MC68HC908LJ24 Datasheet, PDF (407/464 Pages) Motorola, Inc – Microcontrollers

Data Sheet — MC68HC908LJ24
Section 20. Keyboard Interrupt Module (KBI)
20.1 Contents
20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
20.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
20.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
20.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .409
20.5.1 Keyboard Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
20.6 Keyboard Interrupt Registers . . . . . . . . . . . . . . . . . . . . . . . . . 412
20.6.1 Keyboard Status and Control Register. . . . . . . . . . . . . . . . 412
20.6.2 Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . 413
20.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
20.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .414
20.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .414
20.8 Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . 414
20.2 Introduction
The keyboard interrupt module (KBI) provides eight independently
maskable external interrupts which are accessible via PTA0–PTA3 and
PTD4–PTD7. When a port pin is enabled for keyboard interrupt function
(except PTD6 and PTD7), an internal 30kΩ pullup device is also enabled
on the pin.
NOTE:
PTD6/KBI6/SCL–PTD7/KBI7/SDA pins do not have internal pullup
devices. These two pins are open-drain when configured as outputs.
User should connect pullup devices when using these two pins for KBI
function.
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor
Keyboard Interrupt Module (KBI)
Data Sheet
407