MC9S08AC16_08 Datasheet, PDF (159/344 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

Chapter 9
Keyboard Interrupt (S08KBIV1)
9.1 Introduction
The MC9S08AC16 Series has one KBI module with seven keyboard interrupt inputs that are shared with
port D and port G pins. See Chapter 2, “Pins and Connections,” for more information about the logic and
hardware aspects of these pins.
9.2 Keyboard Pin Sharing
The KBI input KBIP6 shares a common pin with PTD3 and AD11, and KBI input KBIP5 shares a common
pin with PTD2 and AD10. The sharing of each of these inputs with port and ADC functions operates in
the same way as described above for KBIP7.
The KBI inputs KBIP4 – KBIP0 are shared on common pins with PTG4 – PTG0. These pins all operate
in the same way as described above for KBIP7 except that none are shared with an ADC input.
KBIP3 – KBIP0 are always falling-edge/low-level sensitive. KBIP7 – KBIP4 can be configured for
rising-edge/high-level or for falling-edge/low-level sensitivity. When any of the inputs KBIP7 – KBIP0 are
enabled and configured to detect rising edges/high levels, and the pin pullup is enabled through the
corresponding port pullup enable bit for that pin, a pulldown resistor rather than a pullup resistor is enabled
on the pin.
9.3 Features
The keyboard interrupt (KBI) module features include:
• Four falling edge/low level sensitive
• Four falling edge/low level or rising edge/high level sensitive
• Choice of edge-only or edge-and-level sensitivity
• Common interrupt flag and interrupt enable control
• Capable of waking up the MCU from stop3, stop2, stop1, or wait mode
MC9S08AC16 Series Data Sheet, Rev. 6
Freescale Semiconductor
159