MC68HC705V12CFN MOTOROLA [Motorola, Inc], MC68HC705V12CFN Datasheet - Page 31

• Manufacturer Part Number: MC68HC705V12CFN
• Description: The Motorola microcontroller
• Manufacturer: MOTOROLA [Motorola, Inc]

1.7.5.2 Ceramic Resonator Oscillator
1.7.5.3 External Clock
1.7.6 RESET
1.7.7 IRQ/V
MC68HC705V12
MOTOROLA
PP
NOTE:
—
Rev. 3.0
In cost-sensitive applications, a ceramic resonator can be used in place
of the crystal. The circuit in
resonator.
The resonator manufacturer’s recommendations should be followed, as
the resonator parameters determine the external component values
required for maximum stability and reliable starting.
The load capacitance values used in the oscillator circuit design should
include all stray capacitances. The ceramic resonator and components
should be mounted as close as possible to the pins for startup
stabilization and to minimize output distortion and radiated emissions.
An external clock from another CMOS-compatible device can be
connected to the OSC1 input. The OSC2 pin should be left unconnected,
as shown in
This pin can be used as an input to reset the MCU to a known startup
state by pulling it to the low state. The RESET pin contains an internal
Schmitt trigger to improve its noise immunity as an input. The RESET pin
has an internal pulldown device that pulls the RESET pin low when there
is a COP watchdog reset, power-on reset (POR), illegal address reset,
a disabled STOP instruction reset, or an internal low-voltage reset. Refer
to
This input pin drives the asynchronous maskable interrupt request (IRQ)
function of the CPU. The IRQ interrupt function has a programmable
mask option to select either negative edge-sensitive triggering or both
negative edge-sensitive and low level-sensitive triggering. The IRQ input
requires an external resistor to V
Section 5.
Figure
Resets.
General Description
1-3(b).
Figure
DD
1-3(a) can be used for a ceramic
for wire-OR operation, if desired. If
Functional Pin Descriptions
Advance Information
General Description
31