mc68hc05p18a Freescale Semiconductor, Inc, mc68hc05p18a Datasheet - Page 22

• Manufacturer Part Number: mc68hc05p18a
• Description: Mc68hc05p18a Hcmos Microcontroller Unit
• Manufacturer: Freescale Semiconductor, Inc

General Description
1.5.2.2 Ceramic Resonator
1.5.2.3 External Clock
1.5.3 Reset (RESET)
1.5.4 Port A (PA0–PA7)
Technical Data
NOTE:
In cost-sensitive applications, a ceramic resonator can be used in place
of the crystal. The circuit in
resonator.
The crystal manufacturer’s recommendations should be followed, as the
crystal parameters determine the external component values required to
provide maximum stability and reliable startup.
The load capacitance values used in the oscillator circuit design should
include all stray capacitances. Mount the resonator and components as
close as possible to the pins for startup stabilization and to minimize
output distortion.
An external clock from another CMOS-compatible device can be
connected to the OSC1 input, with the OSC2 input not connected, as
shown in
Driving this input low resets the MCU to a known startup state. As an
output pin, the RESET pin indicates that an internal MCU reset has
occurred. The RESET pin contains an internal Schmitt trigger to improve
its noise immunity. Refer to
Port A is comprised of eight I/O pins (PA0–PA7). The state of any pin is
software programmable and all port A lines are configured as inputs
during power-on or reset. Eight mask options can be chosen to enable
pullups and interrupts (active low) on port A pins (see
Options). Refer to
Interrupts.
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 1-3
Go to: www.freescale.com
General Description
Section 7. Input/Output (I/O) Ports
(b).
Figure 1-3
Section 5.
(a) can be used for a ceramic
Resets.
1.4 Mask
and
MC68HC05P18A
Section 4.