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MC9S08AC128 Datasheet, PDF (26/42 Pages) Freescale Semiconductor, Inc – 8-Bit Microcontroller | |||
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Chapter 3 Electrical Characteristics and Timing Speciï¬cations
3 Loss of reference frequency is the reference frequency detected internally, which transitions the ICG into self-clocked mode if it
is not in the desired range.
4 Loss of DCO frequency is the DCO frequency detected internally, which transitions the ICG into FLL bypassed external mode
(if an external reference exists) if it is not in the desired range.
5 This parameter is characterized before qualiï¬cation rather than 100% tested.
6 Proper PC board layout procedures must be followed to achieve speciï¬cations.
7 This speciï¬cation applies to the period of time required for the FLL to lock after entering FLL engaged internal or external modes.
If a crystal/resonator is being used as the reference, this speciï¬cation assumes it is already running.
8 Jitter is the average deviation from the programmed frequency measured over the speciï¬ed interval at maximum fICGOUT.
Measurements are made with the device powered by ï¬ltered supplies and clocked by a stable external clock signal. Noise
injected into the FLL circuitry via VDDA and VSSA and variation in crystal oscillator frequency increase the CJitter percentage for
a given interval.
9 See Figure 3-9
Average of Percentage Error
Variable
3V
5V
Figure 3-9. Internal Oscillator Deviation from Trimmed Frequency
MC9S08AC128 Series Data Sheet, Rev. 1
26
Freescale Semiconductor
Preliminary â Subject to Change
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