SPRUHZ7K August 2015 – April 2024 AM5706 , AM5708 , AM5716 , AM5718 , AM5718-HIREL
The keyboard controller has an overrun feature: A dedicated buffer allows the keyboard controller to memorize two successive events. If two successive events occur before a read is performed, the second event is stored and a second interrupt is generated when the first interrupt is cleared, allowing two consecutive key events to be received.
If a third event occurs before the first event is treated, a missed event interrupt (the KBD_IRQSTATUS[3] MISS_EVENT bit) is generated to report the lost event.
The MISS_EVENT interrupt is not routed to the KBD_IRQ signal; software must check the KBD_IRQSTATUS[3] MISS_EVENT bit to detect any missed events.