User Manual
94
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
General Configuration Overview
The divider values and all necessary other values can be configured via the PLL configuration registers.
In TLE984xQX the P factor can be programmed to the values 4, 5 or 6.
shows all possible values for
the P factor and gives the valid input frequency range
f
R
for the P divider dependent configuration and the
resulting
f
P
frequency values which are directly linked to
f
REF
:
Note:
Of course the whole range in between two f
R
columns in the above table is allowed if parameter f
VCO
is kept within the specified limits. The min. and max. limits of f
P
result out of the parameter
specification of f
REF
and its variation as f
P
is directly linked to f
REF
.
The P-divider output frequency
f
P
is fed to the Voltage Controlled Oscillator (VCO).The VCO is a part of PLL with
a feedback path. A divider in the feedback path (N divider) divides the VCO frequency. The
f
VCO
by:
The following table shows the possible N loop division rates and gives the valid output frequency range for
f
depending on N and the VCO frequency range. All not allowed combinations are related to the fact that using
them the limits of parameter
f
REF
are violated:
Table 33 P-Divider
Factor
P
f
P
for
f
R
=
4 MHz
5 MHz
6 MHz
4
1
1.25
not allowed
5
0.8
1
1.2
not allowed
0.83
1
Range
min. VCO tunning
range frequency
max. VCO tunning
range frequency
VCO freerunning frequency
Unit
see
f
VCO_min
see
f
VCO_max
see
f
VCOfree
1)
is the free running operation frequency of the PLLVCO, when no input reference clock is available.
MHz
Table 35 N Loop Division Rates
N
f
DIV
for
f
VCO
=
75
96
112
136
160
1-47
not accessible
48
not allowed not allowed not allowed not allowed not allowed
50
not allowed not allowed not allowed not allowed not allowed
51
not allowed not allowed not allowed not allowed not allowed
52
not allowed not allowed not allowed not allowed not allowed
not allowed not allowed not allowed not allowed not allowed
1.25
not allowed not allowed not allowed not allowed
1.12
not allowed not allowed not allowed not allowed
72
1.04
not allowed not allowed not allowed not allowed
1.00
not allowed not allowed not allowed not allowed