Power Management Controller (PMC)
Freescale Semiconductor
5-19
PXR40 Microcontroller Reference Manual, Rev. 1
Figure 5-7. Internal Regulator 1.2V LDO and SMPS diagram
5.5.7
1.2V VDD LVD
A user programmable low voltage detector (LVD) monitors the core supply voltage VDD.
Rising LVD threshold voltage is documented under LVD12 symbol in the
PXR40 Microcontroller Data
Sheet
.
The assertion and negation voltages are adjustable via software by writing to the LVDCTRIM field of the
PMC_TRIMR register, which selects one of the 16 voltages available through the appropriate tapped
output. The reset value of the 4-bit register is “0110”, corresponding to the nominal LVD12 voltage.
When an internal regulator (SMPS or LDO) is used to generate the core voltage supply, it is required to
change the field of the register to “1100” before increasing core logic clock frequency.
LVD scaled voltage can be measured via ADC by selecting the respective channel reported in
.
During this measurement, the output of the LVD is temporarily forced to low level so that false events,
which may be caused by ADC reading, are discarded.
PWM
Controller
VDDREG
Regulator
Select
Decoupling
REGSEL
Vref
Band Gap
VDDREG
VDDREG
VRC1p2
VDDREG
Max 1.2A@1.2V
NJD
2873
VRCTRL
= Trimmed
External Components
PMC 1.2V Regulator
VDD
SI3460
50
k
O
h
m
SMPS MODE
LDO MODE
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
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Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
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