Datasheet

MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor 277
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
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.
Addr. Register Name Bit 7 654321Bit 0
$001A
Keyboard Status
and Control Register
(KBSCR)
Read: 0000KEYF 0
IMASKK MODEK
Write:
ACKK
Reset:00000000
$001B
Keyboard Interrupt Enable
Register
(KBIER)
Read:
KBIE7 KBIE6 KBIE5 KBIE4 KBIE3 KBIE2 KBIE1 KBIE0
Write:
Reset:00000000
= Unimplemented
Figure 18-1. KBI I/O Register Summary
Table 18-1. Pin Name Conventions
KBI
Generic Pin Name
Full MCU Pin Name
Pin Selected for KBI Function by KBIEx
Bit in KBIER
KBI0–KBI7 PTD0/KBI0–PTD7/KBI7 KBIE0–KBIE7