Datasheet

To improve noise immunity and/or to delay reset at power up, the RST input may be connected to
an RC network as shown in Figure 5-2 on page 178.
Figure 5-2. External Circuitry to Extend Power-On Reset
PU
C
1
RST
Stellaris®
R
VDD
R
PU
= 1 kΩ to 100 kΩ
C
1
= 1 nF to 10 µF
If the application requires the use of an external reset switch, Figure 5-3 on page 178 shows the
proper circuitry to use.
Figure 5-3. Reset Circuit Controlled by Switch
PU
C
1
R
S
RST
Stellaris®
R
VDD
Typical R
PU
= 10 kΩ
Typical R
S
= 470 Ω
C
1
= 10 nF
The R
PU
and C
1
components define the power-on delay.
The external reset timing is shown in Figure 23-5 on page 756.
5.2.2.5 Brown-Out Reset (BOR)
A drop in the input voltage resulting in the assertion of the internal brown-out detector can be used
to reset the controller. This is initially disabled and may be enabled by software.
The system 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 a controller interrupt or a system reset.
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.
June 18, 2012178
Texas Instruments-Production Data
System Control
NRND: Not recommended for new designs.