NXP Semiconductors MC9S08LG16, Reference Manual

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Chapter 7 Keyboard Interrupt (S08KBIV2)
MC9S08LG32 MCU Series, Rev. 5
130 Freescale Semiconductor
7.1.3 Features
The KBI features include:
• Up to eight keyboard interrupt pins with individual pin enable bits.
• Each keyboard interrupt pin is programmable as falling edge (or rising edge) only, or both falling
edge and low level (or both rising edge and high level) interrupt sensitivity.
• One software enabled keyboard interrupt.
• Exit from low-power modes.
7.1.4 Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
7.1.4.1 KBI in Wait Mode
The KBI continues to operate in wait mode if enabled before executing the WAIT instruction. Therefore,
an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of wait mode if the KBI interrupt is
enabled (KBIE = 1).
7.1.4.2 KBI in Stop Modes
The KBI operates asynchronously in stop3 mode if enabled before executing the STOP instruction.
Therefore, an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of stop3 mode if the KBI
interrupt is enabled (KBIE = 1).
During stop2 mode, the KBI is disabled. In some systems, the pins associated with the KBI may be sources
of wakeup from stop2, see the stop modes section in the
Chapter 3, “Modes of Operation .” Upon wakeup
from stop2 mode, the KBI module will be in the reset state.
7.1.4.3 KBI in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
7.1.5 Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 7-2 .