mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 691

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

A.6.3
A.6.3.1
With each transition of the clock f
voltage to the VCO is adjusted accordingly.The adjustment is done continuously with no abrupt changes
in the clock output frequency. Noise, voltage, temperature and other factors cause slight variations in the
control loop resulting in a clock jitter. This jitter affects the real minimum and maximum clock periods as
illustrated in
The relative deviation of t
number of clock periods (N).
Defining the jitter as:
Freescale Semiconductor
0
Phase Locked Loop
Figure
Jitter Information
t
min1
t
nom
t
max1
A-4.
nom
1
is at its maximum for one clock period, and decreases towards zero for larger
J N
( )
S12XS Family Reference Manual, Rev. 1.10
cmp
, the deviation from the reference clock f
=
Figure A-4. Jitter Definitions
max 1
2
⎛
⎜
⎝
–
t
---------------------- -
N t
max
t
minN
t
⋅
maxN
nom
( )
N
3
,
1
–
---------------------- -
N t
t
min
⋅
nom
( )
N
⎞
⎟
⎠
N-1
ref
is measured and input
Electrical Characteristics
N
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