2812有三个独立的外部可屏蔽中断XINT1,XINT2,XINT13和一个不可屏蔽中断XNMI，外部扩展可屏蔽中断通过CPLD之后，通过按键产生一外部中断EXINT5。-2812 has three independent external maskable interrupt XINT1, XINT2, XINT13 and a non-maskable interrupt XNMI, external expansion through the CPLD can be screened a