Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO データシート
製品コード
ATSAM4E-XPRO
17
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
The Supply Controller, zero-power power-on reset, RTT, RTC, backup registers and 32 kHz oscillator (RC or
crystal oscillator selected by software in the Supply Controller) are running. The regulator and the core supply are
off.
crystal oscillator selected by software in the Supply Controller) are running. The regulator and the core supply are
off.
The SAM4E can be awakened from this mode using the WKUP0-15 pins, the supply monitor (SM), the RTT or
RTC wake-up event.
RTC wake-up event.
Backup mode is entered by writing a 1 to the VROFF bit of the Supply Controller Control Register (SUPC_CR) (A
key is needed to write the VROFF bit, refer to the Supply Controller SUPC section of the product datasheet) and
with the SLEEPDEEP bit in the Cortex-M4 System Control Register set to 1. (See the power management
description in the ARM Cortex-M4 Processor section of the product datasheet).
key is needed to write the VROFF bit, refer to the Supply Controller SUPC section of the product datasheet) and
with the SLEEPDEEP bit in the Cortex-M4 System Control Register set to 1. (See the power management
description in the ARM Cortex-M4 Processor section of the product datasheet).
To enter backup mode using the VROFF bit:
Write a 1 to the VROFF bit of SUPC_CR.
To enter backup mode using the WFE instruction:
Write a 1 to the SLEEPDEEP bit of the Cortex-M4 processor.
Execute the WFE instruction of the processor.
In both cases, exit from backup mode happens if one of the following enable wake up events occurs:
WKUPEN0-15 pins (level transition, configurable debouncing)
Supply Monitor alarm
RTC alarm
RTT alarm
5.5.2
Wait Mode
The purpose of wait mode is to achieve very low power consumption while maintaining the whole device in a
powered state for a startup time of less than 10 µs. Current consumption in wait mode is typically 32 µA (total
current consumption) if the internal voltage regulator is used.
powered state for a startup time of less than 10 µs. Current consumption in wait mode is typically 32 µA (total
current consumption) if the internal voltage regulator is used.
In this mode, the clocks of the core, peripherals and memories are stopped. However, the core, peripherals and
memories power supplies are still powered. From this mode, a fast start up is available.
memories power supplies are still powered. From this mode, a fast start up is available.
This mode is entered by setting the WAITMODE bit to 1 in the CKGR_MOR register in conjunction with FLPM = 0
or FLPM = 1 bits of the PMC_FSMR register or by the WFE instruction.
or FLPM = 1 bits of the PMC_FSMR register or by the WFE instruction.
The Cortex-M4 is able to handle external or internal events in order to wake-up the core. This is done by
configuring the external lines WUP0-15 as fast startup wake-up pins (refer to
configuring the external lines WUP0-15 as fast startup wake-up pins (refer to
). RTC or
RTT Alarm and USB wake-up events can be used to wake up the CPU.
To enter wait mode with WAITMODE bit:
Select the 4/8/12 MHz fast RC oscillator as Main Clock.
Set the FLPM field in the PMC Fast Startup Mode Register (PMC_FSMR).
Set Flash Wait State at 0.
Set the WAITMODE bit = 1 in PMC Main Oscillator Register (CKGR_MOR).
Wait for Master Clock Ready MCKRDY = 1 in the PMC Status Register (PMC_SR).
To enter wait mode with WFE:
Select the 4/8/12 MHz fast RC oscillator as Main Clock.
Set the FLPM field in the PMC Fast Startup Mode Register (PMC_FSMR).
Set Flash Wait State at 0.
Set the LPM bit in the PMC Fast Startup Mode Register (PMC_FSMR).
Execute the Wait-For-Event (WFE) instruction of the processor.