Freescale Semiconductor, Inc.
Keyboard/External Interrupt Module (KBI)
Functional Description
ACKI
RESET
TO CPU FOR
BIL/BIH
INSTRUCTIONS
VECTOR
FETCH
DECODER
V
DD
V
INTERNAL
PULLUP
DEVICE
DD
IRQ1F
CLR
IRQ1
D
Q
SYNCHRO-
NIZER
INTERRUPT
REQUEST
CK
IRQ1
IRQ1
LATCH
IRQ1/KEYBOARD
INTERRUPT
REQUEST
IMASKI
KEYBOARD
INTERRUPT
REQUEST
MODEI
HIGH
VOLTAGE
DETECT
TO MODE
SELECT
LOGIC
Figure 14-1. IRQ Block Diagram
Addr.
Register Name
Bit 7
6
0
5
4
3
KEYF
R
2
1
Bit 0
Read: IRQ1F
0
ACKK
0
IRQ and Keyboard Status
and Control Register
(INTKBSCR)
IMASKI MODEI
IMASKK MODEK
$001A
Write:
Reset:
Read:
R
0
ACKI
0
See page 193.
0
KBIE5
0
0
0
0
KBIE1
0
0
0
0
Keyboard Interrupt Enable
KBIE6
0
KBIE4
KBIE3
0
KBIE2
0
$001B
Register (INTKBIER) Write:
See page 195.
Reset:
0
0
0
= Unimplemented
R
= Reserved
Figure 14-2. IRQ and Keyboard I/O Register Summary
MC68HC908RFRK2
MOTOROLA
AdvanceInformation
185
Keyboard/External Interrupt Module (KBI)
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