LM3S9B81 Datasheet, PDF (103/1155 Pages) Texas Instruments – Stellaris® LM3S9B81 Microcontroller

Stellaris® LM3S9B81 Microcontroller
6.2.4
Control (MOSCCTL) register. The main oscillator verification error is indicated in the main oscillator
fail status (MOSCFAIL) bit in the Reset Cause (RESC) register. The main oscillator verification circuit
action is described in more detail in “Main Oscillator Verification Circuit” on page 110.
Power Control
The Stellaris^® microcontroller provides an integrated LDO regulator that is used to provide power
to the majority of the microcontroller's internal logic. For power reduction, a non-programmable LDO
may be used to scale the microcontroller’s 3.3 V input voltage to 1.2V. The voltage output has a
minimum voltage of 1.08 V and a maximum of 1.35 V. The LDO delivers up to 60 ma.
Figure 6-4 shows the power architecture.
Note: On the printed circuit board, use the LDO output as the source of VDDC input. In addition,
the LDO requires decoupling capacitors. See “On-Chip Low Drop-Out (LDO) Regulator
Characteristics” on page 1083.
Figure 6-4. Power Architecture
VDDC
Internal
GND
Logic and PLL
VDDC
GND
LDO
Low-Noise
LDO
+3.3V
VDD
VDD
I/O Buffers
GND
GND
VDDA
VDDA
Analog Circuits
(ADC, Analog
Comparators)
GNDA
GNDA
6.2.5
Clock Control
System control determines the control of clocks in this part.
June 29, 2010
103
Texas Instruments-Advance Information