Datasheet

L3G4200D Main digital blocks
Doc ID 17116 Rev 3 19/42
3.2.5 Stream-to-FIFO mode
In stream-to-FIFO mode, data from yaw, pitch, and roll measurements are stored in the
FIFO. A watermark interrupt can be enabled on pin DRDY/INT2, setting the I2_WTM bit in
CTRL_REG3, which is triggered when the FIFO is filled to the level specified in the WTM4:0
bits of FIFO_CTRL_REG. The FIFO continues filling until full (32 slots of 16-bit data for yaw,
pitch, and roll). When full, the FIFO discards the older data as the new data arrives. Once a
trigger event occurs (related to INT1_CFG register events), the FIFO starts operating in
FIFO mode (see Figure 11).
Figure 11. Trigger stream mode
3.2.6 Retrieve data from FIFO
FIFO data is read through the OUT_X, OUT_Y and OUT_Z registers. When the FIFO is in
stream, trigger or FIFO mode, a read operation to the OUT_X, OUT_Y or OUT_Z registers
provides the data stored in the FIFO. Each time data is read from the FIFO, the oldest pitch,
roll, and yaw data are placed in the OUT_X, OUT_Y and OUT_Z registers and both single
read and read_burst (X,Y & Z with auto-incremental address) operations can be used. In
read_burst mode, when data included in OUT_Z_H is read, the system again starts to read
information from addr OUT_X_L.
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