LM3S1621 Datasheet, PDF (181/947 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Stellaris^® LM3S1621 Microcontroller
5.2.1
5.2.2
5.2.2.1
■ System control (Run, Sleep, and Deep-Sleep modes), see “System Control” on page 194
Device Identification
Several read-only registers provide software with information on the microcontroller, such as version,
part number, SRAM size, Flash memory size, and other features. See the DID0 (page 199), DID1
(page 226), DC0-DC9 (page 228) and NVMSTAT (page 245) registers.
Reset Control
This section discusses aspects of hardware functions during reset as well as system software
requirements following the reset sequence.
Reset Sources
The LM3S1621 microcontroller has six sources of reset:
1. Power-on reset (POR) (see page 182).
2. External reset input pin (RST) assertion (see page 182).
3. Internal brown-out (BOR) detector (see page 184).
4. Software-initiated reset (with the software reset registers) (see page 184).
5. A watchdog timer reset condition violation (see page 185).
6. MOSC failure (see page 186).
Table 5-3 provides a summary of results of the various reset operations.
Table 5-3. Reset Sources
Reset Source
Core Reset?
JTAG Reset?
On-Chip Peripherals Reset?
Power-On Reset
Yes
Yes
Yes
RST
Yes
Yes
Yes
Brown-Out Reset
Yes
Yes
Yes
Software System Request
Yes
Yes
Yes
Reset using the SYSRESREQ
bit in the APINT register.
Software System Request
Yes
No
No
Reset using the VECTRESET
bit in the APINT register.
Software Peripheral Reset
No
Yes
Yes^a
Watchdog Reset
Yes
Yes
Yes
MOSC Failure Reset
Yes
Yes
Yes
a. Programmable on a module-by-module basis using the Software Reset Control Registers.
After a reset, the Reset Cause (RESC) register is set with the reset cause. The bits in this register
are sticky and maintain their state across multiple reset sequences, except when an internal POR
is the cause, in which case, all the bits in the RESC register are cleared except for the POR indicator.
A bit in the RESC register can be cleared by writing a 0.
January 21, 2012
181
Texas Instruments-Production Data