LM3S6C11 Datasheet, PDF (172/828 Pages) Texas Instruments – Stellaris® LM3S6C11 Microcontroller

System Control
OBSOLETE: TI has discontinued production of this device.
Figure 5-2. External Circuitry to Extend Power-On Reset
VDD
Stellaris®
R_PU
RST
C₁
R_PU = 1 kΩ to 100 kΩ
C₁ = 1 nF to 10 µF
If the application requires the use of an external reset switch, Figure 5-3 on page 172 shows the
proper circuitry to use.
Figure 5-3. Reset Circuit Controlled by Switch
VDD
Stellaris®
R_PU
RST
R_S
C₁
5.2.2.5
Typical R_PU = 10 kΩ
Typical R_S = 470 Ω
C₁ = 10 nF
The R_PU and C₁ components define the power-on delay.
The external reset timing is shown in Figure 20-7 on page 779.
Brown-Out Reset (BOR)
The microcontroller provides a brown-out detection circuit that triggers if the power supply (V_DD)
drops below a brown-out threshold voltage (V_BTH). If a brown-out condition is detected, the system
may generate an interrupt or a system reset. The default condition is to reset the microcontroller.
Brown-out resets are controlled with the Power-On and Brown-Out Reset Control (PBORCTL)
register. The BORIOR bit in the PBORCTL register must be set for a brown-out condition to trigger
a reset; if BORIOR is clear, an interrupt is generated. When a Brown-out condition occurs during a
Flash PROGRAM or ERASE operation, a full system reset is always triggered without regard to the
setting in the PBORCTL register.
The brown-out reset sequence is as follows:
1. When V_DD drops below V_BTH, an internal BOR condition is set.
172
July 24, 2012
Texas Instruments-Production Data