± 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
© 2019 Kionix
–
All Rights Reserved
tel: 607-257-1080 – fax:607-257-1146
893-12874-1907311402-0.17
www.kionix.com -
Page
69
of
73
In trigger mode, data is accumulated in the buffer sequentially until the Sample Threshold is reached. Once the Sample
Threshold is reached, the oldest samples are discarded when new samples are collected. Note in Figure 26
how Data0
was thrown out to make room for Data8.
Index
Sample
0
Data1
← Trigger read pointer
1
Data2
2
Data3
3
Data4
4
Data5
5
Data6
6
Data7
Trigger write
pointer →
7
Data8
← Sample Threshold
8
9
Figure 26:
Additional Data Prior to Trigger Event
After a trigger event occurs, the buffer no longer discards the oldest samples, and instead begins accumulating samples
sequentially until full. The buffer then stops collecting samples, as seen in Figure 27. This results in the buffer holding
SMP_TH [7:0] samples prior to the trigger event, and SMPX samples after the trigger event.
Index
Sample
0
Data1
← Trigger read pointer
1
Data2
2
Data3
3
Data4
4
Data5
5
Data6
6
Data7
7
Data8
← Sample Threshold
8
Data9
9
Data10
Figure 27:
Additional Data after Trigger Event
