MC9S12P128 Datasheet, PDF (522/564 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

Electrical Characteristics
0
1
2
3
N-1
N
t_min1
t_nom
t_max1
t_minN
t_maxN
Figure A-2. Jitter Definitions
The relative deviation of t_nom is at its maximum for one clock period, and decreases towards zero for larger
number of clock periods (N).
Defining the jitter as:
J(N)
=
⎛
max⎜
⎝
1
–
t-N-m-----_{⋅-a--t-nx----}(_o--N--m---)
,
1
–
-Nt--m---_â‹--i-t-n-n---⁽-o-N---m--⁾-
⎞
⎟
⎠
For N < 100, the following equation is a good fit for the maximum jitter:
J(N) = ---^j-¹----
N
J(N)
1
5
10
20
N
Figure A-3. Maximum Bus Clock Jitter Approximation
NOTE
On timers and serial modules a prescaler will eliminate the effect of the jitter
to a large extent.
S12P-Family Reference Manual, Rev. 1.12
522
Freescale Semiconductor