The 1043 kernel sets the external interrupt IRQ 0 high-level trigger interrupt mode. After registering the interrupt service routine. When the high level comes,if IRQ0 is not pulled down, tens of millions of interrupts will be generated within a few seconds, and the system will kernel panic after a while. Even if I pull down IRQ0 as soon as I enter the interrupt service routine,.there will be interrupts but the problem of not entering the interrupt service routine from time to time.