网络I/O =崩溃时中断?

It seems that when an I/O pin interrupt occurs while network I/O is being performed, the system resets -- even if the interrupt function only declares a local variable and assigns it (essentially a do-nothing routine.) So I'm fairly certain it isn't to do with spending too much time in the interrupt function. (My actual working interrupt functions are pretty spartan, strictly increment and assign, not even any conditional logic.)It seems that when an I/O pin interrupt occurs