you can register that signal and assign it as the global signal, by the step flow: assign->logic option->Individual logic options->Global signal. But you'd better input the clock signal through the dedicated input pin. （参考译文：可以寄存这个信号, 并将它指定为全局信号, 步骤如下：指定—>逻辑选项—>个别逻辑选项—>全局信号. 但是, 最好通过专用输入引脚输入时钟信号. ）
you can register that signal and assign it as the global signal, by the step flow: assign->logic option->Individual logic options->Global signal. But you'd better input the clock signal through the dedicated input pin. （参考译文：可以寄存这个信号, 并将它指定为全局信号, 步骤如下：指定—>逻辑选项—>个别逻辑选项—>全局信号. 但是, 最好通过专用输入引脚输入时钟信号. ）
