MC68HC08JL3_05 Datasheet, PDF (156/198 Pages) Freescale Semiconductor, Inc – Microcontrollers

Addr. Register Name
$001A
Keyboard Status ^Read:
and Control Register Write:
(KBSCR) _Reset:
Read:
$001B
Keyboard Interrupt Enable
Register (KBIER)
Write:
Reset:
Bit 7
0
0
0
0
6
0
0
KBIE6
0
5
0
0
KBIE5
0
4
0
0
KBIE4
0
3
KEYF
0
KBIE3
0
= Unimplemented
Figure 14-1. KBI I/O Register Summary
2
0
ACKK
0
1
Bit 0
IMASKK MODEK
0
0
KBIE2 KBIE1 KBIE0
0
0
0
14.4 Functional Description
INTERNAL BUS
KBI0
.
KBIE0
.
TO PULLUP ENABLE
.
KBI6
KBIE6
TO PULLUP ENABLE
Technical Data
156
V_DD
D ^CLR Q
CK
ACKK
RESET
KEYBOARD
INTERRUPT FF
VECTOR FETCH
DECODER
KEYF
SYNCHRONIZER
Keyboard
Interrupt
Request
IMASKK
MODEK
Figure 14-2. Keyboard Interrupt Block Diagram
Writing to the KBIE6–KBIE0 bits in the keyboard interrupt enable register
independently enables or disables each port A pin as a keyboard
interrupt pin. Enabling a keyboard interrupt pin in port A also enables its
internal pull-up device irrespective of PTAPUEx bits in the port A input
pull-up enable register (see 12.3.3). A logic 0 applied to an enabled
keyboard interrupt pin latches a keyboard interrupt request.
MC68H(R)C08JL3 — Rev. 4.1
Freescale Semiconductor