
Auto Wakeup Module (AWU)
MC68HC908QL4 MC68HC908QL3 MC68HC908QL2 Data Sheet, Rev. 4
60
Freescale Semiconductor
4.6.2 Keyboard Status and Control Register
The keyboard status and control register (KBSCR):
Flags keyboard/auto wakeup interrupt requests
Acknowledges keyboard/auto wakeup interrupt requests
Masks keyboard/auto wakeup interrupt requests
Bits 7–4 — Not used
These read-only bits always read as 0s.
KEYF — Keyboard Flag Bit
This read-only bit is set when a keyboard interrupt is pending on port A or auto wakeup. Reset clears
the KEYF bit.
1 = Keyboard/auto wakeup interrupt pending
0 = No keyboard/auto wakeup interrupt pending
ACKK — Keyboard Acknowledge Bit
Writing a 1 to this write-only bit clears the keyboard/auto wakeup interrupt request on port A and auto
wakeup logic. 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 or auto wakeup. Reset clears the IMASKK bit.
1 = Keyboard/auto wakeup interrupt requests masked
0 = Keyboard/auto wakeup interrupt requests not masked
NOTE
MODEK is not used in conjuction with the auto wakeup feature. For a
description of this bit, see
9.8.1 Keyboard Status and Control Register
(KBSCR)
.
4.6.3 Keyboard Interrupt Enable Register
The keyboard interrupt enable register (KBIER) enables or disables the auto wakeup to operate as a
keyboard/auto wakeup interrupt input.
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
0
0
KEYF
0
IMASKK
MODEK
Write:
ACKK
Reset:
0
0
0
0
0
0
0
0
=Unimplemented
Figure 4-3. Keyboard Status and Control Register (KBSCR)
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
AWUIE
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
Write:
Reset:
0
0
0
0
0
0
0
0
=Unimplemented
Figure 4-4. Keyboard Interrupt Enable Register (KBIER)