Datasheet
37
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
8. System Controller
The System Controller is a set of peripherals which allow handling of key elements of the system such as but not
limited to power, resets, clocks, time, interrupts, and watchdog.
The System Controller User Interface also embeds the registers allowing to configure the Matrix and a set of
registers configuring the SDR-SDRAM chip select assignment.
8.1 System Controller and Peripherals Mapping
Please refer to Figure 7-1 “SAM3X/A Product Mapping” on page 31 .
All the peripherals are in the bit band region and are mapped in the bit band alias region.
8.2 Power-on-Reset, Brownout and Supply Monitor
The SAM3X/A embeds three features to monitor, warn and/or reset the chip:
Power-on-Reset on VDDBU
Brownout Detector on VDDCORE
Supply Monitor on VDDUTMI
8.2.1 Power-on-Reset on VDDBU
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
Section 45. “Electrical Characteristics”.
8.2.2 Brownout Detector on VDDCORE
The Brownout Detector monitors VDDCORE. It is active by default. It can be deactivated by software 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 information, refer to
Section 16. “Supply Controller (SUPC)” and Section 45. “Electrical Characteristics”.
8.2.3 Supply Monitor on VDDUTMI
The Supply Monitor monitors VDDUTMI. It is not active by default. It can be activated by software and is fully
programmable with 16 steps for the threshold (between 1.9V to 3.4V). It is controlled by the Supply Controller
(SUPC). 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 Section 16. “Supply Controller (SUPC)” and Section 45. “Electrical
Characteristics”.