LM3S1969 Datasheet, PDF (239/677 Pages) Texas Instruments – Stellaris® LM3S1969 Microcontroller

OBSOLETE: TI has discontinued production of this device.
Stellaris^® LM3S1969 Microcontroller
Hibernation module registers. The delay allows the crystal to power up and stabilize. If an oscillator
is used for the clock source, no delay is needed.
Figure 6-2. Clock Source Using Crystal
Input
Voltage
Regulator
or Switch
IN OUT
EN
Stellaris Microcontroller
VDD
XOSC0
X₁
R_L
XOSC1
C₁
C₂
R_PU
Open drain
external wake
up circuit
HIB
WAKE
VBAT
GND
3V
Battery
Note:
X₁ = Crystal frequency is f_{XOSC_XTAL}.
C_1,2 = Capacitor value derived from crystal vendor load capacitance specifications.
R_L = Load resistor is R_{XOSC_LOAD}.
R_PU = Pull-up resistor (1 M½).
See “Hibernation Module” on page 636 for specific parameter values.
Figure 6-3. Clock Source Using Dedicated Oscillator
Input
Voltage
Regulator
or Switch
IN OUT
EN
Clock
Source
(f_{EXT_OSC})
N.C.
Stellaris Microcontroller
VDD
XOSC0
XOSC1
6.3.3
R_PU
Open drain
external wake
up circuit
HIB
WAKE
VBAT
GND
3V
Battery
Note: R_PU = Pull-up resistor (1 M½).
Battery Management
The Hibernation module can be independently powered by a battery or an auxiliary power source.
The module can monitor the voltage level of the battery and detect when the voltage drops below
V_LOWBAT. When this happens, an interrupt can be generated. The module can also be configured
July 24, 2012
239
Texas Instruments-Production Data