ATSAM3U_10 ATMEL [ATMEL Corporation], ATSAM3U_10 Datasheet - Page 38

• Manufacturer Part Number: ATSAM3U_10
• Description: AT91ARM Cortex M3-based Microcontrollers
• Manufacturer: ATMEL [ATMEL Corporation]

10.1
10.2
10.2.1
10.2.2
10.2.3
10.3
10.4
38
System Controller and Peripheral Mapping
Power-on-Reset, Brownout and Supply Monitor
Reset Controller
Supply Controller
SAM3U Series
Power-on-Reset on VDDBU
Brownout Detector on VDDCORE
Supply Monitor on VDDUTMI
Please refer to
All the peripherals are in the bit band region and are mapped in the bit band alias region.
The SAM3U embeds three features to monitor, warn and/or reset the chip:
The Power-on-Reset monitors VDDBU. It is always activated and monitors voltage at start up
but also during power down. If VDDBU goes below the threshold voltage, the entire chip is reset.
For more information, refer to the “Electrical Characteristics” section of the datasheet.
The Brownout Detector monitors VDDCORE. It is active by default. It can be deactivated by soft-
ware through the Supply Controller (SUPC_MR). It is especially recommended to disable it
during low-power modes such as wait or sleep modes.
If VDDCORE goes below the threshold voltage, the reset of the core is asserted. For more infor-
mation, refer to the “Supply Controller” and “Electrical Characteristics” sections of the product
datasheet.
The Supply Monitor monitors VDDUTMI. It is not active by default. It can be activated by soft-
ware and is fully programmable with 16 steps for the threshold (between 1.9V to 3.4V). It is
controlled by the Supply Controller. A sample mode is possible. It allows to divide the supply
monitor power consumption by a factor of up to 2048. For more information, refer to the “Supply
Controller” and “Electrical Characteristics” sections of the product datasheet.
The Reset Controller is capable to return to the software the source of the last reset, either a
general reset, a wake-up reset, a software reset, a user reset or a watchdog reset.
The Reset Controller controls the internal resets of the system and the NRST pin output. It is
capable to shape a reset signal for the external devices, simplifying to a minimum connection of
a push-button on the NRST pin to implement a manual reset.
The Supply Controller controls the power supplies of each section of the processor and the
peripherals (via Voltage regulator control).
The Supply Controller has its own reset circuitry and is clocked by the 32 kHz Slow clock
generator.
The reset circuitry is based on a zero-power power-on reset cell. The zero-power power-on reset
allows the Supply Controller to start properly.
• Power-on-Reset on VDDBU
• Brownout Detector on VDDCORE
• Supply Monitor on VDDUTMI
Figure 8-1“SAM3U Memory Mapping” on page 30
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6430CS–ATARM–09-Apr-10