mc9s08rd60fj Freescale Semiconductor, Inc, mc9s08rd60fj Datasheet - Page 123

• Manufacturer Part Number: mc9s08rd60fj
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

9.2 KBI Block Diagram
Figure 9-2
The KBI module allows up to eight pins to act as additional interrupt sources. Four of these pins allow
falling-edge sensing while the other four can be configured for either rising-edge sensing or falling-edge
sensing. The sensing mode for all eight pins can also be modified to detect edges and levels instead of only
edges.
9.3 Keyboard Interrupt (KBI) Module
This on-chip peripheral module is called a keyboard interrupt (KBI) module because originally it was
designed to simplify the connection and use of row-column matrices of keyboard switches. However,
these inputs are also useful as extra external interrupt inputs and as an external means of waking up the
MCU from stop or wait low-power modes.
9.3.1 Pin Enables
The KBIPEn control bits in the KBIxPE register allow a user to enable (KBIPEn = 1) any combination of
KBI-related port pins to be connected to the KBI module. Pins corresponding to 0s in KBIxPE are
general-purpose I/O pins that are not associated with the KBI module.
9.3.2 Edge and Level Sensitivity
Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs in a KBI
module must be at the deasserted logic level.
Freescale Semiconductor
KBIxP0
KBIxP3
KBIxP4
KBIxPn
KBEDG4
KBEDGn
0
1
0
1
shows the block diagram for a KBI module.
S
S
KBIPEn
KBIPE0
KBIPE3
KBIPE4
Figure 9-2 KBI Block Diagram
MC9S08RC/RD/RE/RG
KBIMOD
V
DD
D
CK
CLR
Q
INTERRUPT FF
KEYBOARD
KBACK
RESET
SoC Guide — MC9S08RG60/D Rev 1.10
STOP
SYNCHRONIZER
STOP BYPASS
BUSCLK
KBIE
KBF
KEYBOARD
INTERRUPT
REQUEST
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