MPL3115A2

Sensors

Freescale Semiconductor, Inc.

25

7.2

Device ID

7.2.1

WHO_AM_I (0x0C)

Device identification register. This register contains the device identifier which is set to 0xC4 by default. The value is factory

programmed. Consult factory for custom alternate values.

7.3

FIFO Setup

7.3.1

F_STATUS (0x0D)

If the FIFO subsystem data output register driver is enabled, the status register indicates the current status information of the

FIFO subsystem.

The F_OVF and F_WMRK_FLAG flags remain asserted while the event source is still active, but the user can clear the FIFO

interrupt bit flag in the interrupt source register (INT_SOURCE) by reading the F_STATUS register. Therefore the F_OVF bit flag

will remain asserted while the FIFO has overflowed and the F_WMRK_FLAG bit flag will remain asserted while the F_CNT value

is greater than then F_WMRK value.

Table 24. WHO_AM_I Register

7

6543

21

0

R

W

Reset

(NVM data)

(NVM data)

(NVM data)

(NVM data)

(NVM data)

(NVM data)

(NVM data)

(NVM data)

11000

10

0

Table 25. F_STATUS

7

6

543210

R

F_OVF

F_WMRK_FLAG

F_CNT5

F_CNT4

F_CNT3

F_CNT2

F_CNT1

F_CNT0

W

Reset

0

0

000000

Table 26. FIFO Flag Event Descriptions

F_OVF

F_WMRK_FLAG

Event Description

0

—

No FIFO overflow events detected.

1

—

FIFO overflow event detected.

—

0

No FIFO watermark events detected.

—

1

FIFO watermark event detected. FIFO sample count greater than watermark value.

Table 27. FIFO Sample Count Bit Descriptions

Name

Description

F_CNT[5:0]

FIFO sample counter. F_CNT[5:0] bits indicate the number of samples currently stored in the FIFO buffer. Count

000000 indicates that the FIFO is empty.

Default value: 00_0000.

(000001 to 100000 indicates 1 to 32 samples stored in FIFO