MC68HC908AP16CFA MOTOROLA [Motorola, Inc], MC68HC908AP16CFA Datasheet - Page 388

• Manufacturer Part Number: MC68HC908AP16CFA
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Keyboard Interrupt Module (KBI)
20.3 I/O Pins
20.4 Functional Description
Data Sheet
388
KBI0
KBI7
TO PULLUP ENABLE
TO PULLUP ENABLE
KBIE0
KBIE7
Generic Pin Name
KBI0–KBI7
KBI
.
.
.
Figure 20-2. Keyboard Interrupt Block Diagram
The eight keyboard interrupt pins are shared with standard port I/O pins.
The full name of the KBI pins are listed in
name appear in the text that follows.
Writing to the KBIE7–KBIE0 bits in the keyboard interrupt enable register
independently enables or disables each port D pin as a keyboard
interrupt pin. Enabling a keyboard interrupt pin in port D also enables its
internal pull-up device. A logic 0 applied to an enabled keyboard
interrupt pin latches a keyboard interrupt request.
A keyboard interrupt is latched when one or more keyboard pins goes
low after all were high. The MODEK bit in the keyboard status and
control register controls the triggering mode of the keyboard interrupt.
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 20-1. Pin Name Conventions
PTD0/KBI0–PTD7/KBI7
MODEK
Full MCU Pin Name
Go to: www.freescale.com
V
DD
D
CK
CLR
Q
INTERRUPT FF
KEYBOARD
RESET
ACKK
Pin Selected for KBI Function by
Table
MC68HC908AP Family — Rev. 2.5
KBIEx Bit in KBIER
VECTOR FETCH
INTERNAL BUS
KBIE0–KBIE7
DECODER
IMASKK
20-1. The generic pin
SYNCHRONIZER
KEYF
MOTOROLA
Keyboard
Interrupt
Request