Datasheet

General Description
Pin Functions
MC68HC908LJ24/LK24 — Rev. 2.1 Data Sheet
Freescale Semiconductor General Description 45
1.6.3 LCD Bias Voltage (V
LCD
)
V
LCD
is the bias voltage supply for the LCD driver module. Connect the
V
LCD
pin to the same voltage potential as V
DD
. For maximum noise
immunity, route V
LCD
via a separate trace and place bypass capacitors
as close as possible to the package. See Section 17. Liquid Crystal
Display (LCD) Driver.
1.6.4 Oscillator Pins (OSC1 and OSC2)
The OSC1 and OSC2 pins are the connections for the on-chip oscillator
circuit. The OSC1 pin contains a schmitt-trigger and a spike filter for
improved EMC performance. See Section 7. Oscillator (OSC).
1.6.5 External Reset Pin (RST)
A logic 0 on the RST pin forces the MCU to a known start-up state. RST
is bidirectional, allowing a reset of the entire system. It is driven low when
any internal reset source is asserted. A Schmitt-trigger and a spike filter
is associated with this pin so that the device is more robust to EMC
noise. This pin also contains an internal pullup resistor. See 9.4 Reset
and System Initialization.
1.6.6 External Interrupt Pin (IRQ)
IRQ
is an asynchronous external interrupt pin. This pin contains an
internal pullup resistor. See Section 19. External Interrupt (IRQ).
1.6.7 External Filter Capacitor Pin (CGMXFC)
CGMXFC is an external filter capacitor connection for the CGM.
See 8.4.9 CGM External Connections.
1.6.8 ADC Voltage High Reference Pin (V
REFH
)
V
REFH
is the voltage input pin for the ADC voltage high reference.
See 16.7.4 ADC Voltage Reference High Pin (V
REFH
).