Datasheet

Keyboard Interrupt Module (KBI)
MC68HC908JL3E Family Data Sheet, Rev. 4
120 Freescale Semiconductor
12.5.1 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 on port-A. Reset clears the KEYF bit.
1 = Keyboard interrupt pending
0 = No keyboard interrupt pending
ACKK — Keyboard Acknowledge Bit
Writing a 1 to this write-only bit clears the keyboard interrupt request on port-A. ACKK always reads
as 0. Reset clears ACKK.
IMASKK— Keyboard Interrupt Mask Bit
Writing a 1 to this read/write bit prevents the output of the keyboard interrupt mask from generating
interrupt requests on port-A. 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 on port-A. Reset
clears MODEK.
1 = Keyboard interrupt requests on falling edges and low levels
0 = Keyboard interrupt requests on falling edges only
Address: $001A
Bit 7654321Bit 0
Read:0000KEYF0
IMASKK MODEK
Write: ACKK
Reset:00000000
= Unimplemented
Figure 12-3. Keyboard Status and Control Register (KBSCR)