MC908JL8CDWE Datasheet, PDF (167/212 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 13
Keyboard Interrupt Module (KBI)
13.1 Introduction
The keyboard interrupt module (KBI) provides eight independently maskable external interrupts which are
accessible via PTA0–PTA7. When a port pin is enabled for keyboard interrupt function, an internal pull-up
device is also enabled on the pin.
13.2 Features
Features of the keyboard interrupt module include the following:
• Eight keyboard interrupt pins with pull-up devices
• Separate keyboard interrupt enable bits and one keyboard interrupt mask
• Programmable edge-only or edge- and level- interrupt sensitivity
• Exit from low-power modes
Addr.
$001A
$001B
Register Name
Keyboard Status and ^Read:
Control Register Write:
(KBSCR) _Reset:
Keyboard Interrupt ^Read:
Enable 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 13-1. KBI I/O Register Summary
1
IMASKK
0
KBIE1
0
Bit 0
MODEK
0
KBIE0
0
13.3 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 13-1. The generic pin name appear in the text that follows.
Table 13-1. Pin Name Conventions
KBI
Generic Pin Name
Full MCU Pin Name
Pin Selected for KBI Function by KBIEx
Bit in KBIER
KBI0–KBI5
PTA0/KBI0–PTA5/KBI5
KBIE0–KBIE5
KBI6
OSC2/RCCLK/PTA6/KBI6⁽¹⁾
KBIE6
KBI7
PTA7/KBI7
KBIE7
1. PTA6/KBI6 is only available when OSCSEL=0 at $FFD0 (RC option), and PTA6EN=1 at $000D.
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor
167