s908ey16g2vfar Freescale Semiconductor, Inc, s908ey16g2vfar Datasheet - Page 103

• Manufacturer Part Number: s908ey16g2vfar
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

8.6.3 Slow External Clock (EXTSLOW)
Slow external clock (EXTSLOW), when set, will decrease the drive strength of the oscillator amplifier,
enabling low-frequency crystal operation (30 kHz–100 kHz) if properly enabled with the external clock
enable (EXTCLKEN) and external crystal enable (EXTXTALEN) bits. When clear, EXTSLOW enables
high-frequency crystal operation (1 MHz to 8 MHz or 8 MHz to 32 MHz depending on RNGSEL).
EXTSLOW, when set, also configures the clock monitor to expect an external clock source that is slower
than the low-frequency base clock (60 Hz to 307.2 kHz). When EXTSLOW is clear, the clock monitor will
expect an external clock faster than the low-frequency base clock (307.2 kHz to 32 MHz).
The default state for this option is clear.
8.6.4 Oscillator Enable In Stop (OSCENINSTOP)
Oscillator enable in stop (OSCENINSTOP), when set, will enable the ICG to continue to generate clocks
(either CGMXCLK, CGMOUT, or TBMCLK) in stop mode. This function is used to keep the timebase
running while the rest of the microcontroller stops. When OSCENINSTOP is clear, all clock generation
will cease and CGMXCLK, CGMOUT, and TBMCLK will be forced low during stop mode.
The default state for this option is clear.
8.7 Input/Output (I/O) Registers
The ICG contains five registers. These registers are:
Several of the bits in these registers have interaction where the state of one bit may force another bit to
a particular state or prevent another bit from being set or cleared. A summary of this interaction is shown
in
Freescale Semiconductor
Table
1. ICG control register, ICGCR
2. ICG multiplier register, ICGMR
3. ICG trim register, ICGTR
4. ICG DCO divider control register, ICGDVR
5. ICG DCO stage control register, ICGDSR
8-4.
MC68HC908EY16A • MC68HC908EY8A Data Sheet, Rev. 1
Input/Output (I/O) Registers
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