Datasheet

MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor 95
Chapter 9
Keyboard Interrupt Module (KBI)
9.1 Introduction
The keyboard interrupt module (KBI) provides five independently maskable external interrupt pins.
9.2 Features
KBI features include:
• Five keyboard interrupt pins, on the MC68HC08KX8, are with separate keyboard interrupt enable
bits and one keyboard interrupt mask
• Hysteresis buffers
• Programmable edge-only or edge- and level-interrupt sensitivity
• Automatic interrupt acknowledge
• Exit from low-power modes
Figure 9-1. Keyboard Module Block Diagram
KB0IE
KB4IE or KB3IE
.
.
.
KEYBOARD
INTERRUPT
DQ
CK
CLR
V
DD
MODEK
IMASKK
KEYBOARD
INTERRUPT FF
REQUEST
VECTOR FETCH
DECODER
ACKK
INTERNAL BUS
RESET
TO PULLUP
KBD4
KBD0
TO PULLUP
SYNCHRONIZER
KEYF
ENABLE
ENABLE
or KBD3