User`s manual

APPENDIX 
60
MB770 User’s Manual
B. Interrupt Request Lines (IRQ) 
Peripheral devices use interrupt request lines to notify CPU for the 
service required. The following table shows the IRQ used by the devices 
on board. 
Level  Function 
IRQ0  System Timer Output 
IRQ1 Keyboard 
IRQ2 Interrupt Cascade 
IRQ3  Serial Port #2 
IRQ4  Serial Port #1 
IRQ5 Reserved 
IRQ6  Floppy Disk Controller 
IRQ7  Parallel Port #1 
IRQ8  Real Time Clock 
IRQ9 Reserved 
IRQ10 Reserved 
IRQ11 Reserved 
IRQ12 PS/2 Mouse 
IRQ13 80287 
IRQ14 Primary IDE 
IRQ15 Secondary IDE 










