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Keyboard Interrupt Module (KBI)
Technical Data
MC68H(R)C908JL3E/JK3E/JK1E
—
Rev. 2.0
176
Keyboard Interrupt Module (KBI)
MOTOROLA
ACKK — Keyboard Acknowledge Bit
Writing a logic 1 to this write-only bit clears the keyboard interrupt
request on port-A. 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 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
14.4.3 Keyboard Interrupt Enable Register
The port-A keyboard interrupt enable register enables or disables each
port-A pin to operate as a keyboard interrupt pin.
KBIE6–KBIE0 — Port-A Keyboard Interrupt Enable Bits
Each of these read/write bits enables the corresponding keyboard
interrupt pin on port-A 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:
$001B
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
KBIE6
KBIE5
KBIE4
KBIE3
KBIE2
KBIE1
KBIE0
Write:
Reset:
0
0
0
0
0
0
0
0
Figure 14-4. Keyboard Interrupt Enable Register (KBIER)