Datasheet

Keyboard Interrupt Module (KBI)
Technical Data MC68HC908LJ12 — Rev. 2.1
368 Keyboard Interrupt Module (KBI) Freescale Semiconductor
19.6.1 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.
IMASKK — Keyboard Interrupt Mask Bit
Writing a logic 1 to this read/write bit prevents the output of the
keyboard interrupt mask from generating interrupt requests. Reset
clears the IMASKK bit.
1 = Keyboard interrupt requests masked
0 = Keyboard interrupt requests not masked
MODEK — Keyboard Triggering Sensitivity Bit
This read/write bit controls the triggering sensitivity of the keyboard
interrupt pins. Reset clears MODEK.
1 = Keyboard interrupt requests on falling edges and low levels
0 = Keyboard interrupt requests on falling edges only
Address: $001B
Bit 7654321Bit 0
Read: 0000KEYF 0
IMASKK MODEK
Write:
ACKK
Reset:00000000
= Unimplemented
Figure 19-3. Keyboard Status and Control Register (KBSCR)