MC908AP32CFBE Datasheet, PDF (279/324 Pages) Freescale Semiconductor, Inc – The following revision history table summarizes changes contained in this document. For your convenience, the page number designators have been linked to the appropriate location.

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