL have a ternary operator?

问题描述

我喜欢三元运算符和if子句的简洁性。

I love the neatness of the ternary operator vs if clauses.

该运算符是否存在于vhdl中？我的搜索恰恰相反。我还检查了when语句，但它不是运算符，我也希望能够在流程中使用它。

Does this operator exist in vhdl? My search was to the contrary. I also checked the when statement out, but it's not an operator, and I want to be able to use it in processes, too...

推荐答案

否在VHDL-2008上进行了讨论，但没有参与。您有几种选择。如果您的工具支持VHDL-2008，则条件支持现在可以作为顺序语句（它们以前只是并发的）而受支持，因此您可以编写以下内容：

No. It was discussed for VHDL-2008, but didn't get in. You've got a couple of options. If your tools support VHDL-2008, conditional assignments are now supported as sequential statements (they were previously just concurrent), so you can write something like:

process(clock)
begin
  if rising_edge(clock) then
    q <= '0' when reset else d; -- ie. much like q <= reset? '0':d;
  end if;
end process;

如果您还没有2008年，只需编写一个函数（ q < ; = sel（reset，'0'，d））。不过，您必须针对每种感兴趣的类型编写它。

If you haven't got 2008, just write a function (q <= sel(reset, '0', d)). You have to write it for every type you're interested in, though.

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