DocID027112 Rev 2

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LPS25HB

Register description

40

output registers is not updated until both MSB and LSB are read, avoiding the reading of

values related to different samples.

The RESET_AZ bit is used to reset the AutoZero function. Resetting REF_P_H (0Ah),

REF_P_L (09h) and REF_P_XL (08h) sets the pressure reference registers RPDS_H (3Ah)

and RPDS_L (39h) to the default value. RESET_AZ is self-cleared. For the AutoZero

function please refer to CTRL_REG2 (21h).

The SIM bit selects the SPI serial interface mode:

•

0: (default value) 4-wire SPI interface mode selected;

•

1: 3-wire SPI interface mode selected.

8.7

CTRL_REG2 (21h)

Control register 2

The BOOT bit is used to refresh the content of the internal registers stored in the Flash

memory block. At device power-up the content of the Flash memory block is transferred to

the internal registers related to the trimming functions to allow correct behavior of the device

itself. If for any reason the content of the trimming registers is modified, it is sufficient to use

this bit to restore the correct values. When the BOOT bit is set to ‘1’, the content of the

internal Flash is copied inside the corresponding internal registers and is used to calibrate

the device. These values are factory trimmed and they are different for every device. They

allow correct behavior of the device and normally they should not be changed. At the end of

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32

1

0

BOOT

FIFO_EN

STOP_ON_FT FIFO_MEAN_

I2C_EN

SWRESET

AUTO_ZERO

ONE_SHOT

BOOT

Reboot memory content. Default value: 0.

(0: normal mode; 1: reboot memory content). The bit is self-cleared when the BOOT

is completed.

FIFO_EN

FIFO enable. Default value: 0.

(0: disable; 1: enable)

STOP_ON_FTH

Stop on FIFO threshold. Enable FIFO watermark level use. Default value 0

(0: disable; 1: enable).

FIFO_MEAN_-

DEC

Register address automatically incremented during a multiple byte access with a

(0: disable; 1 enable)

I2C_EN

SWRESET

Software reset. Default value: 0.

(0: normal mode; 1: software reset).

The bit is self-cleared when the reset is completed.

AUTOZERO

Autozero enable. Default value: 0.

(0: normal mode; 1: Autozero enabled)

ONE_SHOT

One shot mode enable. Default value: 0.

(0: idle mode; 1: a new dataset is acquired)