Datasheet

Chapter 7 Keyboard Interrupt (RS08KBIV1)
MC9RS08KA2 Series Data Sheet, Rev. 4
52 Freescale Semiconductor
7.1.2 Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
7.1.2.1 Operation in Wait Mode
The KBI continues to operate in wait mode if enabled before executing the WAIT instruction. Therefore,
an enabled KBI pin (KBPEn = 1) can be used to bring the MCU out of wait mode if the KBI interrupt is
enabled (KBIE = 1).
7.1.2.2 Operation in Stop Mode
The KBI operates asynchronously in stop mode if enabled before executing the STOP instruction.
Therefore, an enabled KBI pin (KBPEn = 1) can be used to bring the MCU out of stop mode if the KBI
interrupt is enabled (KBIE = 1).
7.1.2.3 Operation in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
7.1.3 Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 7-2.
Figure 7-2. Keyboard Interrupt (KBI) Block Diagram
7.2 External Signal Description
The KBI input pins can be used to detect either falling edges, or both falling edge and low level interrupt
requests. The KBI input pins can also be used to detect either rising edges, or both rising edge and high
level interrupt requests.
The signal properties of KBI are shown in Table 7-1.
Table 7-1. Signal Properties
Signal Function I/O
KBIPn Keyboard interrupt pins I
DQ
CK
CLR
V
DD
KBMOD
KBIE
KEYBOARD
INTERRUPT FF
KBACK
RESET
SYNCHRONIZER
KBF
STOP BYPASS
STOP
BUSCLK
KBIPEn
0
1
S
KBEDGn
KBIPE0
0
1
S
KBEDG0
KBIP0
KBIPn
KBI
INTERRUPT
REQUES
T