Datasheet

ADE5166/ADE5169/ADE5566/ADE5569 Data Sheet
Rev. D | Page 38 of 156
TRANSITIONING BETWEEN OPERATING MODES
The operating mode of the ADE5166/ADE5169/ADE5566/
ADE5569 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 switch-
over 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, user code can initiate a transition to PSM2 mode.
Entering Sleep Mode (PSM1 to PSM2)
To reduce power consumption when V
SWOUT
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 ADE5166/ADE5169/ADE5566/ADE5569 may need to
wake up from PSM2 mode to service wake-up events (see the
3.3 V Peripherals and Wake-Up Events section). PSM1 code
execution begins at the power-on reset vector. After servicing
the wake-up event, the ADE5166/ADE5169/ADE5566/ADE5569
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
mode. When this switch occurs, the MCU core and the analog
circuitry used in the ADE energy measurement DSP automatically
restart. PSM0 code execution begins at the power-on reset vector.
Automatic Switch to V
DD
(PSM1 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 mode. 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 performed 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 SRF 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
IS CONNECTED TO V
BAT
PSM0
NORMAL MODE
V
SWOUT
IS CONNECTED TO V
DD
PSM2
SLEEP MODE
V
SWOUT
IS CONNECTED TO V
BAT
POWER SUPPLY
RESTORED
AUTOMATIC BATTERY
SWITCHOVER
WAKE-UP
EVENT
USER CODE DIRECTS MCU
TO SHUT DOWN CORE AFTER
SERVICING A WAKE-UP EVENT
POWER SUPPLY
RESTORED
07411-017
Figure 38. Transitioning Between Operating Modes