MC68HC908KX2 MOTOROLA [Motorola, Inc], MC68HC908KX2 Datasheet - Page 127

• Manufacturer Part Number: MC68HC908KX2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

7.7 CONFIG or MOR Options
7.7.1 External Clock Enable (EXTCLKEN)
7.7.2 External Crystal Enable (EXTXTALEN)
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
Four CONFIG or MOR options affect the functionality of the ICG. These
options are:
All CONFIG or MOR options will have a default setting. Refer to
Section 9. Configuration Register (CONFIG)
MOR is used.
External clock enable (EXTCLKEN), when set, enables the ECGON bit
to be set. ECGON turns on the external clock input path through the
PTB6/(OSC1) pin. When EXTCLKEN is clear, ECGON cannot be set
and PTB6/(OSC1) will always perform the PTB6 function.
The default state for this option is clear.
External crystal enable (EXTXTALEN), when set, will enable an amplifier
to drive the PTB7/(OSC2) pin from the PTB6/(OSC1) pin. The amplifier
will drive only if the external clock enable (EXTCLKEN) bit and the
ECGON bit are also set. If EXTCLKEN or ECGON are clear,
PTB7/(OSC2) will perform the PTB7 function. When EXTXTALEN is
clear, PTB7/(OSC2) will always perform the PTB7 function.
EXTXTALEN, when set, also configures the clock monitor to expect an
external clock source in the valid range of crystals (30 kHz to 100 kHz or
1 MHz to 8 MHz). When EXTXTALEN is clear, the clock monitor will
expect an external clock source in the valid range for externally
generated clocks when using the clock monitor (60 Hz to 32 MHz).
1. EXTCLKEN, external clock enable
2. EXTXTALEN, external crystal enable
3. EXTSLOW, slow external clock
4. OSCENINSTOP, oscillator enable in stop
Internal Clock Generator Module (ICG)
Internal Clock Generator Module (ICG)
on how the CONFIG or
CONFIG or MOR Options
Technical Data
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