Datasheet

ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/ADE7569
Rev. B | Page 39 of 152
TRANSITIONING BETWEEN OPERATING MODES
The operating mode of the ADE7116/ADE7156/ADE7166/
ADE7169/ADE7566/ADE7569 is determined by the power
supply connected to V
SWOUT
. Therefore, changes in the power
supply, such as when V
SWOUT
switches from V
DD
to V
BAT
or when
V
SWOUT
switches to V
DD
, alter the operating mode. This section
describes events that change the operating mode.
Automatic Battery Switchover (PSM0 to PSM1)
If any of the enabled battery switchover events occurs (see the
Battery Switchover section), V
SWOUT
switches to V
BAT
. This
switchover results in a transition from PSM0 to PSM1 operating
mode. When battery switchover occurs, the analog circuitry
used in the ADE energy measurement DSP is disabled. To
reduce power consumption, the user code can initiate a
transition to PSM2.
Entering Sleep Mode (PSM1 to PSM2)
To reduce power consumption when VSWOUT is connected to
V
BAT
, user code can initiate sleep mode, PSM2, by setting Bit 4
in the power control SFR (POWCON, Address 0xC5) to shut
down the MCU core. Events capable of waking the MCU can be
enabled (see the 3.3 V Peripherals and Wake-Up Events section).
Servicing Wake-Up Events (PSM2 to PSM1)
The ADE7116/ADE7156/ADE7166/ADE7169/ADE7566/
ADE7569 may need to wake up from PSM2 mode to service
wake-up events (see the 3.3 V Peripherals and Wake-Up Events).
PSM1 code execution begins at the power-on reset vector. After
servicing the wake-up event, the ADE7116/ADE7156/ADE7166/
ADE7169/ADE7566/ADE7569 can return to PSM2 mode by
setting Bit 4 in the power control SFR (POWCON, Address
0xC5) to shut down the MCU core.
Automatic Switch to V
DD
(PSM2 to PSM0)
If the conditions to switch V
SWOUT
from V
BAT
to V
DD
occur (see
the Battery Switchover section), the operating mode switches to
PSM0. When this switch occurs, the analog circuitry used in the
ADE energy measurement DSP automatically restarts. Note that
code execution continues normally. A software reset can be perf-
ormed to start PSM0 code execution at the power-on reset vector.
USING THE POWER MANAGEMENT FEATURES
Because program flow is different for each operating mode, the
status of V
SWOUT
must be known at all times. The VSWSOURCE
bit in the peripheral configuration SFR (PERIPH, Address
0xF4) indicates the power supply to which V
SWOUT
is connected
(see Table 20 ). This bit can be used to control program flow on
wake-up. Because code execution always starts at the power-on
reset vector, Bit 6 of the PERIPH SFR can be tested to determine
which power supply is being used and to branch to normal code
execution or to wake up event code execution. Power supply
events can also occur when the MCU core is active. To be aware
of the events that change what V
SWOUT
is connected to, use the
following guidelines:
• Enable the battery switchover interrupt (EBSO)
if V
SWOUT
= V
DD
at power-up.
• Enable the power supply restored interrupt (EPSR)
if V
SWOUT
= V
BAT
at power-up.
An early warning that battery switchover is about to occur is
provided by SAG detection and, possibly, by low V
DCIN
detection
(see the Battery Switchover section).
For a user-controlled battery switchover, enable automatic
battery switchover on low V
DD
only. Next, enable the low V
DCIN
event to generate the PSM interrupt. When a low V
DCIN
event
occurs, start data backup. Upon completion of the data backup,
enable battery switchover on low V
DCIN
. Battery switchover
occurs 30 ms later.
PSM1
BATTERY MODE
V
SWOUT
CONNECTED TO V
BAT
PSM0
NORMAL MODE
V
SWOUT
CONNECTED TO V
DD
PSM2
SLEEP MODE
V
SWOUT
CONNECTED TO V
BAT
POWER SUPPLY
RESTORED
AUTOMATIC BATTERY
SWITCHOVER
WAKE-UP
EVENT
USER CODE DIRECTS MCU
TO SHUT DOWN CORE AFTER
SERVICING WAKE-UP EVENT
POWER SUPPLY
RESTORED
06353-017
Figure 38. Transitioning Between Operating Modes