Datasheet

Keyboard Interrupt Module (KBI)
Data Sheet MC68HC908LJ24/LK24 — Rev. 2.1
412 Keyboard Interrupt Module (KBI) Freescale Semiconductor
20.6 Keyboard Interrupt Registers
Two registers control the operation of the keyboard interrupt module:
• Keyboard status and control register (KBSCR)
• Keyboard interrupt enable register (KBIER)
20.6.1 Keyboard Status and Control Register
• Flags keyboard interrupt requests
• Acknowledges keyboard interrupt requests
• Masks keyboard interrupt requests
• Controls keyboard interrupt triggering sensitivity
KEYF — Keyboard Flag Bit
This read-only bit is set when a keyboard interrupt is pending.
Reset clears the KEYF bit.
1 = Keyboard interrupt pending
0 = No keyboard interrupt pending
ACKK — Keyboard Acknowledge Bit
Writing a logic 1 to this write-only bit clears the keyboard interrupt
request. ACKK always reads as logic 0. Reset clears ACKK.
Address: $001B
Bit 7654321Bit 0
Read: 0000KEYF 0
IMASKK MODEK
Write:
ACKK
Reset:00000000
= Unimplemented
Figure 20-3. Keyboard Status and Control Register (KBSCR)