± 2g / 4g / 8g / 16g Tri-axis Digital
Accelerometer Technical
Reference Manual
PART NUMBER:
KX132-1211
Rev. 1.0
31-Jul-2019
36 Thornwood Dr.
–
Ithaca, NY 14850
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–
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Page
43
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73
BUF_CNTL2
Read/write control register that controls sample buffer operation. This register is On-The-Fly (OTF) register and can be
written to while the KX132-1211
is enabled (PC1 bit in CNTL1 register is set to “1”) and the change will be accepted
with no interruption in the operation.
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
BUFE
BRES
BFIE
0
0
0
BM1
BM0
Reset Value
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
00000000
Address:
0x5F
BUFE
–
controls activation of the sample buffer.
BUFE = 0
– sample buffer inactive
BUFE = 1
– sample buffer active
Note 1: Disabling the sample buffer (BUFE = 0) will clear the buffer. The buffer will also be
cleared (1) following write to BUF_CLEAR register and/or (2) after setting PC1 bit in CNTL1
register to 0 (standby mode).
Note 2: Additional control of data to be buffered is available via ADP_BUF_SEL bit7 in
ADP_CNTL2 register.
BRES
–
determines the resolution of the acceleration data samples collected by the sample buffer.
BRES = 0
– 8-bit samples are accumulated in the buffer
BRES = 1
– 16-bit samples are accumulated in the buffer
BFIE
–
buffer full interrupt enable bit
BFIE = 0
– buffer full interrupt is disabled
BFIE = 1
– buffer full interrupt is enabled and updated in INS2
BM1, BM0 selects the operating mode of the sample buffer per Table 16.
BM1
BM0
Mode
Description
0
0
FIFO
The buffer collects 171 sets of 8-bit low resolution values or 86 sets of 16-bit
high resolution values and then stops collecting data, collecting new data only
when the buffer is not full.
0
1
Stream
The buffer holds the last 171 sets of 8-bit low resolution values or 86 sets of
16-bit high resolution values. Once the buffer is full, the oldest data is
discarded to make room for newer data.
1
0
Trigger
When a trigger event occurs, the buffer holds the last data set of SMP[9:0]
samples before the trigger event and then continues to collect data until full.
New data is collected only when the buffer is not full.
Table 16:
Selected Buffer Mode
