可表示硬件的函数或任务应该是可重入的还是不可重入的？

老阮

•If a task or function is to be re-entrant, it should be automatic.The variables also ought to be automatic, unless there is a specific reason for keeping the value from one call to the next. As a simple example, a variable that keeps a count of the number of times an automatic task or function is called would need to be static.
• If a task or function represents the behavior of a single piece of hardware, and therefore is not re-entrant, then it should be declared as static, and all variables within the task or function should be static.


重点请看加粗部分，请问如何理解表示硬件的函数或任务是不可重入的？


我的理解是，如果调用多次函数来生成多个相同的硬件，那里面的变量应该是automatic的，所以应该是可重入的才对？


而且在阅读本书的时候，后文中也说明了函数和任务如果要是可综合的，必须是automatic的。


上述英文部分是否有误？