BLUENRG-MS datasheet(19/42 Pages) STMICROELECTRONICS

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BlueNRG-MS

Operating modes

Several operating modes are defined for the BlueNRG-MS:

•

Reset mode

•

Sleep mode

•

Standby mode

•

Active mode

•

Radio mode

−

Receive Radio mode

−

Transmit Radio mode

In Reset mode, the BlueNRG-MS is in ultra-low power consumption: all voltage regulators,

clocks and the RF interface are not powered. The BlueNRG-MS enters Reset mode by

asserting the external reset signal. As soon as it is de-asserted, the device follows the

normal activation sequence to transit to Active mode.

In Sleep mode either the low speed crystal oscillator or the low speed ring oscillator are

running, whereas the high speed oscillators are powered down as well as the RF interface.

The state of the BlueNRG-MS is retained and the content of the RAM is preserved.

Depending on the application, part of the RAM (RAM2 block) can be switched off during

sleep to save more power (refer to stack mode 1, described in UM1868).

While in Sleep mode, the BlueNRG-MS waits until an internal timer expires and then it

goes into Active mode. The transition from Sleep mode to Active mode can also be

activated through the SPI interface.

Standby mode and Sleep mode are equivalent but the low speed frequency oscillators are

powered down. In Standby mode the BlueNRG-MS can be activated through the SPI

interface.

In Active mode the BlueNRG-MS is fully operational: all interfaces, including SPI and RF,

are active as well as all internal power supplies together with the high speed frequency

oscillator. The MCU core is also running.

Radio mode differs from Active mode as also the RF transceiver is active and it is capable

of either transmitting or receiving.

Figure 12 reports the simplified state machine:

DocID027103 Rev 6

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BLUENRG-MS Datasheet(PDF) 19 Page - STMicroelectronics