Analog Circuits
I/O Buffers
LDO Voltage
Regulator
Internal
Logic and PLL
GND
GNDA
GNDA
VDDA
VDDA
VDDC
VDDC
3.3 V
GND
GND
GND
VDD
VDD
3.3 V
Functional Description
202
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
System Control
4.1.3.2
Main Oscillator Verification Failure
The MSP432E4 microcontroller provides a main oscillator verification circuit that generates an error
condition if the oscillator is running too fast or too slow. If the main oscillator verification circuit is enabled
and a failure occurs, either a POR is generated and control is transferred to the NMI handler, or an
interrupt is generated. The MOSCIM bit in the MOSCCTL register determines which action occurs. In
either case, the system clock source is automatically switched to the PIOSC. If a MOSC failure reset
occurs, the NMI handler is used to address the main oscillator verification failure, because the necessary
code can be removed from the general reset handler, speeding up reset processing. The detection circuit
is enabled by setting the CVAL bit in the Main Oscillator Control (MOSCCTL) register. The main oscillator
verification error is indicated in the main oscillator fail status (MOSCFAIL) bit in the RESC register. The
main oscillator verification circuit action is described in more detail in
.
4.1.4 Power Control
An integrated LDO regulator provides power to most of the internal logic of the microcontroller.
shows the power architecture. The voltage output has a maximum voltage of 1.2 V. See
for more information on the LDO operation.
An external LDO may not be used.
NOTE:
VDDA must be supplied with 3.3 V, or the microcontroller does not function properly. VDDA
is the supply for all of the analog circuitry on the device, including the clock circuitry.
A
The VDDA voltage source is typically connected to a filtered voltage source or regulator.
Figure 4-4. Power Architecture