Datasheet

Chapter 3 Electrical Characteristics and Timing Specifications
MC9S08AC128 Series Data Sheet, Rev. 4
26 Freescale Semiconductor
Figure 3-9. Internal Oscillator Deviation from Trimmed Frequency
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 qualification rather than 100% tested.
6
Proper PC board layout procedures must be followed to achieve specifications.
7
This specification 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 specification assumes it is already running.
8
Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum f
ICGOUT
.
Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise
injected into the FLL circuitry via V
DDA
and V
SSA
and variation in crystal oscillator frequency increase the C
Jitter
percentage for
a given interval.
9
See Figure 3-9
Average of Percentage Error
3 V
5 V
Variable