MC908AP16CFAE Datasheet, PDF (279/324 Pages) Freescale Semiconductor, Inc – Table of Contents

Chapter 18
Keyboard Interrupt Module (KBI)
18.1 Introduction
The keyboard interrupt module (KBI) provides eight independently maskable external interrupts which are
accessible via PTD0–PTD7. When a port pin is enabled for keyboard interrupt function, an internal 30kΩ
pullup device is also enabled on the pin.
18.2 Features
Features of the keyboard interrupt module include the following:
• Eight keyboard interrupt pins with pullup devices
• Separate keyboard interrupt enable bits and one keyboard interrupt mask
• Programmable edge-only or edge- and level- interrupt sensitivity
• Exit from low-lower modes
Addr.
$001A
$001B
Register Name
Keyboard Status ^Read:
and Control Register Write:
(KBSCR) Reset:
Keyboard Interrupt Enable ^Read:
Register Write:
(KBIER) Reset:
Bit 7
0
0
KBIE7
0
6
5
0
0
0
0
KBIE6 KBIE5
0
0
= Unimplemented
4
0
0
KBIE4
0
3
KEYF
0
KBIE3
0
2
0
ACKK
0
KBIE2
0
Figure 18-1. KBI I/O Register Summary
1
IMASKK
0
KBIE1
0
Bit 0
MODEK
0
KBIE0
0
18.3 I/O Pins
The eight keyboard interrupt pins are shared with standard port I/O pins. The full name of the KBI pins
are listed in Table 18-1. The generic pin name appear in the text that follows.
Table 18-1. Pin Name Conventions
KBI
Generic Pin Name
KBI0–KBI7
Full MCU Pin Name
PTD0/KBI0–PTD7/KBI7
Pin Selected for KBI Function by KBIEx
Bit in KBIER
KBIE0–KBIE7
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
277