敏感度列表中的哪个信号触发该过程 [英] Which signal in the sensitivity list triggers the process

问题描述

在 VHDL 中，在模拟测试平台时，我有一个过程和一个敏感度列表.是否可以查看敏感度列表中的哪个信号触发了该过程?我知道这可能取决于工具.我正在使用赛灵思 ISE.模拟器是否提供此信息?

In VHDL, when simulating a testbench, I have a process and a sensitivity list. Is it possible to see which signal in the sensitivity list has triggered the process? I understand that this may be dependent on the tools. Im using Xilinx ISE. Does the simulator give this information?

推荐答案

您可以将 'transaction 属性与 'event 结合使用来确定哪些信号具有当前增量周期中的交易:

You can use the 'transaction attribute in conjunction with 'event to determine which signals have had a transaction in the current delta cycle:

process(a, b) is
begin
  if a'transaction'event then
    report "Transaction on a";
  end if;

  if b'transaction'event then
    report "Transaction on b";
  end if;
end process;

'transaction 属性创建一个新的 bit 类型信号，该信号在每个事务上切换.该信号上的 'event 属性标识父信号上何时发生任何事务.

The 'transaction attribute creates a new signal of type bit that toggles on each transaction. The 'event attribute on that signal identifies when any transaction has happened on the parent signal.

您还可以使用 not 'quiet(0 ns) 来确定敏感度列表中的哪些信号自上一个时间步以来进行了交易:

You can also use not <signal name>'quiet(0 ns) to determine which signals from a sensitivity list have had a transaction since the last time step:

process(a, b) is
begin
  if not a'quiet(0 ns) then
    report "Transaction on a";
  end if;

  if not b'quiet(0 ns) then
    report "Transaction on b";
  end if;
end process;

如果您不想处理在不同 delta 周期上发生的事件顺序，后者可能更有用.

The latter may be more useful if you don't want to deal with sequencing of events that happen on different delta cycles.

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