Register description

LIS3DHH

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DocID030220 Rev 3

7.13

FIFO_SRC (2Fh)

FIFO status register.

Table 29. FIFO_SRC register

Table 30. FIFO_SRC register description

The FSS is the FIFO stored data level of the unread samples. When it is equal to FTH, all

data available in FIFO are read without additional read operations.

The INT output is high when the number of samples to read is equal to or greater than FTH.

Figure 16. Continuous mode: FTH/FSS details

FTH

OVRN

FSS5

FSS4

FSS3

FSS2

FSS1

FSS0

FTH

FIFO threshold status.

(0: FIFO filling is lower than threshold level; 1: FIFO filling is equal to or higher than

the threshold level

OVRN

FIFO overrun status.

(0: FIFO is not completely filled; 1: FIFO is completely filled and at least one sample

has been overwritten) For further details refer to Table 31.

FSS [5:0]

Number of unread samples stored in FIFO.

(000000: FIFO empty; 100000: FIFO full, 32 unread samples)

For further details refer to Table 31.

Table 31. FIFO_SRC example: OVR/FSS details

FTH

OVRN

FSS5

FSS4

FSS3

FSS2

FSS1

FSS0

Description

0

0

000000

FIFO empty

--(1)

1. When the number of unread samples in FIFO is equal to or greater than the threshold level set in register

FIFO_CTRL (2Eh), the FTH value is ‘1’.

0

0

000011 unread sample

...

--(1)

0

1

0000032 unread samples

0(1)

1

1

00000

At least one sample has

been overwritten