Datasheet
Sensors
NXP Semiconductors 35
MMA8452Q
When the EA bit gets set while ELE = 1, all status bits (AxZ, AxY, AxZ, DPE, and PolX, PolY, PolZ) are frozen. Reading the
PULSE_SRC register clears all bits. Reading the source register will clear the interrupt.
0x23 - 0x25: PULSE_THSX, Y, Z pulse threshold for X, Y and Z registers
The pulse threshold can be set separately for the X, Y and Z axes. The PULSE_THSX, PULSE_THSY and PULSE_THSZ
registers define the threshold which is used by the system to start the pulse detection procedure.
Table 37. PULSE_SRC description
Field Description
EA
Event active flag. Default value: 0.
(0: No interrupt has been generated; 1: One or more interrupt events have been generated)
AxZ
Z-axis event. Default value: 0.
(0: No interrupt; 1: Z-axis event has occurred)
AxY
Y-axis event. Default value: 0.
(0: No interrupt; 1: Y-axis event has occurred)
AxX
X-axis event. Default value: 0.
(0: No interrupt; 1: X-axis event has occurred)
DPE
Double pulse on first event. Default value: 0.
(0: Single-pulse event triggered interrupt; 1: Double pulse event triggered interrupt)
PolZ
Pulse polarity of Z-axis event. Default value: 0.
(0: Pulse event that triggered interrupt was positive; 1: Pulse event that triggered interrupt was negative)
PolY
Pulse polarity of Y-axis event. Default value: 0.
(0: Pulse event that triggered interrupt was positive; 1: Pulse event that triggered interrupt was negative)
PolX
Pulse polarity of X-axis event. Default value: 0.
(0: Pulse event that triggered interrupt was positive; 1: Pulse event that triggered interrupt was negative)
0x23: PULSE_THSX register (read/write)
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
0 THSX6 THSX5 THSX4 THSX3 THSX2 THSX1 THSX0
Table 38. PULSE_THSX description
Field Description
THSX[6:0]
Pulse threshold on X-axis. Default value: 000_0000.
0x24: PULSE_THSY register (read/write)
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
0 THSY6 THSY5 THSY4 THSY3 THSY2 THSY1 THSY0
Table 39. PULSE_THSY description
Field Description
THSY[6:0]
Pulse threshold on Y-axis. Default value: 000_0000.
0x25: PULSE_THSZ register (read/write)
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
0 THSZ6 THSZ5 THSZ4 THSZ3 THSZ2 THSZ1 THSZ0
Table 40. PULSE_THSZ description
Field Description
THSZ[6:0]
Pulse threshold on Z-axis. Default value: 000_0000.