MC68HC908GZ8 Datasheet, PDF (143/344 Pages) Motorola, Inc – Microcontrollers

Keyboard Interrupt Module (KBI)
I/O Registers
13.7.1 Keyboard Status and Control Register
The keyboard status and control register:
• Flags keyboard interrupt requests
• Acknowledges keyboard interrupt requests
• Masks keyboard interrupt requests
• Controls keyboard interrupt triggering sensitivity
Address: $001A
Bit 7
Read:
0
Write:
Reset:
0
6
5
0
0
0
0
= Unimplemented
4
3
2
1
Bit 0
0
KEYF
0
ACKK
IMASKK MODEK
0
0
0
0
0
Figure 13-3. Keyboard Status and Control Register (INTKBSCR)
Bits 7–4 — Not used
These read-only bits always read as logic 0s.
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
MC68HC908GZ8
Freescale Semiconductor
Keyboard Interrupt Module (KBI)
Data Sheet
143