Register description

LPS331AP

22/36

Doc ID 022112 Rev 7

CTRL_REG2

Control register 2

Address:

21h

Type:

R/W

Description:

Control register.

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

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

internal registers related to trimming functions to permit a good 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 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 permit good

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

process the BOOT bit is set again to ‘0’.

BOOT bit takes effect after one ODR clock cycle.

SWRESET is the software reset bit. The device is reset to the power on configuration if the

SWRESET bit is set to ‘1’ and BOOT is set to ‘1’.

AUTO_ZERO, when set to ‘1’, the actual pressure output is copied in the REF_P_H &

REF_P_L & REF_P_XL and kept as reference and the PRESS_OUT_H & PRESS_OUT_L

& PRESS _OUT_XL is the difference between this reference and the pressure sensor value.

ONE_SHOT bit is used to start a new conversion when ODR1-ODR0 bits in CTRL_REG1

are set to “000”. In this situation a single acquisition of temperature and pressure is started

when ONE_SHOT bit is set to ‘1’. At the end of conversion the new data are available in the

output registers, the STAUS_REG[0] and STAUS_REG[1] bits are set to ‘1’ and the

ONE_SHOT bit comes back to ‘0’ by hardware.

76

543

210

BOOT

RESERVED

SWRESET

AUTO_ZERO

ONE_SHOT

[7] BOOT: Reboot memory content. Default value: 0

(0: normal mode; 1: reboot memory content)

[6:3] RESERVED

[2] Software reset. Default value: 0

(0: normal mode; 1: software reset)

[1] Autozero enable. Default value: 0

(0: normal mode; 1: autozero enable)

[0] One shot enable. Default value: 0

(0: waiting for start of conversion; 1: start for a new dataset)