LPS35HW datasheet(32/48 Pages) STMICROELECTRONICS

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LPS35HW

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Figure 20: "Threshold based" interrupt event

If AUTOZERO bit is set to '1', the measured pressure is used as reference on the register

REF_P (15h, 16h and 17h). From now on, the output pressure registers PRESS_OUT

(PRESS_OUT_H(2Ah), PRESS_OUT_L(29h) and PRESS_OUT_XL(28h)) are updated

and the same value is also used for the interrupt generation: PRESS_OUT = measured

pressure - REF_P

After the first conversion AUTOZERO bit is automatically set to '0'. To return back to

normal mode, RESET_AZ bit has to be set to '1'. This reset also the content of the REF_P

registers. If AUTORIFP bit is set to '1', the measured pressure is used as reference on the

(PRESS_OUT_H(2Ah), PRESS_OUT_L(29h) and PRESS_OUT_XL(28h)) show the

difference between the measured pressure and the content of the RPDS registers (18h and

19h): PRESS_OUT = measured pressure - RPDS*256

After the first conversion AUTORIFP bit is automatically set to '0'. To return back to normal

mode, RESET_ARP bit has to be set to '1'.

8.2

THS_P_L (0Ch)

Least significant bits of the threshold value for pressure interrupt generation.

8.3

THS_P_H (0Dh)

Most significant bits of the threshold value for pressure interrupt generation.

THS15

THS14

THS13

THS12

THS11

THS10

THS9

THS8

THS[15:8]

This register contains the high part of threshold value for pressure interrupt generation.

Refer to Section 10.2: "THS_P_L (0Ch)"

8.4

WHO_AM_I

Device Who am I

Table 17: WHO_AM_I register

LPS35HW Datasheet(PDF) 32 Page - STMicroelectronics