Datasheet
MMA8451Q
Sensors
28 Freescale Semiconductor, Inc.
0x11: Portrait/Landscape Configuration Register
This register enables the Portrait/Landscape function and sets the behavior of the debounce counter.
0x12: Portrait/Landscape Debounce Counter
This register sets the debounce count for the orientation state transition. The minimum debounce latency is determined by the
data rate set by the product of the selected system ODR and PL_COUNT registers. Any transition from WAKE to SLEEP or vice
versa resets the internal Landscape/Portrait debounce counter. Note: The debounce counter weighting (time step) changes
based on the ODR and the Oversampling mode. Table 27 explains the time step value for all sample rates and all Oversampling
modes.
0x13: PL_BF_ZCOMP Back/Front and Z Compensation Register
The Z-Lock angle compensation bits allow the user to adjust the Z-lockout region from 14° up to 43°. The default Z-lockout angle
is set to the default value of 29° upon power up. The Back to Front trip angle is set by default to ±75° but this angle also can be
adjusted from a range of 65° to 80° with 5° step increments.
Note: All angles are accurate to ±2°.
0x11: PL_CFG Register (Read/Write)
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
DBCNTM PL_EN — — — — — —
Table 25. PL_CFG Description
DBCNTM
Debounce counter mode selection. Default value: 1
0: Decrements debounce whenever condition of interest is no longer valid.
1: Clears counter whenever condition of interest is no longer valid.
PL_EN
Portrait/Landscape Detection Enable. Default value: 0
0: Portrait/Landscape Detection is Disabled.
1: Portrait/Landscape Detection is Enabled.
0x12: PL_COUNT Register (Read/Write)
Bit
7
Bit
6
Bit
5
Bit
4
Bit
3
Bit
2
Bit
1
Bit
0
DBNCE[7] DBNCE[6] DBNCE[5] DBNCE[4] DBNCE[3] DBNCE[2] DBNCE[1] DBNCE[0]
Table 26. PL_COUNT Description
DBCNE[7:0] Debounce Count value. Default value: 0000_0000.
Table 27.
PL_COUNT Relationship with the ODR
ODR (Hz)
Max Time Range (s) Time Step (ms)
Normal LPLN HighRes LP Normal LPLN HighRes LP
800 0.319 0.319 0.319 0.319 1.25 1.25 1.25 1.25
400 0.638 0.638 0.638 0.638 2.5 2.5 2.5 2.5
200 1.28 1.28 0.638 1.28 5 5 2.5 5
100 2.55 2.55 0.638 2.55 10 10 2.5 10
50 5.1 5.1 0.638 5.1 20 20 2.5 20
12.5 5.1 20.4 0.638 20.4 20 80 2.5 80
6.25 5.1 20.4 0.638 40.8 20 80 2.5 160
1.56 5.1 20.4 0.638 40.8 20 80 2.5 160
0x13: PL_BF_ZCOMP Register (Read/Write)
Bit
7
Bit
6
Bit
5
Bit 4 Bit
3
Bit
2
Bit
1
Bit
0
BKFR[1] BKFR[0] — — — ZLOCK[2] ZLOCK[1] ZLOCK[0]
Table 28. PL_BF_ZCOMP Description
BKFR[7:6]
Back/Front Trip Angle Threshold. Default: 01
≥ ±75°. Step size is 5°.
Range: ±(65° to 80°).
ZLOCK[2:0]
Z-Lock Angle Threshold. Range is from 14° to 43°. Step size is 4°.
Default value: 100
≥ 29°. Maximum value: 111 ≥ 43°.