Freescale Semiconductor FRDM-FXS-MULTI 데이터 시트
MMA8652FC
Sensors
Freescale Semiconductor, Inc.
Freescale Semiconductor, Inc.
43
6.9.3
0x1F TRANSIENT_THS register
The Transient Threshold register sets the threshold limit for the detection of the transient acceleration. The value in the
TRANSIENT_THS register corresponds to a g value, which is compared against the values of high-pass filtered data. If the high-
pass filtered acceleration value exceeds the threshold limit, an event flag is raised and the interrupt is generated (if enabled).
TRANSIENT_THS register corresponds to a g value, which is compared against the values of high-pass filtered data. If the high-
pass filtered acceleration value exceeds the threshold limit, an event flag is raised and the interrupt is generated (if enabled).
6.9.4
0x20 TRANSIENT_COUNT register
The TRANSIENT_COUNT sets the minimum number of debounce counts continuously matching the condition where the
unsigned value of high-pass filtered data is greater than the user-specified value of TRANSIENT_THS.
unsigned value of high-pass filtered data is greater than the user-specified value of TRANSIENT_THS.
The time step for the transient detection debounce counter is set by the value of the system ODR and the Oversampling mode.
Table 62. 0x1F TRANSIENT_THS register (Read/Write)
Back to Register Address Map
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DBCNTM
THS6
THS5
THS4
THS3
THS2
THS1
THS0
Table 63. TRANSIENT_THS register
Bit(s)
Field
Description
Notes
7
DBCNTM
Debounce counter mode selection
0 Increments or decrements debounce (default)
1 Increments or clears counter
0 Increments or decrements debounce (default)
1 Increments or clears counter
6–0
THS[6:0]
Transient Threshold
A 7-bit unsigned number, with 0.063 g/LSB.
The maximum threshold is ±8 g.
000_0000 (default)
A 7-bit unsigned number, with 0.063 g/LSB.
The maximum threshold is ±8 g.
000_0000 (default)
Even if the part is set to full scale at ±2 g (or ±4 g), this
function will still operate up to ±8 g.
function will still operate up to ±8 g.
Table 64. 0x20 TRANSIENT_COUNT register (Read/Write)
Back to Register Address Map
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
D7
D6
D5
D4
D3
D2
D1
D0
Table 65. TRANSIENT_COUNT register
Bit(s)
Field
Description
7–0
D[7:0]
Count value
0000_0000 (default)
0000_0000 (default)
Table 66. TRANSIENT_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