MC68HC908LK24CFQ Freescale Semiconductor, MC68HC908LK24CFQ Datasheet - Page 409

• Manufacturer Part Number: MC68HC908LK24CFQ
• Description: IC MCU 24K FLASH 8MHZ SPI 80-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LK24CFQ

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, IRSCI, SPI
• Peripherals: LCD, LVD, POR, PWM
• Number Of I /o: 40
• Program Memory Size: 24KB (24K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

20.5 Functional Description
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor
KBI0
KBI7
TO PULLUP ENABLE
TO PULLUP ENABLE
KBIE0
KBIE7
.
.
.
Figure 20-2. Keyboard Interrupt Block Diagram
Writing to the KBIE7–KBIE0 bits in the keyboard interrupt enable register
independently enables or disables a port A or port D pin as a keyboard
interrupt pin. Enabling a keyboard interrupt pin in port A or port D also
enables its internal pullup 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.
•
•
If the keyboard interrupt is edge-sensitive only, a falling edge on a
keyboard pin does not latch an interrupt request if another
keyboard pin is already low. To prevent losing an interrupt request
on one pin because another pin is still low, software can disable
the latter pin while it is low.
If the keyboard interrupt is falling edge- and low level-sensitive, an
interrupt request is present as long as any keyboard pin is low.
Keyboard Interrupt Module (KBI)
MODEK
V
DD
D
CK
CLR
Q
INTERRUPT FF
KEYBOARD
RESET
ACKK
VECTOR FETCH
Keyboard Interrupt Module (KBI)
INTERNAL BUS
DECODER
IMASKK
SYNCHRONIZER
Functional Description
KEYF
Data Sheet
KEYBOARD
INTERRUPT
REQUEST
409