User Manual
93
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
System Control Unit - Digital Modules (SCU-DM)
• PLL_CON.LOCK = 1
If
f
PLL
is selected as the clock source for system frequency
f
SYS
, the user should enable PLL in normal mode as
default.
Note:
When configuring the PLL frequency
f
PLL
by the P and N dividers the user shall take care that
the limits for
f
REF
,
f
VCO
and
f
sys
are not exceeded.
Prescaler Mode (VCO Bypass Mode)
In Prescaler Mode the reference frequency
f
R
is only divided down by a factor K1.
The output frequency is given by
(7.2)
The Prescaler Mode is selected by the following settings
• PLL_CON.VCOBYP = 1
• PLL_CON.OSCDISC = X
The Prescaler Mode is active when
• PLL_CON.VCOBYP = 1
• PLL_CON.OSCDISC = X
• OSC_CON.OSC2L = 0 if
f
OSC
is provided as
f
R (OSC_CON.OSCSS = 01B)
Freerunning Mode
In Freerunning Mode the base frequency output of the Voltage Controlled Oscillator (VCO)
f
VCObase
is only
divided down by a factor K2.
The output frequency is given by
(7.3)
The Freerunning Mode is enabled by the following settings/conditions
• PLL_CON.VCOBYP = 0 and PLL_CON.LOCK = 0
or
• PLL_CON.VCOBYP = 1 and OSC_CON.OSCSS = 1 and OSC_CON.OSC2L = 1
or
• PLL_CON.VCOBYP = 0 and PLL_CON.OSCDISC = 1
• PLL_CON.VCOBYP = 0
• PLL_CON.OSCDISC = 1
• PLL_CON.LOCK = 0
=
K1
f
PLL
f
R
=
K2
f
PLL
f
VCObase