The user program controls the power state of the application processor subsystem and can be in one of the five
modes described in
Table 9-2. User Program Modes
APPLICATION PROCESSOR
DESCRIPTION
MCU active mode
MCU executing code at 80-MHz state rate
MCU sleep mode
The MCU clocks are gated off in sleep mode and the entire state of the device is retained. Sleep mode
offers instant wakeup. The MCU can be configured to wake up by an internal fast timer or by activity
from any GPIO line or peripheral.
MCU LPDS mode
State information is lost and only certain MCU-specific register configurations are retained. The MCU
can wake up from external events or by using an internal timer. (The wake-up time is less than 3 ms.)
Certain parts of memory can be retained while the MCU is in LPDS mode. The amount of memory
retained is configurable. Users can choose to preserve code and the MCU-specific setting. The MCU
can be configured to wake up using the RTC timer or by an external event on specific GPIOs as the
wake-up source.
MCU hibernate mode
The lowest power mode in which all digital logic is power-gated. Only a small section of the logic directly
powered by the input supply is retained. The RTC keeps running and the MCU supports wakeup from
an external event or from an RTC timer expiry. Wake-up time is longer than LPDS mode at about 15 ms
plus the time to load the application from serial Flash, which varies according to code size. In this mode,
the MCU can be configured to wake up using the RTC timer or external event on a GPIO .
MCU shutdown mode
The lowest power mode system-wise. All device logics are off, including the RTC. The wake-up time in
this mode is longer than hibernate at about 1.1 s. To enter or exit the shutdown mode, the state of the
nRESET line is changed (low to shut down, high to turn on).
(1)
Modes are listed in order of power consumption, with highest power modes listed first.
The NWP can be active or in LPDS mode and takes care of its own mode transitions. When there is no network
activity, the NWP sleeps most of the time and wakes up only for beacon reception (see
Table 9-3. Networking Subsystem Modes
NETWORK PROCESSOR MODE
DESCRIPTION
Network active mode
(processing layer 3, 2, and 1)
Transmitting or receiving IP protocol packets
Network active mode
(processing layer 2 and 1)
Transmitting or receiving MAC management frames; IP processing not required.
Network active listen mode
Special power optimized active mode for receiving beacon frames (no other frames supported)
Network connected Idle
A composite mode that implements 802.11 infrastructure power save operation. The CC3220MODx
and CC3220MODAx NWPs automatically goes into LPDS mode between beacons and then wakes
to active listen mode to receive a beacon and determine if there is pending traffic at the AP. If not,
the NWP returns to LPDS mode and the cycle repeats.
Network LPDS mode
Low-power state between beacons in which the state is retained by the NWP, allowing for a rapid
wake up.
Network disabled
The network is disabled
The operation of the application and network processor ensures that the module remains in the lowest power
mode most of the time to preserve battery life.
The following examples show the use of the power modes in applications:
• A product that is continuously connected to the network in the 802.11 infrastructure power-save mode but
sends and receives little data spends most of the time in connected idle, which is a composite of receiving a
beacon frame and waiting for the next beacon.
• A product that is not continuously connected to the network but instead wakes up periodically (for example,
every 10 minutes) to send data, spends most of the time in hibernate mode, jumping briefly to active mode to
transmit data.
SWRS206E – MARCH 2017 – REVISED MAY 2021
54
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