Motorola MC9S12DG128B, MC9S12DT128B, MC9S12DB128B, MC9S12DJ128B manual = max ⎜ ⋅ t nom

MC9S12DT128B Device User Guide — V01.07

0 1 2 3 N-1 N

tmin1

tnom

tmax1

tminN

tmaxN

Figure A-3 Jitter Definitions

The relative deviation of tnom is at its maximum for one clock period, and decreases towards zero for larger number of clock periods (N).

Defining the jitter as:

⎛	1	tmax(N)	,	tmin	(N)	⎞
J(N) = max⎜		–---------------------		1 –--------------------		⎟
⎝		N ⋅ tnom		N ⋅ tnom		⎠

For N < 100, the following equation is a good fit for the maximum jitter:

J(N) = j1 + j

------- 2

N

J(N)

1 5 10 20 N

Figure A-4 Maximum bus clock jitter approximation

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