在spru773a中有关中断的描述中，The reset interrupt service fetch packet must be located at address 0 ，但在address 0的位置不应该是二级boot代码吗？在address 0到底是二级boot代码还是其他的东西
Interrupt service table base portion of the IST address. This field is cleared to 0 on reset; therefore, upon startup the IST must reside at address 0. After reset, you can relocate the IST by writing a new value to ISTB. If relocated, the first ISFP(corresponding to RESET) is never executed via interrupt processing, because reset clears the ISTB to 0.
