
Technical Data
MC68HC705J1A — Rev. 4.0
General Description
General Description
1.5.2.3 RC Oscillator
1.5.2.4 External Clock
An external clock from another complementary metal-oxide
semiconductor (CMOS)-compatible device can be connected to the
OSC1 input, with the OSC2 input not connected, as shown in
Figure 1-8. This configuration is possible regardless of whether the
crystal/ceramic resonator or the RC oscillator is enabled.
Figure 1-8. External Clock Connections
1.6 RESET
Applying a logic 0 to the RESET pin forces the MCU to a known startup
state. An internal reset also pulls the RESET pin low. An internal resistor
to VDD pulls the RESET pin high. A steering diode between the RESET
and VDD pins discharges any RESET pin voltage when power is
removed from the MCU. The RESET pin contains an internal Schmitt
trigger to improve its noise immunity as an input. Refer to Section 4. MCU
EXTERNAL
CMOS CLOCK
OS
C
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OSC
2
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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