MMA8452Q

Sensors

22

Freescale Semiconductor, Inc.

0x0D: WHO_AM_I Device ID Register

The device identification register identifies the part. The default value is 0x2A. This value is factory programmed. Consult the

factory for custom alternate values.

0x0E: XYZ_DATA_CFG Register

The XYZ_DATA_CFG register sets the dynamic range and sets the high-pass filter for the output data. When the HPF_OUT

bit is set. The data registers 0x01 - 0x06 will contain high-pass filtered data when this bit is set.

The default full scale value range is 2g and the high-pass filter is disabled.

0x0F: HP_FILTER_CUTOFF High-Pass Filter Register

This register sets the high-pass filter cutoff frequency for removal of the offset and slower changing acceleration data. The

output of this filter is indicated by the data registers (0x01-0x06) when bit 4 (HPF_OUT) of Register 0x0E is set. The filter cutoff

options change based on the data rate selected as shown in Table 18. For details of implementation on the high-pass filter, refer

to Freescale application note AN4071.

0x0D: WHO_AM_I Device ID Register (Read Only)

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

010

1

0

1

0

0x0E: XYZ_DATA_CFG (Read/Write)

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

00

0

HPF_OUT

0

0

FS1

FS0

Table 15. XYZ Data Configuration Descriptions

HPF_OUT

Enable High-Pass output data 1 = output data high-pass filtered. Default value: 0

FS[1:0]

Output buffer data format full scale. Default value: 00 (2g).

Table 16. Full Scale Range

FS1

FS0

Full Scale Range

00

2

01

4

10

8

11

Reserved

0x0F: HP_FILTER_CUTOFF: High-Pass Filter Register (Read/Write)

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

0

0

Pulse_HPF_BYP Pulse_LPF_EN

0

0

SEL1

SEL0

Table 17. High-Pass Filter Cutoff Register Descriptions

Pulse_HPF_BYP

Bypass High-Pass Filter for Pulse Processing Function.

0: HPF enabled for Pulse Processing, 1: HPF Bypassed for Pulse Processing

Default value: 0.

Pulse_LPF_EN

Enable Low-Pass Filter for Pulse Processing Function.

0: LPF disabled for Pulse Processing, 1: LPF Enabled for Pulse Processing

Default value: 0.

SEL[1:0]

HPF Cutoff frequency selection.

Default value: 00 (see

Table 18).