![Maxim Integrated MAX32660 Скачать руководство пользователя страница 27](http://html1.mh-extra.com/html/maxim-integrated/max32660/max32660_user-manual_1744484027.webp)
MAX32660 User Guide
Maxim Integrated
Page 27 of 195
For the low power modes, the Arm Cortex-M4 with FPU does not execute code. Each low power mode of operation
supports wakeup events that result in the MAX32660 to re-enter
ACTIVE
mode operation. For
SLEEP
mode, wakeup events
include any external or internal interrupt, RTC wakeup, and the Watchdog Interrupt.
DEEPSLEEP
and
BACKUP
mode wakeup
events are limited to any enabled GPIO external interrupt or from an enabled RTC wakeup event.
The Arm Cortex-M family of CPUs have two built-in low power modes, designated
SLEEP
and
DEEPSLEEP
. Implementation of
these low-power modes are speci
fic t th micr c ntr ll r’s sign. h s m s ar nabl using th
Arm Cortex-M4
with FPU System Control Register (SCR). Write register bit SCR
.deepsleep
to select the low power mode as shown in the
pseudocode below.
SCR.sleepdeep = 0; // SLEEP mode enabled
SCR.sleepdeep = 1; //
DEEPSLEEP
mode enabled
Once enabled, the device enters the enabled low power mode when either a WFI (Wait for Interrupt) or WFE (Wait for
Event) instruction is executed.
Immediately before entering any low-power mode, enable the SYSOSC to be used in that low-power mode. If the selected
SYSOSC is disabled in the selected low power mode, it will be enabled upon returning to
ACTIVE
mode.
Refer to the
Cortex
-M4 with FPU
Technical Reference Manual
for more information on the SCR register and the WFI and
WFE instructions.
4.5.1
ACTIVE Mode
This is the highest performance mode. All internal clocks, registers, memory, and peripherals are enabled. The CPU is
running and executing application code. All oscillators are available for application use, if enabled.
Dynamic clocking allows firmware to selectively enable or disable clocks and power to individual peripherals, providing the
optimal mix of high-performance and power conservation. Internal RAM that can be enabled, disabled, or placed in low-
power RAM Retention Mode include data SRAM memory blocks, on-chip cache, and on-chip FIFOs. Refer to
for details on RAM power mode control.
4.5.2
SLEEP Low Power Mode
This is a low power mode that suspends the CPU with a fast wakeup time to
ACTIVE
mode. In
SLEEP
mode, the
microcontroller remains in an
ACTIVE
state with the system clock disabled for the Cortex core. Code execution stops during
SLEEP
mode. All enabled oscillators remain active and the RAM retains state if enabled. Refer to
for
details on enabling and disabling RAM sector data retention.
SLEEP
mode wakeup events include any external or internal interrupt.
The following pseudocode places the device in
SLEEP
mode:
GCR_PMR.mode = 0; // Set mode field to ACTIVE to ensure
DEEPSLEEP
mode is entered
SCR.sleepdeep = 0; //
SLEEP
mode enabled
WFI; // Enter
SLEEP
mode, WFI can be replaced with WFE
Refer to the
Cortex
-M4 with FPU
Technical Reference Manual
for more information on the SCR register and the WFI and
WFE instructions.
4.5.3
DEEPSLEEP Low Power Mode
In
DEEPSLEEP
mode all internal clocks are gated off including the system clock and the Watchdog Timer. The RTC continues
operation, if enabled, during
DEEPSLEEP
. The Arm Cortex-M4 with FPU state and all system and peripheral registers retain
Содержание MAX32660
Страница 4: ...MAX32660 User Guide Maxim Integrated Page 4 of 195 8 UART 84 9 Real Time Clock RTC 96 10 Timers 105...
Страница 7: ...MAX32660 User Guide Maxim Integrated Page 7 of 195 15 Trademarks 195 16 Revision History 195...
Страница 14: ...MAX32660 User Guide Maxim Integrated Page 14 of 195 Figure 2 1 MAX32660 High Level Block Diagram...