AN92584 Datasheet, PDF (36/42 Pages) Ramtron International Corporation – Designing for Low Power and Estimating Battery Life for BLE Applications

Designing for Low Power and Estimating Battery Life for BLE Applications
Stage
A
B
C
D
I
H
E
F
J
G
Table 14. Advertising Current Profile Stages
BLESS Internal State
BLESS Operation
CYBLE_BLESS_STATE_ECO_ON
Oscillator Startup
CYBLE_BLESS_STATE_ECO_STABLE Oscillator Stabilization
CYBLE_BLESS_STATE_ACTIVE
CYBLE_BLESS_STATE_ACTIVE
CYBLE_BLESS_STATE_ACTIVE
CYBLE_BLESS_STATE_ACTIVE
CYBLE_BLESS_STATE_ACTIVE
Event Start Delay
ADV Transmit
Inter-Frame Space
Receive
Inter-Channel Delay
Power Modes
BLESS
System
DEEPSLEEP
Active
Deep-Sleep
DEEPSLEEP
Active
Sleep
ACTIVE
Active
Sleep
ACTIVE
Sleep
ACTIVE
Sleep
ACTIVE
Sleep
ACTIVE
Sleep
CYBLE_BLESS_STATE_EVENT
CLOSE
Post-Processing
ACTIVE
Active
CYBLE_BLESS_STATE_DEEPSLEEP
CYBLE_BLESS_STATE_DEEPSLEEP
Enter Deep-Sleep
two LFCLK cycles)
Deep-Sleep
(takes
DEEPSLEEP
DEEPSLEEP
Sleep
Deep-Sleep
The BLESS is in the DEEPSLEEP mode (stage G) between advertising events. The system may also be in the Deep-
Sleep mode if no processing is required. The BLESS maintains the link timing by using the WCO clock because the
ECO is OFF. The BLESS automatically wakes up at the programmed instant before the start of the advertising event
and generates an interrupt.
A – The BLESS interrupt wakes up the system from the Deep-Sleep mode. The BLE Component turns ON the ECO
at the beginning of the stage. The ECO ramps up by the end of stage A with a stable clock amplitude. The ramp up
takes approximately 400 µs. The application can put the system back into the Deep-Sleep mode until the ECO is
ready. The ECO interrupts the CPU once the amplitude is stable.
B – The ECO requires more time to stabilize the frequency. The application puts the system into the Sleep mode
during this period. This stabilization takes approximately 400 µs. At the end of stage B, the BLESS wakes up from the
DEEPSLEEP mode. It switches from the WCO clock to the stable ECO clock and generates an interrupt.
C – The BLESS interrupt wakes up the CPU. The BLESS enters the ACTIVE mode. If no processing is required, the
application puts the system again into the Sleep mode. The system may remain in the Sleep mode until all BLE
transactions are completed in stage F. The system remains in this stage until the start of the advertising event.
D – In the advertising event, the Peripheral transmits the advertising packets. The entire BLESS including the RF is
active during this period. The advertising packets are transmitted on the three advertising channels.
I – After transmitting the advertising packet, the Peripheral waits for an Inter-Frame Space time interval (T_IFS) of
150 µs (per the BLE specification) to listen to the peer device. This stage is optional and depends on the advertising
type settings.
H – After an Inter-Frame Space time interval, the Peripheral listens on the same channel for a packet from the peer
device. The BLESS times out and stops listening if no packet is received within a specific time. If a packet is received,
it continues to receive until the end of the packet. This state is optional and depends on the advertising type settings.
E – The three packets are spaced at an interval of 1.25 ms. The BLESS is idle during this interval between the
transmissions.
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Document No. 001-92584 Rev. *A
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