SAM7X256_14 Datasheet, PDF (57/662 Pages) ATMEL Corporation – ARM-based Flash MCU

This feature allows the Reset Controller to shape the NRST pin level, and thus to guarantee that the NRST line is driven
low for a time compliant with potential external devices connected on the system reset.
13.2.3 Brownout Manager
Brownout detection prevents the processor from falling into an unpredictable state if the power supply drops below a
certain level. When VDDCORE drops below the brownout threshold, the brownout manager requests a brownout reset
by asserting the bod_reset signal.
The programmer can disable the brownout reset by setting low the bod_rst_en input signal, i.e.; by locking the
corresponding general-purpose NVM bit in the Flash. When the brownout reset is disabled, no reset is performed.
Instead, the brownout detection is reported in the bit BODSTS of RSTC_SR. BODSTS is set and clears only when
RSTC_SR is read.
The bit BODSTS can trigger an interrupt if the bit BODIEN is set in the RSTC_MR.
At factory, the brownout reset is disabled.
Figure 13-3. Brownout Manager
bod_rst_en
bod_reset
brown_out
RSTC_SR
BODSTS
RSTC_MR
BODIEN
Other
interrupt
sources
rstc_irq
SAM7X Series [DATASHEET] 57
6120K–ATARM–11-Feb-14