LSM9DS0 Datasheet, PDF (24/74 Pages) STMicroelectronics – iNEMO inertial module 3D accelerometer, 3D gyroscope, 3D magnetometer

Functionality
LSM9DS0
4.3
Gyroscope digital main blocks
Figure 5. Gyroscope block diagram
Out_Sel
00
01
DataReg
0
FIFO
LPF2
10
11
32x16x3
ADC LPF1
HPF
1
I²C
HPen
INT1_Sel
SPI
10
11
Interrupt
01
generator
00
4.3.1
4.3.2
SCR REG
CONF REG
INT
GAMS250320131444FSR
FIFO
The LSM9DS0 embeds 32 slots of 16-bit data FIFO for each of the three output channels:
yaw, pitch and roll. This allows consistent power saving for the system, since the host
processor does not need to continuously poll data from the sensor, but can wake up only
when needed and burst the significant data out from the FIFO. This buffer can work
accordingly in five different modes: Bypass mode, FIFO mode, Stream mode, Bypass-to-
Stream mode and Stream-to-FIFO mode. Each mode is selected by the FIFO_MODE bits in
FIFO_CTRL_REG_G (2Eh). A programmable watermark level, FIFO_Empty or FIFO_Full
events can be enabled to generate dedicated interrupts on the DRDY_G pin (configured
through CTRL_REG3_G (22h) and event detection information is available in
FIFO_SRC_REG_G (2Fh). The watermark level can be configured to WTM4:0 in
FIFO_CTRL_REG_G (2Eh).
Bypass mode
In Bypass mode, the FIFO is not operational and for this reason it remains empty. As
described in Figure 6, for each channel only the first address is used. The remaining FIFO
slots are empty. When new data is available, the old data is overwritten.
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