MC68HC908JL3E Datasheet, PDF (172/226 Pages) Motorola, Inc – Microcontrollers

Keyboard Interrupt Module (KBI)
Addr.
$001A
$001B
Register Name
Bit 7
6
5
4
3
Read: 0
0
0
0
KEYF
Keyboard Status
and Control Register Write:
(KBSCR)
Reset: 0
0
0
0
0
Read: 0
Keyboard Interrupt
Enable Register Write:
(KBIER)
Reset: 0
KBIE6 KBIE5 KBIE4 KBIE3
0
0
0
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
172
V_DD
CLR
D
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 Port A Input Pull-up Enable
Register (PTAPUE)). A logic 0 applied to an enabled keyboard interrupt
pin latches a keyboard interrupt request.
MC68H(R)C908JL3E/JK3E/JK1E — Rev. 2.0
Keyboard Interrupt Module (KBI)
MOTOROLA