MC68HC908RF2 Datasheet, PDF (142/254 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Internal Clock Generator Module (ICG)
forced set when CMF is set, to avoid inadvertent clearing of CMF.
CMON is forced clear when either ICGON or ECGON is clear or
during reset.
1 = Clock monitor output enabled
0 = Clock monitor output disabled
CS — Clock Select Bit
This read/write bit determines which clock will generate the oscillator
output clock (CGMXCLK). This bit can be set when ECGON and
ECGS have been set for at least one bus cycle and can be cleared
when ICGON and ICGS have been set for at least one bus cycle. This
bit is forced set when the clock monitor determines the internal clock
(ICLK) is inactive or when ICGON is clear. This bit is forced clear
when the clock monitor determines that the external clock (ECLK) is
inactive, when ECGON is clear, or during reset.
1 = External clock (ECLK) sources CGMXCLK
0 = Internal clock (ICLK) sources CGMXCLK
ICGON — Internal Clock Generator On Bit
This read/write bit enables the internal clock generator. ICGON can
be cleared when the CS bit has been set and the CMON bit has been
clear for at least one bus cycle. ICGON is forced set when the CMON
bit is set, the CS bit is clear, or during reset.
1 = Internal clock generator enabled
0 = Internal clock generator disabled
ICGS — Internal Clock Generator Stable Bit
This read-only bit indicates when the internal clock generator has
determined that the internal clock (ICLK) is within about 5 percent of
the desired value. This bit is forced clear when the clock monitor
determines the ICLK is inactive, when ICGON is clear, when the ICG
multiplier factor is written, or during reset.
1 = Internal clock is within 5 percent of the desired value.
0 = Internal clock may not be within 5 percent of the desired value.
Advance Information
142
Internal Clock Generator Module (ICG)
MC68HC908RF2 — Rev. 1
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