Sleep And Wake-Up Timer; Sleep And Wake-Up Timer Features; Sleep And Wake-Up Timer Overview; Configuring A Defined Sequence Order - Analog Devices ADuCM356 Reference Manual

Reference Manual

SLEEP AND WAKE-UP TIMER

SLEEP AND WAKE-UP TIMER FEATURES

The ADuCM356 integrates a 20-bit sleep and wake-up timer.
The sleep and wake-up timer provides automated control of the
sequencer and can run up to eight sequences sequentially in any

SLEEP AND WAKE-UP TIMER OVERVIEW

The sleep and wake-up timer block consists of a 20-bit timer
that counts down. The source clock is the 32 kHz, internal, low
frequency oscillator.
When the timer elapses, the device wakes up and runs a sequence
automatically. Up to eight sequences can run sequentially.
When the timer elapses, the device returns to sleep. If the timer
elapses before the sequence completes execution, the remaining
commands in the sequence are ignored. Therefore, the user code
must ensure that the values in the SEQxSLEEPx registers are large
enough to allow sequences to execute all commands.
It is recommended to use the wake-up timer to disable the timer
sleep function (AFE PWRMOD, Bit 2 = 0) and use the sequencer to
enter hibernate mode. Set the AFE PWRMOD register, Bit 3 = 1 to
enable the sequencer to put the device in hibernate mode.
CONFIGURING A DEFINED SEQUENCE
ORDER
The sleep and wake-up timer provides a feature that allows a
specific order of sequences to execute periodically. The order in
which the sequences are executed is defined in the SEQORDER
register. There are eight available slots in this register (A to H).
Each slot can be configured with any one of the four sequences.
Figure 36 shows an example diagram of this feature. There are four
defined sequences executed, SEQ0, SEQ1, SEQ2, and SEQ3, as
shown in Figure 36.
analog.com
order from SEQ0 to SEQ3. Each sequence has a defined sleep
period (SEQxSLEEPx) and a defined active period (SEQxWUPx).
The timer is clocked from the internal 32 kHz oscillator clock
source.
Figure 34. Sleep and Wake-Up Timer Block Diagram
Figure 35. Sleep and Wake-Up Timing Diagram
To configure the ADuCM356 to implement this sequence order,
implement the following register settings:
1. SEQORDER, Bits[1:0] = 00
2. SEQORDER, Bits[3:0] = 01
3. SEQORDER, Bits[5:4] = 10
4. SEQORDER, Bits[7:6] = 11
5. CON, Bits[3:1] = 011
RECOMMENDED SLEEP AND WAKE-UP TIMER
OPERATION
When using the sleep and wake-up timer to optimize performance
and power consumption, the following procedure is recommended:
1. Set the AFE PWRMOD register, Bit 2 to disable the timer
Figure 36. Sequence Order Diagram
sleep function. Note that the sleep and wake-up timer does
not place the device in hibernate mode. Instead, write to the
SEQTRGSLP register at the end of the sequence to place the
device in sleep mode. Sleep mode optimizes power consump-
tion.
ADuCM356
Rev. A | 143 of 312