Freescale Semiconductor Energy Efficient Solutions Xtrinsic MMA8452Q, Data Sheet: Technical Data

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MMA8452Q
Sensors
34 Freescale Semiconductor, Inc.
0x27: PULSE_LTCY Pulse Latency Timer Register
The bits LTCY7 through LTCY0 define the time interval that starts after the first pulse detection. During this time interval, all
pulses are ignored. Note: This timer must be set for single pulse and for double pulse.
The minimum time step for the pulse latency is defined in Table 45 and Table 46 . The maximum time is the time step at the ODR
and Oversampling mode multiplied by 255. The timing also changes when the Pulse LPF is enabled or disabled.
Table 43. Time Step for PULSE Time Limit (Reg 0x0F) Pulse_LPF_EN = 0
ODR (Hz)
Max Time Range (s) Time Step (ms)
Normal LPLN HighRes LP Normal LPLN HighRes LP
800 0.159 0.159 0.159 0.159 0.625 0.625 0.625 0.625
400 0.159 0.159 0.159 0.319 0.625 0.625 0.625 1.25
200 0.319 0.319 0.159 0.638 1.25 1.25 0.625 2.5
100 0.638 0.638 0.159 1.28 2.5 2.5 0.625 5
50 1.28 1.28 0.159 2.55 5 5 0.625 10
12.5 1.28 5.1 0.159 10.2 5 20 0.625 40
6.25 1.28 5.1 0.159 10.2 5 20 0.625 40
1.56 1.28 5.1 0.159 10.2 5 20 0.625 40
0x27: PULSE_LTCY Register (Read/Write)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
LTCY7 LTCY6 LTCY5 LTCY4 LTCY3 LTCY2 LTCY1 LTCY0
Table 44. PULSE_LTCY Description
LTCY[7:0] Latency Time Limit. Default value: 0000_0000
Table 45. Time Step for PULSE Latency @ ODR and Power Mode (Reg 0x0F) Pulse_LPF_EN = 1
ODR (Hz)
Max Time Range (s) Time Step (ms)
Normal LPLN HighRes LP Normal LPLN HighRes LP
800 0.638 0.638 0.638 0.638 2.5 2.5 2.5 2.5
400 1.276 1.276 1.276 1.276 5 5 5 5
200 2.56 2.56 1.276 2.56 10 10 5 10
100 5.1 5.1 1.276 5.1 20 20 5 20
50 10.2 10.2 1.276 10.2 40 40 5 40
12.5 10.2 40.8 1.276 40.8 40 160 5 160
6.25 10.2 40.8 1.276 81.6 40 160 5 320
1.56 10.2 40.8 1.276 81.6 40 160 5 320
Table 46. Time Step for PULSE Latency @ ODR and Power Mode (Reg 0x0F) Pulse_LPF_EN = 0
ODR (Hz)
Max Time Range (s) Time Step (ms)
Normal LPLN HighRes LP Normal LPLN HighRes LP
800 0.318 0.318 0.318 0.318 1.25 1.25 1.25 1.25
400 0.318 0.318 0.318 0.638 1.25 1.25 1.25 2.5
200 0.638 0.638 0.318 1.276 2.5 2.5 1.25 5
100 1.276 1.276 0.318 2.56 5 5 1.25 10
50 2.56 2.56 0.318 5.1 10 10 1.25 20
12.5 2.56 10.2 0.318 20.4 10 40 1.25 80
6.25 2.56 10.2 0.318 20.4 10 40 1.25 80
1.56 2.56 10.2 0.318 20.4 10 40 1.25 80