Freescale Semiconductor MC9S12ZVHL32, Reference Manual

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Chapter 7 S12 Clock, Reset and Power Management Unit (S12CPMU_UHV_V5)
S12ZVHY/S12ZVHL Family Reference Manual, Rev. 1.05
Freescale Semiconductor 277
7.3.2.25 Voltage Regulator Control Register (CPMUVREGCTL)
The CPMUVREGCTL allows to enable or disable certain parts of the voltage regulator.This register must
be configured after system startup.
Read: Anytime
Write: Once in normal modes, anytime in special modes
Module Base + 0x001D
7 6 5 4 3 2 1 0
R 0 0 0 0 0 0
EXTXON INTXON
W
Reset 0 0 0 0 0 0 1 1
= Unimplemented or Reserved
Figure 7-34. Voltage Regulator Control Register (CPMUVREGCTL)
Table 7-30. Effects of writing the EXTXON and INTXON bits
value of
EXTXON
to be written
value of
INTXON
to be written
Write Access
0 0 blocked, no effect
0 1 legal access
1 0 legal access
1 1 blocked, no effect
Table 7-31. CPMUVREGCTL Field Descriptions
Field Description
1
EXTXON
External voltage regulator Enable Bit for VDDX domain — Should be set to 1 if external BJT is present on
the PCB, cleared otherwise.
0 VDDX control loop does not use external BJT
1 VDDX control loop uses external BJT
0
INTXON
Internal voltage regulator Enable Bit for VDDX domain — Should be set to 1 if no external BJT is present on
the PCB, cleared otherwise.
0 VDDX control loop does not use internal power transistor
1 VDDX control loop uses internal power transistor