Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet

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SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

A fast startup is enabled upon the detection of a programmed level on one of the 16 wake-up inputs (WKUP) or 

upon an active alarm from the RTC, RTT and USB Controller. The polarity of the 16 wake-up inputs is 

programmable by writing the PMC Fast Start-up Polarity Register (PMC_FSPR).
The fast start-up circuitry, as shown in 

, is fully asynchronous and provides a fast start-up signal to the 

Power Management Controller. As soon as the fast start-up signal is asserted, the embedded 4/8/12 MHz fast RC 

oscillator restarts automatically.
When entering wait mode, the embedded Flash can be placed in one of the low-power modes (deep-power-down 

or standby) depending on the configuration of the FLPM field in the PMC_FSMR. The FLPM field can be 

programmed at anytime and its value will be applied to the next wait mode period.
The power consumption reduction is optimal when configuring 1 (deep-power-down mode) in field FLPM. If 0 is 

programmed (standby mode), the power consumption is slightly higher than in deep-power-down mode.
When programming 2 in field FLPM, the wait mode Flash power consumption is equivalent to that of the active 

mode when there is no read access on the Flash.

Each wake-up input pin and alarm can be enabled to generate a fast start-up event by setting the corresponding 

bit in the Fast Start-up Mode Register (PMC_FSMR).
The user interface does not provide any status for fast start-up, but the user can easily recover this information by 

reading the PIO Controller and the status registers of the RTC, RTT and USB Controller.

The inherent start-up time of the embedded Flash cannot provide a fast start-up of the system.

fast_restart

WKUP15

FSTT15

FSTP15

WKUP1

FSTT1

FSTP1

WKUP0

FSTT0

FSTP0

RTTAL

RTCAL

USBAL

RTT Alarm

RTC Alarm

USB Alarm