Datasheet

Keyboard Interrupt Module (KBI)
MC68HC908AP Family Data Sheet, Rev. 4
280 Freescale Semiconductor
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
18.5.2 Keyboard Interrupt Enable Register
The port-D keyboard interrupt enable register enables or disables each port-D pin to operate as a
keyboard interrupt pin.
KBIE7–KBIE0 — Keyboard Interrupt Enable Bits
Each of these read/write bits enables the corresponding keyboard interrupt pin to latch interrupt
requests. Reset clears the keyboard interrupt enable register.
1 = KBIx pin enabled as keyboard interrupt pin
0 = KBIx pin not enabled as keyboard interrupt pin
Address: $001A
Bit 7654321Bit 0
Read: 0000KEYF 0
IMASKK MODEK
Write: ACKK
Reset:00000000
= Unimplemented
Figure 18-3. Keyboard Status and Control Register (KBSCR)
Address: $001B
Bit 7654321Bit 0
Read:
KBIE7 KBIE6 KBIE5 KBIE4 KBIE3 KBIE2 KBIE1 KBIE0
Write:
Reset:00000000
Figure 18-4. Keyboard Interrupt Enable Register (KBIER)