LPS35HW Datasheet, PDF (32/48 Pages) STMicroelectronics – Embedded temperature compensation

Register description
Figure 20: "Threshold based" interrupt event
LPS35HW
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
register REF_P (15h, 16h and 17h). The output registers PRESS_OUT
(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.
7
THS15
6
THS14
5
THS13
4
THS12
3
THS11
2
THS10
1
THS9
0
THS8
8.4
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)"
WHO_AM_I
Device Who am I
7
6
1
0
Table 17: WHO_AM_I register
5
4
3
2
1
1
0
0
1
0
0
1
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