MC9S08QD4_07 Datasheet, PDF (139/202 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

Keyboard Interrupts (S08KBIV2)
10.1.1 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.
10.1.2 Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
10.1.2.1 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).
10.1.2.2 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 either stop1 or stop2 mode, the KBI is disabled. In some systems, the pins associated with the KBI
may be sources of wakeup from stop1 or stop2, see the stop modes section in the Modes of Operation
chapter. Upon wake-up from stop1 or stop2 mode, the KBI module will be in the reset state.
10.1.2.3 KBI in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
10.1.3 Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 10-2.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
139